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Water, Volume 9, Issue 11 (November 2017)

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Open AccessArticle Thermal Study on Extensive Green Roof Integrated Irrigation in Northwestern Arid Regions of China
Water 2017, 9(11), 810; doi:10.3390/w9110810
Received: 24 August 2017 / Revised: 17 October 2017 / Accepted: 19 October 2017 / Published: 9 November 2017
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Abstract
Selection of xerophils and drought tolerant plants is highly crucial in green roof techniques in the drought prone regions of Northwest China. In this study, the thermal performance under the natural conventional climate in summer was analyzed using a self-made simulation experimental platform
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Selection of xerophils and drought tolerant plants is highly crucial in green roof techniques in the drought prone regions of Northwest China. In this study, the thermal performance under the natural conventional climate in summer was analyzed using a self-made simulation experimental platform through comparison of the internal surface temperature with and without green roofs. The distribution frequency of internal surface temperature was investigated by dividing internal surface temperature into several ranges. Statistical analysis showed that the frequency of internal surface temperature lower than 33 °C for green roofs was 91.8%, about 1.09 times higher than that for non-green roofs, and that the sum of internal surface temperature exceeding 35 °C was about one third of that for non-green roofs. The results proved that green roofs have a significant insulation effect. Moreover, the thermal insulation property of green roofs had a strong positive relation with outside temperature. The thermal insulation characteristic was improved as the outdoor temperature increased, additionally, it had a better insulation effect within two hours after irrigation. Full article
(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)
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Open AccessArticle Analysis of Coastline Extraction from Landsat-8 OLI Imagery
Water 2017, 9(11), 816; doi:10.3390/w9110816
Received: 15 September 2017 / Revised: 18 October 2017 / Accepted: 21 October 2017 / Published: 25 October 2017
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Abstract
Coastline extraction is a fundamental work for coastal resource management, coastal environmental protection and coastal sustainable development. Due to the free access and long-term record, Landsat series images have the potential to be used for coastline extraction. However, dynamic features of different types
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Coastline extraction is a fundamental work for coastal resource management, coastal environmental protection and coastal sustainable development. Due to the free access and long-term record, Landsat series images have the potential to be used for coastline extraction. However, dynamic features of different types of coastlines (e.g., rocky, sandy, artificial), caused by sea level fluctuation from tidal, storm and reclamation, make it difficult to be accurately extracted with coarse spatial resolution, e.g., 30 m, of Landsat images. To access this problem, we analyze the performance of coastline extraction by integrating downscaling, pansharpening and water index approaches in increasing the accuracy of coastline extraction from the latest Landsat-8 Operational Land Imager (OLI) imagery. In order to prove the availability of the proposed method, we designed three strategies: (1) Strategy 1 uses the traditional water index method to extract coastline directly from original 30 m Landsat-8 OLI multispectral (MS) image; (2) Strategy 2 extracts coastlines from 15 m fused MS images generated by integrating 15 m panchromatic (PAN) band and 30 m MS image with ten pansharpening algorithms; (3) Strategy 3 first downscales the PAN band to a finer spatial resolution (e.g., 7.5 m) band, and then extracts coastlines from pansharpened MS images generated by integrating downscaled spatial resolution PAN band and 30 m MS image with ten pansharpening algorithms. Using the coastline extracted from ZiYuan-3 (ZY-3) 5.8 m MS image as reference, accuracies of coastlines extracted from MS images in three strategies were validated visually and quantitatively. The results show that, compared with coastline extracted directly from 30 m Landsat-8 MS image (strategy 1), strategy 3 achieves the best accuracies with optimal mean net shoreline movement (MNSM) of −2.54 m and optimal mean absolute difference (MAD) of 11.26 m, followed by coastlines extracted in strategy 2 with optimal MNSM of −4.23 m and optimal MAD of 13.54 m. Further comparisons with single-band thresholding (Band 6), AWEI, and ISODATA also confirmed the superiority of strategy 3. For the various used pansharpening algorithms, five multiresolution analysis MRA-based pansharpening algorithms are more efficient than the component substitution CS-based pansharpening algorithms for coastline extraction from Landsat-8 OLI imagery. Among the five MRA-based fusion methods, the coastlines extracted from the fused images generated by Indusion, additive à trous wavelet transform (ATWT) and additive wavelet luminance proportional (AWLP) produced the most accurate and visually realistic representation. Therefore, pansharpening approaches can improve the accuracy of coastline extraction from Landsat-8 OLI imagery, and downscaling the PAN band to finer spatial resolution is able to further improve the coastline extraction accuracy, especially in crenulated coasts. Full article
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Open AccessFeature PaperArticle Substrate Composition and Depth Affect Soil Moisture Behavior and Plant-Soil Relationship on Mediterranean Extensive Green Roofs
Water 2017, 9(11), 817; doi:10.3390/w9110817
Received: 31 August 2017 / Revised: 16 October 2017 / Accepted: 19 October 2017 / Published: 25 October 2017
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Abstract
The Mediterranean basin is extremely vulnerable to climate change, and one of the areas most impacted by human water demand. Yet the green roofs increasingly created both for aesthetic reasons and to limit pollution and urban runoff are themselves very water-demanding. Successful green
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The Mediterranean basin is extremely vulnerable to climate change, and one of the areas most impacted by human water demand. Yet the green roofs increasingly created both for aesthetic reasons and to limit pollution and urban runoff are themselves very water-demanding. Successful green roof installation depends on the establishment of the vegetation, and the substrate is the key element: it conserves water, and provides the nutrients and physical support indispensable for plant growth. Since typical Mediterranean plant communities require no maintenance, this study seeks to develop techniques for creating maintenance- and watering-free horizontal green roofs for public or private buildings in a Mediterranean context. The innovative aspect of this study lies in creating two soil mixes, fine elements (clay and silt) and coarse elements (pebbles of all sizes), in two different thicknesses, to assess vegetation development. Monitoring of substrate moisture was carried out and coupled with local rainfall measurements during summer and autumn. As expected, substrate moisture is mainly influenced by substrate depth (the deeper, the moister) and composition (the finer the particles (clays and silts), the higher the moisture content). Vegetation cover impacts moisture to a lesser extent but is itself affected by the composition and depth of the substrates. These results are subsequently discussed with relation to the issue of sustainable green roofs in Mediterranean climates. Considering applications of our results, for an optimal colonization of a Mediterranean vegetation, a substrate thickness of 15 cm composed mainly of fine elements (75% clay-silt and 25% pebble-sand) would be recommended in green roofs. Full article
(This article belongs to the Special Issue Hydrological Performance of Green Roofs)
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Open AccessArticle Performance of Denitrifying Phosphate Removal via Nitrite from Slaughterhouse Wastewater Treatment at Low Temperature
Water 2017, 9(11), 818; doi:10.3390/w9110818
Received: 22 August 2017 / Revised: 19 October 2017 / Accepted: 19 October 2017 / Published: 31 October 2017
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Abstract
This study aims to investigate the effects of the organic loading rate (OLR) and the aeration rate on denitrifying phosphate removal (DPR) from slaughterhouse wastewater treated at a temperature of 11 °C. Three laboratory-scale intermittently aerated sequencing batch reactors (IASBRs) were set up
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This study aims to investigate the effects of the organic loading rate (OLR) and the aeration rate on denitrifying phosphate removal (DPR) from slaughterhouse wastewater treated at a temperature of 11 °C. Three laboratory-scale intermittently aerated sequencing batch reactors (IASBRs) were set up and three OLRs and five aeration rates were employed in the study. The results indicated that efficient removals of nitrogen (N) and phosphorus (P) from DPR were achieved. Furthermore, the intermittent aeration pattern benefitted both the phosphorus-accumulating organisms (PAOs) and the denitrifying phosphorus-accumulating organisms (DPAOs) that accumulated at 11 °C. The ratio of P uptake in the aeration periods/P release in the non-aeration periods was in the range of 0.94–1.10 in the three stages. The relationship between the specific poly-β-hydroxybutyrate (PHB) degradation rate (z), the specific P removal rate (x), and the specific total oxidized nitrogen(TON) reduction rate (y) can be fitted approximately as a plane ( z = 1.3626 x + 0.2882 y 0.6722 , R2 = 0.83). Full article
(This article belongs to the Special Issue Biological Treatment of Wastewater)
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Open AccessArticle Spatial and Temporal Dynamics of Potentially Toxic Cyanobacteria in the Riverine Region of a Temperate Estuarine System Altered by Weirs
Water 2017, 9(11), 819; doi:10.3390/w9110819
Received: 19 July 2017 / Revised: 4 September 2017 / Accepted: 19 October 2017 / Published: 25 October 2017
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Abstract
The effects of weirs on fish and other biological communities have garnered considerable study, whereas the effects of weirs on community composition of toxic cyanobacteria have not yet been well documented. In this study, temporal and spatial variations in species composition and the
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The effects of weirs on fish and other biological communities have garnered considerable study, whereas the effects of weirs on community composition of toxic cyanobacteria have not yet been well documented. In this study, temporal and spatial variations in species composition and the abundance of potentially toxic cyanobacteria were investigated in the riverine regions of the temperate Youngsan River estuary, where two weirs have recently been constructed. Four stations were sampled 0.5 m below the surface monthly along the channel of the upper river from May 2014 to April 2015 to explore cyanobacterial composition and abundance, while physicochemical and biological parameters were measured to elucidate possible mechanisms controlling these dynamics. Two stations were located upstream at free-flowing sites, and the other stations were located downstream at impounded sites near the weirs. Twenty-eight cyanobacterial species were identified, seven of which were potentially toxic: Microcystis sp., M. aeruginosa, M. flos-aquae, Dolichospermum sp., Aphanocapsa sp., Oscillatoria sp. and Phormidium sp. Microcystis sp. was the most abundant in June 2014 at the lowest station near the weir. Meanwhile, Phormidium sp. occurred at low abundance throughout the study period, except during the winter months, when its abundance was elevated. The interactive forward selection method highlighted dissolved inorganic nitrogen and zooplankton abundance as explanatory variables for this observed variation, but their effects on cyanobacterial growth are unclear. However, temperature was the major determinant for the temporal variation in cyanobacterial populations. Cluster analysis showed that the downstream stations near the weirs had a high similarity of potentially toxic cyanobacteria. Significantly higher abundance, especially of Microcystis sp., was also recorded at the impounded sites suggesting that the presence of weirs might affect variations in toxic cyanobacterial communities. Full article
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Open AccessArticle Robust Meter Network for Water Distribution Pipe Burst Detection
Water 2017, 9(11), 820; doi:10.3390/w9110820
Received: 15 September 2017 / Revised: 23 October 2017 / Accepted: 24 October 2017 / Published: 26 October 2017
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Abstract
A meter network is a set of meters installed throughout a water distribution system to measure system variables, such as the pipe flow rate and pressure. In the current hyper-connected world, meter networks are being exposed to meter failure conditions, such as malfunction
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A meter network is a set of meters installed throughout a water distribution system to measure system variables, such as the pipe flow rate and pressure. In the current hyper-connected world, meter networks are being exposed to meter failure conditions, such as malfunction of the meter’s physical system and communication system failure. Therefore, a meter network’s robustness should be secured for reliable provision of informative meter data. This paper introduces a multi-objective optimal meter placement model that maximizes the detection probability, minimizes false alarms, and maximizes the robustness of a meter network given a predefined number of meters. A meter network’s robustness is defined as its ability to consistently provide quality data in the event of meter failure. Based on a single-meter failure simulation, a robustness indicator for the meter network is introduced and maximized as the third objective of the proposed model. The proposed model was applied to the Austin network to determine the independent placement of pipe flow and pressure meters with three or five available meters. The results showed that the proposed model is a useful tool for determining meter locations to secure high detectability and robustness. Full article
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Open AccessArticle Combining Econometric, Cost–Benefit, and Financial Methodologies in a Framework to Increase Diffusion and to Predict the Feasibility and Sustainability of Irrigation Schemes: A Case Study in Kurdistan, Iraq
Water 2017, 9(11), 821; doi:10.3390/w9110821
Received: 27 July 2017 / Revised: 4 October 2017 / Accepted: 20 October 2017 / Published: 26 October 2017
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Abstract
This paper applies ex ante econometric, cost–benefit, and financial methodologies to increase participation in an irrigation project and predict its financial feasibility and social sustainability in Shahrazoor, Kurdistan, Iraq. I investigated the socio-economic, psycho-cultural, and financial factors that determine participation. The socio-economic part
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This paper applies ex ante econometric, cost–benefit, and financial methodologies to increase participation in an irrigation project and predict its financial feasibility and social sustainability in Shahrazoor, Kurdistan, Iraq. I investigated the socio-economic, psycho-cultural, and financial factors that determine participation. The socio-economic part of the econometric analysis showed that the project was appreciated more by poorer and economically weaker farmers who rely on agriculture than by those who rely on livestock activities. The psycho-cultural part of the econometric analysis emphasized that the project was appreciated more by literate farmers who adopt a maximization (rather than habit) approach. The cost–benefit analysis applied to the irrigation project was tailored to poorer and weaker farmers (i.e., costs of the irrigation scheme and benefits from new cultivation patterns were defined with reference to small farms) by including indirect benefits from both irrigation (e.g., flood control) and hydropower (e.g., eliminated GHG emissions), and determined a 7.1% mean internal rate of return; this was affected more strongly by uncertainty in crop prices than by uncertainty in indirect benefits. The financial analysis highlighted values for water prices, financial returns, and loan rates that met government and farmer budgets. A single framework summarized the main relevant social, economic, and financial conditions, and, by including insights from sensitivity analyses, determined the feasibility and sustainability of the irrigation project. Provided that the water price charged to farmers is between 0.32 and 0.57 USD/m3, and the loan interest rate paid by farmers is smaller than 3.0%, the irrigation project in Shahrazoor is financially feasible for 13.6% of all reliable economic solutions and socially sustainable for 35.8% of the solutions. Full article
(This article belongs to the collection Water Policy Collection)
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Open AccessArticle Participatory Irrigation Management and Irrigation Water Use Efficiency in Maize Production: Evidence from Zhangye City, Northwestern China
Water 2017, 9(11), 822; doi:10.3390/w9110822
Received: 28 September 2017 / Revised: 15 October 2017 / Accepted: 23 October 2017 / Published: 30 October 2017
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Abstract
Water has become increasingly scarce in northwestern China due to climate change, economic growth and burgeoning population. Improving agriculture water use efficiency is of strategic significance in promoting socio-economic water productivity for arid and semi-arid inland river basins. Based on the household-level data
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Water has become increasingly scarce in northwestern China due to climate change, economic growth and burgeoning population. Improving agriculture water use efficiency is of strategic significance in promoting socio-economic water productivity for arid and semi-arid inland river basins. Based on the household-level data collected in Zhangye City, which is located in the middle reaches of Heihe River Basin (HRB) in northwestern China, irrigation water use efficiency (IWUE) of maize is estimated based on stochastic frontier analysis. The impacts of influential factors, especially the participatory irrigation management (PIM) through water user associations (WUAs), on IWUE were further examined. Results show that the estimated average Technical efficiency (TE) and IWUE of maize production are 0.74 and 0.24, respectively. The participation level in irrigation management is very low, with only 40% of the respondents participating in WUA meetings. In addition, most have a relatively superficial understanding of the roles and management scheme of WUAs. Empirical results show that though significantly positive, the magnitude of the impact of PIM on IWUE is relatively small. Households that participated in WUA meetings achieved only 0.002% higher IWUEs than those have never participated in. WUAs are not operating with their designed objectives. Consequently, reform of the traditional management form of WUAs to make them more transparent, fair, and extensively participated in among farmers is in urgently need. In addition, we also find that water price, source of irrigation water, irrigation technology adoption and famers’ education level and farming experience also have significant positive impacts on IWUE. Full article
(This article belongs to the Special Issue Sustainable Water Management within Inland River Watershed)
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Open AccessArticle The Spatiotemporal Distribution of Two Bacterial Indexes in a Small Tibetan Plateau Watershed
Water 2017, 9(11), 823; doi:10.3390/w9110823
Received: 18 September 2017 / Revised: 23 October 2017 / Accepted: 25 October 2017 / Published: 30 October 2017
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Abstract
Microbial contamination is now more common than chemical contamination in Tibet, and water-borne microbes can cause a number of diseases that threaten public health. Thus, in order to clarify the spatiotemporal distribution of bacteria in small watersheds for which there is no data
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Microbial contamination is now more common than chemical contamination in Tibet, and water-borne microbes can cause a number of diseases that threaten public health. Thus, in order to clarify the spatiotemporal distribution of bacteria in small watersheds for which there is no data in Tibet, four sampling points were set up along an upstream-downstream transect of the Xincang River Basin. A total of 239 water samples were collected in 2014 and 2015, and their total constituent numbers of bacteria (TB) and coliforms (TC) were evaluated. The results of this study show that the microbial contamination of the Xincang River Basin is mild-to-moderate in terms of TB and TC contents, and that these concentrations vary significantly in different seasons. The results show that in summer, TB and TC concentrations and microbial contamination are almost at the same level in upstream, midstream, and downstream sections; however, in the other three seasons, microbial contamination in the downstream section is more serious than in the upstream and midstream sections. The data also demonstrates that concentrated precipitation and local contamination sources are important factors underlying increases in TB and TC concentrations during the summer months. The results of this study are likely to reflect the basic characteristics of small watersheds for which there is no data to some extent, and are thus of significant practical importance for protecting their ecological environments and promoting sustainable development. Full article
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Open AccessArticle Assessment of Water Quality Improvements Using the Hydrodynamic Simulation Approach in Regulated Cascade Reservoirs: A Case Study of Drinking Water Sources of Shenzhen, China
Water 2017, 9(11), 825; doi:10.3390/w9110825
Received: 7 July 2017 / Revised: 23 October 2017 / Accepted: 24 October 2017 / Published: 27 October 2017
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Abstract
Water quality safety is of critical importance in environmental improvement, particularly with respect to drinking water resources worldwide. As the main drinking water sources in Shenzhen, China, the cascade reservoirs comprising the Shiyan, Tiegang, and Xili Reservoirs are highly regulated and have experienced
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Water quality safety is of critical importance in environmental improvement, particularly with respect to drinking water resources worldwide. As the main drinking water sources in Shenzhen, China, the cascade reservoirs comprising the Shiyan, Tiegang, and Xili Reservoirs are highly regulated and have experienced water quality deterioration in recent years. In this study, a three-dimensional hydrodynamic and water quality model was established using the Environmental Fluid Dynamics Code (EFDC) for the cascade reservoirs. The relationships between water quality and improvement measures were quantified and the main pollution sources for individual reservoirs were identified. Results showed that the hydrodynamic and water quality model well captured the spatial and temporal variations of water level, the permanganate concentration index (CODMn), and total nitrogen (TN), with high resolution in the cascade reservoirs. The correlation coefficients between simulations and observations were close to 1.00 for water levels, and over 0.50 for CODMn and TN concentrations. The most effective methods for water quality improvement were the reduction of the runoff load for TN and transferred water load for CODMn in the Shiyan Reservoir, reduction of the transferred water load in the Tiegang Reservoir, and an increase in transfer water volume, especially in the flood season, in the Xili Reservoir. Internal pollution sources also played an important role in water pollution, and thus sedimentation should be cleaned up regularly. This study is expected to provide scientific support for drinking water source protection and promote the application of hydrodynamic model in water quality management. Full article
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Open AccessArticle Effects of Plant Growth Form and Water Substrates on the Decomposition of Submerged Litter: Evidence of Constructed Wetland Plants in a Greenhouse Experiment
Water 2017, 9(11), 827; doi:10.3390/w9110827
Received: 25 August 2017 / Revised: 20 October 2017 / Accepted: 20 October 2017 / Published: 27 October 2017
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Abstract
Wetland plants are important components in constructed wetlands (CWs), and one of their most important functions in CWs is to purify the water. However, wetland plant litter can also increase eutrophication of water via decomposition and nutrient release, and few studies have focused
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Wetland plants are important components in constructed wetlands (CWs), and one of their most important functions in CWs is to purify the water. However, wetland plant litter can also increase eutrophication of water via decomposition and nutrient release, and few studies have focused on the interspecific variation in the decomposition rate and nutrient release of multiple plant species in CWs. Here a greenhouse litter-bag experiment was conducted to quantify the decomposition rates and nutrient release of 7 dominant macrophytes (2 floating plants and 5 emergent plants) in three types of water substrate. The results showed that plant litter species and growth forms significantly affected the litter mass losses. The nutrient release was significantly different among plant litter species, but not between floating and emergent plants. Litter traits, such as litter lignin, total nitrogen (TN) and total phosphorus (TP) can well predict the decomposition rates of submerged litter. These results indicated that submerging litter in water did not change the relationships between litter traits and litter decomposition rates, and leaching might play a more important role in the decomposition of submerged litter in CWs than that in other terrestrial ecosystems. These findings can provide suggestions for managers about the maintenance of constructed wetlands. Full article
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Open AccessArticle A Theoretical Model to Predict the Critical Hydraulic Gradient for Soil Particle Movement under Two-Dimensional Seepage Flow
Water 2017, 9(11), 828; doi:10.3390/w9110828
Received: 7 October 2017 / Revised: 24 October 2017 / Accepted: 26 October 2017 / Published: 29 October 2017
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Abstract
The soil particle movement under seepage flow is one of the predominant mechanisms responsible for incidents and failures of dams and streambanks. However, little attention has been paid to the critical hydraulic gradient under two-dimensional (2-D) seepage flow. In this study, a theoretical
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The soil particle movement under seepage flow is one of the predominant mechanisms responsible for incidents and failures of dams and streambanks. However, little attention has been paid to the critical hydraulic gradient under two-dimensional (2-D) seepage flow. In this study, a theoretical model was established under 2-D seepage flow to predict the critical hydraulic gradients for soil particle movement. In this model, the sediment particle rolling theory was used, while taking into account the relative exposure degree of the soil grains and the seepage direction. The model was validated through qualitative analysis and comparison with previous data, and showed considerable superiority over Terzaghi's model. In addition, the effect of the soil internal instability, implying that the critical hydraulic gradient of unstable soil is lower than that of stable soil, was discussed. Various parameters of the model were also analyzed. The results showed that the seepage direction angle was positively related to the critical gradient, whereas the void and the mean diameter of the soil were negatively related to it. Finally, the model proposes a calculation method for the particle movement initiation probability, which is regarded as a key parameter in the sediment transport model. Full article
(This article belongs to the Special Issue Streambank Erosion: Monitoring, Modeling and Management)
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Open AccessArticle Characterization of a Microbial Community in an Anammox Process Using Stored Anammox Sludge
Water 2017, 9(11), 829; doi:10.3390/w9110829
Received: 8 September 2017 / Revised: 30 September 2017 / Accepted: 27 October 2017 / Published: 29 October 2017
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Abstract
This study investigated a rapid start-up anaerobic ammonium oxidation (Anammox) process by inoculation with stored Anammox sludge and characterized the associated microbial communities. The Anammox process took only 43 days to start. A high nitrogen removal rate of 1.13 kg N m−3
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This study investigated a rapid start-up anaerobic ammonium oxidation (Anammox) process by inoculation with stored Anammox sludge and characterized the associated microbial communities. The Anammox process took only 43 days to start. A high nitrogen removal rate of 1.13 kg N m−3 d−1 and a nitrogen loading rate of 1.28 kg N m−3 d−1 were achieved. The ratio of ammonium removal to nitrite removal to nitrate production (1:1:0.2) was slightly lower than the theoretical value, which indicated nitrogen removal by denitrification in the reactor. Illumina high-throughput sequencing of sludge samples confirmed the co-existence of Anammox bacteria and denitrifying bacteria in the reactor and demonstrated that denitrifying bacteria play a role in nitrogen removal during the Anammox process. The dominant microbes in the reactor were Proteobacteria, Chlorobi, Chloroflexi, and Planctomycetes. However, only one species of Anammox bacteria, Candidatus jettenia, was identified and had an abundance of 4.92%. Our results illustrate the relationship between Anammox reactor performance and microbial community succession. Full article
(This article belongs to the Special Issue Biological Treatment of Wastewater)
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Open AccessArticle Water Management Reporting in the Agro-Food Sector in South Africa
Water 2017, 9(11), 830; doi:10.3390/w9110830
Received: 24 June 2017 / Revised: 26 October 2017 / Accepted: 27 October 2017 / Published: 29 October 2017
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Abstract
The purpose of the study is to assess whether Corporate Social Responsibility regarding water is considered relevant for sustainability in companies related to agriculture in South Africa, considering that their impact directly influences public access to water. To accomplish this purpose, a qualitative
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The purpose of the study is to assess whether Corporate Social Responsibility regarding water is considered relevant for sustainability in companies related to agriculture in South Africa, considering that their impact directly influences public access to water. To accomplish this purpose, a qualitative approach was developed through the study of the 22 existing companies from the agriculture sector, food and beverages, forest and paper production, and Tobacco, which published their last integrated report within the Global Reporting Initiative framework. A thematic content analysis was carried out, involving the analysis of the written sustainability reports. For data analyses, ATLAS.ti 7.1 software was used to match the main aspects related to water management. Pragmatic advice for practitioners derives from the research results, considering that Corporate Social Responsibility in general—and sustainable water management in particular—represents an opportunity for companies to get competitive advantages in the market. The study also determines the best practices in the field in South Africa with benchmarking purposes. Full article
(This article belongs to the collection Water Policy Collection)
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Open AccessArticle Informing National Food and Water Security Policy through Water Footprint Assessment: the Case of Iran
Water 2017, 9(11), 831; doi:10.3390/w9110831
Received: 9 September 2017 / Revised: 19 October 2017 / Accepted: 23 October 2017 / Published: 29 October 2017
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Abstract
Iran’s focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water
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Iran’s focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water consumption in relation to food production, consumption, and trade, we carried out the first comprehensive water footprint assessment (WFA) for Iran, for the period 1980–2010, and estimated the water saving per province associated with interprovincial and international crop trade. Based on the AquaCrop model, we estimated the green and blue water footprint (WF) related to both the production and consumption of 26 crops, per year and on a daily basis, for 30 provinces of Iran. We find that, in the period 1980–2010, crop production increased by 175%, the total WF of crop production by 122%, and the blue WF by 20%. The national population grew by 92%, and the crop consumption per capita by 20%, resulting in a 130% increase in total food consumption and a 110% increase in the total WF of national crop consumption. In 2010, 26% of the total water consumption in the semi-arid region served the production of crops for export to other regions within Iran (mainly cereals) or abroad (mainly fruits and nuts). Iran’s interprovincial virtual water trade grew by a factor of 1.6, which was mainly due to increased interprovincial trade in cereals, nuts, and fruits. Current Iranian food and water policy could be enriched by reducing the WFs of crop production to certain benchmark levels per crop and climatic region and aligning cropping patterns to spatial differences in water availability and productivities, and by paying due attention to the increasing food consumption per capita in Iran. Full article
(This article belongs to the Special Issue Progress in Water Footprint Assessment)
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Open AccessArticle Analysis of Dynamic Spatiotemporal Changes in Actual Evapotranspiration and Its Associated Factors in the Pearl River Basin Based on MOD16
Water 2017, 9(11), 832; doi:10.3390/w9110832
Received: 28 September 2017 / Revised: 19 October 2017 / Accepted: 27 October 2017 / Published: 1 November 2017
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Abstract
Evapotranspiration is an important part of the hydrological cycle, surface energy balance and global climate system. Due to spatial heterogeneity, the trends in actual evapotranspiration (ET) and its associated factors vary in different regions. Because direct measurements of ET are limited over large
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Evapotranspiration is an important part of the hydrological cycle, surface energy balance and global climate system. Due to spatial heterogeneity, the trends in actual evapotranspiration (ET) and its associated factors vary in different regions. Because direct measurements of ET are limited over large areas, remote sensing provides an efficient method of ET spatial analysis, and standard data products are available at the global scale. This study uses the monthly MOD16 ET dataset and daily meteorological data to analyze the dynamic spatiotemporal changes in ET and its associated factors in the Pearl River Basin (PRB) from 2000 to 2014. The results of the study are as follows. (1) Over time and space, annual ET exhibited a slight increasing trend from 2000 to 2014, with an average value of approximately 946.56 mm/a. ET considerably varied at the monthly and seasonal scales, and in July displayed the highest monthly ET of approximately 119.57 mm, accounting for 36.37% of the annual ET. (2) ET displayed obvious spatial heterogeneity. Specifically, the west was a low-ET region, and moderate and high ET values were interspersed in the central and eastern PRB. Moreover, the rate of change of ET ranged from −13.99 mm/a to 12.81 mm/a in space, and 46.25% of the basin exhibited an increasing trend. (3) Dynamic changes in ET were mainly associated with temperature and relative humidity (RH). Additionally, energy-related elements and wind speed were positively correlated with ET, and temperature was the most influential factor of ET in some months (February–March and September–November). RH was the most important factor in other months but negatively correlated with ET in June and July. Affected by the actual environmental condition, qualitative changes were observed in the correlation between RH and ET in different months. The positive and negative spatial correlations between ET and its associated factors changed in different regions and in different months, and the changes mainly occurred from northwest to southwest. Full article
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Open AccessArticle Diversity and Distribution of Endemic Stream Insects on a Nationwide Scale, South Korea: Conservation Perspectives
Water 2017, 9(11), 833; doi:10.3390/w9110833
Received: 30 September 2017 / Revised: 21 October 2017 / Accepted: 24 October 2017 / Published: 30 October 2017
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Abstract
This study aimed to identify the biogeographical and environmental factors affecting the biodiversity of endemic aquatic species (i.e., Ephemeroptera, Plecoptera and Trichoptera; EPT). We used data collected from 714 sampling sites combined with 39 environmental factors. Ten EPT endemic species were identified. The
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This study aimed to identify the biogeographical and environmental factors affecting the biodiversity of endemic aquatic species (i.e., Ephemeroptera, Plecoptera and Trichoptera; EPT). We used data collected from 714 sampling sites combined with 39 environmental factors. Ten EPT endemic species were identified. The sampling sites grouped into four clusters based on the similarities of the endemic EPT assemblages using a hierarchical cluster analysis. Non-metric multidimensional scaling (NMS) revealed the differences among the four clusters, with the first three axes being strongly related to annual average, August, and January temperatures, as well as altitude. The random forest model identified geological and meteorological factors as the main factors influencing species distribution, even though the contributions of environmental factors were species-specific. Species with the lower occurrence frequency (i.e., Pteronarcys macra, Kamimuria coreana, and Psilotreta locumtenens) mainly occurred in the least-disturbed habitats. P. macra represents a priority conservation species, because it has a limited distribution range and is highly vulnerable to anthropogenic disturbance. Our results support the need for an environmental management policy to regulate deforestation and conserve biodiversity, including endemic species. Full article
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Open AccessArticle Spatial Downscaling of Suomi NPP–VIIRS Image for Lake Mapping
Water 2017, 9(11), 834; doi:10.3390/w9110834
Received: 29 July 2017 / Revised: 26 October 2017 / Accepted: 27 October 2017 / Published: 30 October 2017
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Abstract
Capturing the dynamics of a lake-water area using remotely sensed images has always been an essential task. Most of the fine spatial resolution data are unsuitable for this purpose because of their low temporal resolution and limited scene coverage. A Visible Infrared Imaging
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Capturing the dynamics of a lake-water area using remotely sensed images has always been an essential task. Most of the fine spatial resolution data are unsuitable for this purpose because of their low temporal resolution and limited scene coverage. A Visible Infrared Imaging Radiometer Suite on board the Suomi National Polar-orbiting Partnership (Suomi NPP–VIIRS) is a newly-available and appropriate sensor for monitoring large lakes due to its frequent revisits and wide swath (more than 3000 km). However, it provides visible and infrared images at relatively coarse spatial resolutions, which would sometimes hamper the accurate mapping of lake shorelines. This study, therefore, proposes a two-step downscaling method that combines spectral unmixing and subpixel mapping to produce a finer resolution lake map from NPP–VIIRS imagery, which is then applied to delineate the shorelines of five plateau lakes in Yunnan Province, as well as the shoreline dynamics of Poyang Lake at three separate times. A newly published global water dynamic dataset is employed in this study to improve the downscaling method. Results suggest that the proposed method can generate a finer resolution lake map that exhibits more details of the shoreline than hard classification. The downscaling results of the Suomi NPP–VIIRS generally achieve higher than 75% accuracy, while the downscaling results of a Landsat-simulated fraction map could have accuracy higher than 85%. This reveals that errors and uncertainties exist in both procedures, but mainly come from the spectral unmixing procedure which retrieves water fractions from NPP–VIIRS data. Full article
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Open AccessArticle Heterotrophic Nitrification-Aerobic Denitrification Performance of Strain Y-12 under Low Temperature and High Concentration of Inorganic Nitrogen Conditions
Water 2017, 9(11), 835; doi:10.3390/w9110835
Received: 12 September 2017 / Revised: 15 October 2017 / Accepted: 27 October 2017 / Published: 30 October 2017
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Abstract
An aerobic nitrite-denitrifying bacterium Pseudomonas putida Y-12 was used to remove sole and mixed nitrogen sources at 15 °C. When strain Y-12 was incubated for 4 days with a sole nitrogen source and initial NH4+-N, NO3-N, and
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An aerobic nitrite-denitrifying bacterium Pseudomonas putida Y-12 was used to remove sole and mixed nitrogen sources at 15 °C. When strain Y-12 was incubated for 4 days with a sole nitrogen source and initial NH4+-N, NO3-N, and NO2-N concentrations of 208.1, 204.7, and 199.0 mg/L, respectively, the removal ratios of NH4+-N, NO3-N, and NO2-N were 98.8, 73.6, and 77.1%, respectively. The average removal rates of NH4+-N, NO3-N, and NO2-N reached 2.14, 1.57, and 1.60 mg/L/h, respectively. Intermediate products (NO3-N and NO2-N) were detected at a low level. Total nitrogen removal was mainly achieved during the stationary phase in the denitrification process. All the results indicated that strain Y-12 could perform heterotrophic nitrification and aerobic denitrification at 15 °C, which was beneficial for future applications in wastewater treatment at low temperatures. Full article
(This article belongs to the Special Issue Biological Treatment of Wastewater)
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Open AccessArticle Effective Use of Ensemble Numerical Weather Predictions in Taiwan by Means of a SOM-Based Cluster Analysis Technique
Water 2017, 9(11), 836; doi:10.3390/w9110836
Received: 29 August 2017 / Revised: 6 October 2017 / Accepted: 25 October 2017 / Published: 30 October 2017
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Abstract
Typhoon rainfall is one of the most important water resources in Taiwan. However, heavy rainfall during typhoons often leads to serious disasters. Therefore, accurate typhoon rainfall forecasts are always desired for water resources managers and disaster warning systems. In this study, the quantitative
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Typhoon rainfall is one of the most important water resources in Taiwan. However, heavy rainfall during typhoons often leads to serious disasters. Therefore, accurate typhoon rainfall forecasts are always desired for water resources managers and disaster warning systems. In this study, the quantitative rainfall forecasts from an ensemble numerical weather prediction system in Taiwan are used. Furthermore, a novel strategy, which is based on the use of a self-organizing map (SOM) based cluster analysis technique, is proposed to integrate these ensemble forecasts. By means of the SOM-based cluster analysis technique, ensemble forecasts that have similar features are clustered. That is helpful for users to effectively combine these ensemble forecasts for providing better typhoon rainfall forecasts. To clearly demonstrate the advantage of the proposed strategy, actual application is conducted during five typhoon events. The results indicate that the ensemble rainfall forecasts from numerical weather prediction models are well categorized by the SOM-based cluster analysis technique. Moreover, the integrated typhoon rainfall forecasts resulting from the proposed strategy are more accurate when compared to those from the conventional method (i.e., the ensemble mean of all forecasts). In conclusion, the proposed strategy provides improved forecasts of typhoon rainfall. The improved quantitative rainfall forecasts are expected to be useful to support disaster warning systems as well as water resources management systems during typhoons. Full article
(This article belongs to the Special Issue Impact of Climate on Hydrological Extremes)
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Open AccessArticle Assessing the Viability of Sub-Surface Drip Irrigation for Resource-Efficient Alfalfa Production in Central and Southern California
Water 2017, 9(11), 837; doi:10.3390/w9110837
Received: 9 August 2017 / Revised: 12 October 2017 / Accepted: 18 October 2017 / Published: 30 October 2017
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Abstract
In California, alfalfa is grown on a large area ranging between 325,000 and 410,000 hectares and ranks among the thirstiest crops. While the hay production industry is often scrutinized for the large usage of the state’s agricultural water, alfalfa is a crucial feed-supplier
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In California, alfalfa is grown on a large area ranging between 325,000 and 410,000 hectares and ranks among the thirstiest crops. While the hay production industry is often scrutinized for the large usage of the state’s agricultural water, alfalfa is a crucial feed-supplier for the livestock and dairy sectors, which rank among the most profitable commodity groups in the state. Sub-surface drip irrigation (SDI), although only practiced on approximately 2% of the alfalfa production area in California, is claimed to have the potential to significantly increase hay yield (HY) and water productivity (WP) compared with surface irrigation (SI). In 2014–2016 we interviewed a number of growers pioneering SDI for alfalfa production in Central and Southern California who reported that yield improvements in the order of 10–30% and water saving of about 20–30% are achievable in SDI-irrigated fields compared with SI, according to their records and perceptions collected over few years of experience. Results from our research on SDI at the University of California, Davis, revealed significantly smaller yield gain (~5%) and a slight increase of water use (~2–3%) that are similar to findings from earlier research studies. We found that most of the interviewed alfalfa producers are generally satisfied with their SDI systems, yet face some challenges that call for additional research and educational efforts. Key limitations of SDI include high investment costs, use of energy to pressurize water, the need for more advanced irrigation management skills, and better understanding of soil-water dynamics by farm personnel. SDI-irrigated fields also need accurate water monitoring and control, attentive prevention and repair of rodent damages, and careful salinity management in the root zone. In this paper we attempt to evaluate the viability of the SDI technology for alfalfa production on the basis of preliminary results of our research and extension activities, with focus on its water and energy footprints within the context of resource efficiency. Full article
(This article belongs to the Special Issue Resilient Water Management in Agriculture)
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Open AccessArticle Performance Assessment of Spatial Interpolation of Precipitation for Hydrological Process Simulation in the Three Gorges Basin
Water 2017, 9(11), 838; doi:10.3390/w9110838
Received: 13 August 2017 / Revised: 25 October 2017 / Accepted: 27 October 2017 / Published: 1 November 2017
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Abstract
Accurate assessment of spatial and temporal precipitation is crucial for simulating hydrological processes in basins, but is challenging due to insufficient rain gauges. Our study aims to analyze different precipitation interpolation schemes and their performances in runoff simulation during light and heavy rain
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Accurate assessment of spatial and temporal precipitation is crucial for simulating hydrological processes in basins, but is challenging due to insufficient rain gauges. Our study aims to analyze different precipitation interpolation schemes and their performances in runoff simulation during light and heavy rain periods. In particular, combinations of different interpolation estimates are explored and their performances in runoff simulation are discussed. The study was carried out in the Pengxi River basin of the Three Gorges Basin. Precipitation data from 16 rain gauges were interpolated using the Thiessen Polygon (TP), Inverse Distance Weighted (IDW), and Co-Kriging (CK) methods. Results showed that streamflow predictions employing CK inputs demonstrated the best performance in the whole process, in terms of the Nash–Sutcliffe Coefficient (NSE), the coefficient of determination (R2), and the Root Mean Square Error (RMSE) indices. The TP, IDW, and CK methods showed good performance in the heavy rain period but poor performance in the light rain period compared with the default method (least sophisticated nearest neighbor technique) in Soil and Water Assessment Tool (SWAT). Furthermore, the correlation between the dynamic weight of one method and its performance during runoff simulation followed a parabolic function. The combination of CK and TP achieved a better performance in decreasing the largest and lowest absolute errors compared to any single method, but the IDW method outperformed all methods in terms of the median absolute error. However, it is clear from our findings that interpolation methods should be chosen depending on the amount of precipitation, adaptability of the method, and accuracy of the estimate in different rain periods. Full article
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Open AccessArticle A Commune-Level Groundwater Potential Map for the Republic of Mali
Water 2017, 9(11), 839; doi:10.3390/w9110839
Received: 3 August 2017 / Revised: 26 October 2017 / Accepted: 27 October 2017 / Published: 31 October 2017
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Abstract
Groundwater represents an essential resource in sub-Saharan Africa, where several hundred million people rely on aquifers for domestic supply. This paper presents a method to map groundwater potential in the Republic of Mali based on a spatially-distributed database of 26,040 boreholes. The database
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Groundwater represents an essential resource in sub-Saharan Africa, where several hundred million people rely on aquifers for domestic supply. This paper presents a method to map groundwater potential in the Republic of Mali based on a spatially-distributed database of 26,040 boreholes. The database includes exhaustive information on key parameters such as borehole location, success rate of borehole production, depth, yield, static groundwater level or water quality. Representative variables were classified and interpreted jointly to develop a groundwater potential index for each of the 703 communes in Mali. This provides a methodological novelty because groundwater potential studies typically rely on indirect indicators such as lineaments, slope, soil moisture and landforms. Also, such large borehole databases have seldom been used to estimate groundwater potential. The highest indexes were obtained for the areas in and around the River Niger’s Inner Delta, including southern Tombouctou and the central parts of the Ségou and Mopti Regions. The lower Precambrian formations, which include the country’s thoroughly populated southern plateau, had moderate scores. The lowest groundwater potential was found in the northern part of the Kayes and Koulikoro Regions, as well as in the entire region of Kidal. By providing results at the commune scale, these outcomes show that groundwater potential across the country’s geological and hydrogeological units can be highly variable, and that local and regional-scale information may be useful for groundwater management purposes. These results are policy-relevant in a context of rapid change and population growth, where groundwater resources can be expected to be increasingly relied upon in the coming years. Full article
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Open AccessArticle Study on Storm-Water Management of Grassed Swales and Permeable Pavement Based on SWMM
Water 2017, 9(11), 840; doi:10.3390/w9110840
Received: 28 September 2017 / Revised: 17 October 2017 / Accepted: 26 October 2017 / Published: 31 October 2017
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Abstract
Grassed swales and permeable pavement that have greater permeable underlying surface relative to hard-pressing surface can cooperate with the city pipe network on participating in urban storm flood regulation. This paper took Nanshan village in Jiangsu Province as an example, the storm-water management
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Grassed swales and permeable pavement that have greater permeable underlying surface relative to hard-pressing surface can cooperate with the city pipe network on participating in urban storm flood regulation. This paper took Nanshan village in Jiangsu Province as an example, the storm-water management model (SWMM) was used to conceptualize the study area reasonably, and the low-impact development (LID) model and the traditional development model were established in the region. Based on the storm-intensity equation, the simulation scene employed the Chicago hydrograph model to synthesize different rainfall scenes with different rainfall repetition periods, and then contrasted the storm-flood-management effect of the two models under the condition of using LID facilities. The results showed that when the rainfall repetition period ranged from 0.33a to 10a (a refers to the rainfall repetition period), the reduction rate of total runoff in the research area that adopted LID ranged from 100% to 27.5%, while the reduction rate of peak flow ranged from 100% to 15.9%, and when the values of unit area were the same, the combined system (permeable pavement + grassed swales) worked more efficiently than the sum of the individuals in the reduction of total runoff and peak flow throughout. This research can provide technical support and theoretical basis for urban LID design. Full article
(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)
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Open AccessArticle Enhancing the Economic Value of Large Investments in Sustainable Drainage Systems (SuDS) through Inclusion of Ecosystems Services Benefits
Water 2017, 9(11), 841; doi:10.3390/w9110841
Received: 13 July 2017 / Revised: 10 October 2017 / Accepted: 16 October 2017 / Published: 31 October 2017
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Abstract
Although Sustainable Drainage Systems (SuDS) are used in cities across the world as effective flood adaptation responses, their economic viability has frequently been questioned. Inclusion of the monetary value of ecosystem services (ES) provided by SuDS can increase the rate of return on
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Although Sustainable Drainage Systems (SuDS) are used in cities across the world as effective flood adaptation responses, their economic viability has frequently been questioned. Inclusion of the monetary value of ecosystem services (ES) provided by SuDS can increase the rate of return on investments made. Hence, this paper aims at reviewing the enhancement of the economic value of large-scale investments in SuDS through inclusion of ecosystem services. This study focuses on the flood reduction capacity and the ES benefits of green roofs and rain barrels in the combined sewerage network of Montevideo Municipality in Uruguay. The methodology comprises a cost–benefit analysis—with and without monetised ES provided by SuDS—of two drainage network configurations comprising: (i) SuDS; and (ii) SuDS and detention storage. The optimal drainage design for both these drainage configurations have been determined using SWMM-EA, a tool which uses multi-objective optimisation based evolutionary algorithm (EA) and the storm water management model (SWMM). In both design configurations, total benefits comprising both flood reduction and ES benefits are always higher than their costs. The use of storage along with SuDS provides greater benefits with a larger reduction in flooding, and thus is more cost-effective than using SuDS alone. The results show that, for both of the drainage configurations, the larger investments are not beneficial unless ES benefits are taken into account. Hence, it can be concluded that the inclusion of ES benefits is necessary to justify large-scale investments in SuDS. Full article
(This article belongs to the Special Issue Sponge Cities: Emerging Approaches, Challenges and Opportunities)
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Open AccessArticle Tree Shelterbelts as an Element to Improve Water Resource Management in Central Asia
Water 2017, 9(11), 842; doi:10.3390/w9110842
Received: 24 August 2017 / Revised: 15 October 2017 / Accepted: 20 October 2017 / Published: 31 October 2017
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Abstract
In Central Asia, agriculture, notably irrigated agriculture, is the largest water consumer. Currently, flood and furrow irrigation are the dominant irrigation methods in Central Asia, in particular in the post-Soviet countries. Against the background of current and increasing competition for water—e.g., through reduced
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In Central Asia, agriculture, notably irrigated agriculture, is the largest water consumer. Currently, flood and furrow irrigation are the dominant irrigation methods in Central Asia, in particular in the post-Soviet countries. Against the background of current and increasing competition for water—e.g., through reduced river runoffs in the course of climate change—water consumption of agriculture needs to be reduced. On the field plot level, improved irrigation technologies, like drip irrigation or plastic mulch, can reduce water consumption substantially. Alternatively, tree lines as wind breaks (shelterbelts) also can reduce crop water consumption, as shown by research from many drylands around the world. As previous research has concentrated on crop water consumption and not on tree water consumption, this paper brings the two together, in order to approach a more holistic picture, in how far shelterbelt systems, including the trees, may have the potential to save water or not. Crop water consumption was assessed through the Penman–Monteith approach for corn, wheat, potato, barley, and pear under open field conditions and under an assumed influence of a tree shelterbelt. Tree water consumption was investigated through sap flow measurements. Crop water consumption was reduced by 10–12% under influence of a shelterbelt compared to open field conditions. When water consumption of shelterbelts was added, a slight reduction of water consumption of the whole crop-shelterbelt system was found for corn, potato, and pear under the assumption 25 ha (500 × 500 m) field sizes. Under an assumption of 4 ha (200 × 200 m) field size, water consumption of the whole crop-shelterbelt system was higher for all crops investigated except for pear. The results suggest that shelterbelts may play a role in improving water resource management in Central Asia in the context of water demanding crops, like corn or cotton. In further research, other effects of shelterbelts, like increased crop yields and additional income from trees, need to be investigated. Full article
(This article belongs to the Special Issue The Future of Water Management in Central Asia)
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Open AccessArticle Convertible Operation Techniques for Pump Stations Sharing Centralized Reservoirs for Improving Resilience in Urban Drainage Systems
Water 2017, 9(11), 843; doi:10.3390/w9110843
Received: 9 August 2017 / Revised: 16 October 2017 / Accepted: 30 October 2017 / Published: 31 October 2017
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Abstract
Pump stations prevent backwater effects from urban streams and safely drain rainwater in urban areas. Urbanization has increased the required capacity of centralized reservoirs and drainage pumps; yet, their respective designs are based on the runoff of the target watershed at the time
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Pump stations prevent backwater effects from urban streams and safely drain rainwater in urban areas. Urbanization has increased the required capacity of centralized reservoirs and drainage pumps; yet, their respective designs are based on the runoff of the target watershed at the time of design. In Korea, additional pump stations are constructed to supplement the insufficient capacity of centralized reservoirs and drainage pumps. Two pump stations in the same drainage area share centralized reservoirs, and there are gates between them. Operation of the gates and drainage pumps is based on the water level in the connected centralized reservoirs. The convertible operation is based on changes in flow between two pump stations with different effluent streams in shared centralized reservoirs. Efficient distribution of inflow to both pump stations provides additional storage capacity in centralized reservoirs and rapid drainage. For a rainfall event in 2010, flooding volumes for current and convertible operations were 58,750 and 7507 m3, respectively. For an event in 2011, the corresponding figures were 3697 and 471 m3. This shows that resilience increased by 0.10829 and 0.00756, respectively, for the two events. Accordingly, a new technique to operate multiple pump stations for reducing urban inundation is proposed. Full article
(This article belongs to the Special Issue Urban Water Cycle Modelling and Management)
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Open AccessArticle The Impact of Demographic Factors, Beliefs, and Social Influences on Residential Water Consumption and Implications for Non-Price Policies in Urban India
Water 2017, 9(11), 844; doi:10.3390/w9110844
Received: 31 July 2017 / Revised: 11 October 2017 / Accepted: 28 October 2017 / Published: 2 November 2017
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Abstract
In rapidly growing urban areas in India and the developing world, water demands typically exceed supply. While local governments may implement management programs to reduce demand for freshwater, water savings are dependent on the conservation behaviors of individuals. A household survey is presented
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In rapidly growing urban areas in India and the developing world, water demands typically exceed supply. While local governments may implement management programs to reduce demand for freshwater, water savings are dependent on the conservation behaviors of individuals. A household survey is presented here to examine residential water end uses and conservation behaviors in Jaipur, India. The survey explores end uses, engagement in conservation behaviors, and the influence of demographic factors, water sources, beliefs about water, and social pressures on these behaviors are tested. The survey was conducted at 248 households, including 29 households in the slums. Our study finds that while the majority of participants recognize the importance of water conservation, they do not necessarily conserve water themselves. Households report engaging most frequently in water-conservation behaviors that require little effort or financial investment. Multivariate analysis of variance (MANOVA) results and subsequent pairwise comparisons indicate higher incomes, longer water-supply durations, and the belief that droughts are preventable are positively correlated with overall amenability to adoption of water-conservation behaviors and technology. Binomial logistic regression analysis indicates that being in the age group 26–35, having higher income, and giving a neutral response about the responsibility of the government to provide relief during a drought were all predictors of the installation of dual-flush (DF) toilets. Education levels and water awareness were found to have no correlation with conservation behaviors or amenability to conservation technology adoption. Results are applied to examine their possible implications from a demand-management perspective and provide suggestions for further research and policy decisions. Full article
(This article belongs to the Special Issue Advances in the Economic Analysis of Residential Water Use)
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Open AccessArticle A Hybrid Water Distribution Networks Design Optimization Method Based on a Search Space Reduction Approach and a Genetic Algorithm
Water 2017, 9(11), 845; doi:10.3390/w9110845
Received: 30 September 2017 / Revised: 27 October 2017 / Accepted: 29 October 2017 / Published: 2 November 2017
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Abstract
This work presents a new approach to increase the efficiency of the heuristics methods applied to the optimal design of water distribution systems. The approach is based on reducing the search space by bounding the diameters that can be used for every network
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This work presents a new approach to increase the efficiency of the heuristics methods applied to the optimal design of water distribution systems. The approach is based on reducing the search space by bounding the diameters that can be used for every network pipe. To reduce the search space, two opposite extreme flow distribution scenarios are analyzed and velocity restrictions to the pipe flow are then applied. The first scenario produces the most uniform flow distribution in the network. The opposite scenario is represented by the network with the maximum flow accumulation. Both extreme flow distributions are calculated by solving a quadratic programming problem, which is a very robust and efficient procedure. This approach has been coupled to a Genetic Algorithm (GA). The GA has an integer coding scheme and variable number of alleles depending on the number of diameters comprised within the velocity restrictions. The methodology has been applied to several benchmark networks and its performance has been compared to a classic GA formulation with a non-bounded search space. It considerably reduced the search space and provided a much faster and more accurate convergence than the GA formulation. This approach can also be coupled to other metaheuristics. Full article
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Open AccessArticle Research on the Phenomenon of Chinese Residents’ Spiritual Contagion for the Reuse of Recycled Water Based on SC-IAT
Water 2017, 9(11), 846; doi:10.3390/w9110846
Received: 28 September 2017 / Revised: 30 October 2017 / Accepted: 30 October 2017 / Published: 2 November 2017
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Abstract
Recycled water has been widely recognized in the world as an effective approach to relieve the issue of water shortage. Meanwhile, with several decades of development, the insufficiency of technology is no longer the primary factor that restricts the popularization of recycled water.
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Recycled water has been widely recognized in the world as an effective approach to relieve the issue of water shortage. Meanwhile, with several decades of development, the insufficiency of technology is no longer the primary factor that restricts the popularization of recycled water. What makes it difficult to promote the concept of reusing recycled water in China? To solve this issue, a special experiment on the public’s attitude towards the reuse of recycled water was designed based on a Single Category Implicit Association Test (SC-IAT), so as to avoid factors like social preference that can influence the survey results, and to gain the public’s negative implicit attitude towards reusing recycled water reuse, which is close to the public’s real attitude to it. From the perspective of implicit attitude, this research testifies the “spiritual contagion” phenomenon of the public, which refers to refusing recycled water reuse because recycled water is made from sewage treatment. By comparing the implicit attitude to recycled water reuse with the explicit attitude that is acquired from self-reporting questionnaires about reusing recycled water, this research finds that the implicit attitude is more positive than the explicit attitude, which accounts for the phenomenon of “best game no one played” in the promotion of the recycled water reuse, that is, the public though applauding the environment-friendly policy, will not actually use the recycled water. Full article
Open AccessArticle Modeling Regional Soil Water Balance in Farmland of the Middle Reaches of Heihe River Basin
Water 2017, 9(11), 847; doi:10.3390/w9110847
Received: 12 September 2017 / Revised: 28 October 2017 / Accepted: 31 October 2017 / Published: 3 November 2017
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Abstract
Quantifying components of soil water balance in farmland of the middle reaches of Heihe River Basin is essential for efficiently scheduling and allocating limited water resources for irrigation in this arid region. A soil water balance model based on empirical assumptions in the
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Quantifying components of soil water balance in farmland of the middle reaches of Heihe River Basin is essential for efficiently scheduling and allocating limited water resources for irrigation in this arid region. A soil water balance model based on empirical assumptions in the vadose zone of farmland was developed and simulation results were compared/validated with results by the numerical model HYDRUS-1D. Results showed a good coherence between the simulated results of the water balance models and the HYDRUS-1D model in soil water storage, evapotranspiration, deep percolation and groundwater recharge, which indicated that the water balance model was suitable for simulating soil water movement in the study area. Considering the spatial distribution of cropping patterns, groundwater depth and agricultural management, ArcGIS was applied for the pre-/post-processing of the water balance model to quantify the spatial distribution of components of soil water balance in the major cropland in middle reaches of Heihe River Basin. Then, distributions of components of soil water balance in the major cropland under different water-saving irrigation practices during the growing season were predicted and discussed. Simulation results demonstrated that evapotranspiration of the main crops would be more prominently influenced by irrigation quota under deep groundwater depth than that under shallow groundwater depth. Groundwater recharge would increase with the increase of irrigation quota and decrease with the increase of groundwater depth. In general, when groundwater depth reached 3 m, groundwater recharge from root zone was negligible for spring wheat. While when it reached 6 m, groundwater recharge was negligible for maize. Water-saving irrigation practices would help to reduce groundwater recharge with a slight decrease of crop water consumption. Full article
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Open AccessArticle On the Direct Calculation of Snow Water Balances Using Snow Cover Information
Water 2017, 9(11), 848; doi:10.3390/w9110848
Received: 11 April 2017 / Revised: 24 October 2017 / Accepted: 24 October 2017 / Published: 2 November 2017
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Abstract
We present a novel method for the direct determination of the snowmelt coefficient of widely used degree-day models, using only cumulated temperature and precipitation over the days of snow cover. We develop a proof of concept using (1) local measurements of precipitation, temperature
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We present a novel method for the direct determination of the snowmelt coefficient of widely used degree-day models, using only cumulated temperature and precipitation over the days of snow cover. We develop a proof of concept using (1) local measurements of precipitation, temperature and snow water equivalent (SWE) at a set of well-monitored sites in the US, and (2) available time series of snow cover from satellite and gridded daily precipitation and daily average temperature for the study region of South Tyrol, in the Italian Alps. We demonstrate how the method can reproduce the snow water balance to an acceptable extent, critically depending on the accuracy of input precipitation and temperature, highlighting the importance of a reliable representation of weather forcing if the estimate has to be robust and representative. Although not always accurate at a point, our approach yields a SWE reasonably consistent with observations, and snowmelt flows compatible with measured streamflow. At the same time, the model allows an interpretation of discrepancies between observations and simulations to detect inconsistencies between snow cover and weather forcing. This method is in principle applicable for large-scale hydrological assessments thanks to the increasing global coverage of snow cover, precipitation and temperature data. As the only other type of observation available to calibrate models is often streamflow, the direct calibration of the snow component of a model using snow cover and weather forcing reduces the number of model processes and parameters to be calibrated with streamflow, and is expected to increase model robustness. Full article
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Open AccessArticle “In-Process Type” Dynamic Muskingum Model Parameter Estimation Method
Water 2017, 9(11), 849; doi:10.3390/w9110849
Received: 29 August 2017 / Revised: 30 October 2017 / Accepted: 31 October 2017 / Published: 2 November 2017
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Abstract
This paper discusses the Muskingum model as a novel parameter estimation method. Sixty representative floods over the past four decades serve as research objects; a linear Muskingum model and Pigeon-inspired optimization (PIO) algorithm are used to obtain the parameters of each flood. The
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This paper discusses the Muskingum model as a novel parameter estimation method. Sixty representative floods over the past four decades serve as research objects; a linear Muskingum model and Pigeon-inspired optimization (PIO) algorithm are used to obtain the parameters of each flood. The proposed “in-process type” dynamic parameter estimation (IP-DPE) method is used to establish the characteristic attributes set of 50 floods. The characteristic attributes set refers to a set of parameters that could describe the shape, magnitude, and duration of the flood before flood peak; they are the input, whereas parameters K and x of each flood are the output to establish a Neural Network model. Then we input flood characteristic attributes to obtain flood parameters when estimating flood parameters practically. Ten floods were used to test the parameter estimation and flood routing efficacy. The results show that the IP-DPE method can quickly identify parameters and facilitate accurate river flood forecasting. Full article
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Open AccessArticle Statistical and Fractal Approaches on Long Time-Series to Surface-Water/Groundwater Relationship Assessment: A Central Italy Alluvial Plain Case Study
Water 2017, 9(11), 850; doi:10.3390/w9110850
Received: 6 October 2017 / Revised: 25 October 2017 / Accepted: 26 October 2017 / Published: 3 November 2017
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Abstract
In this research, univariate and bivariate statistical methods were applied to rainfall, river and piezometric level datasets belonging to 24-year time series (1986–2009). These methods, which often are used to understand the effects of precipitation on rivers and karstic springs discharge, have been
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In this research, univariate and bivariate statistical methods were applied to rainfall, river and piezometric level datasets belonging to 24-year time series (1986–2009). These methods, which often are used to understand the effects of precipitation on rivers and karstic springs discharge, have been used to assess piezometric level response to rainfall and river level fluctuations in a porous aquifer. A rain gauge, a river level gauge and three wells, located in Central Italy along the lower Pescara River valley in correspondence of its important alluvial aquifer, provided the data. Statistical analysis has been used within a known hydrogeological framework, which has been refined by mean of a photo-interpretation and a GPS survey. Water–groundwater relationships were identified following the autocorrelation and cross-correlation analyses. Spectral analysis and mono-fractal features of time series were assessed to provide information on multi-year variability, data distributions, their fractal dimension and the distribution return time within the historical time series. The statistical–mathematical results were interpreted through fieldwork that identified distinct groundwater flowpaths within the aquifer and enabled the implementation of a conceptual model, improving the knowledge on water resources management tools. Full article
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Open AccessFeature PaperArticle Implementation of DMAs in Intermittent Water Supply Networks Based on Equity Criteria
Water 2017, 9(11), 851; doi:10.3390/w9110851
Received: 26 September 2017 / Revised: 30 October 2017 / Accepted: 31 October 2017 / Published: 3 November 2017
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Abstract
Intermittent supply is a common way of delivering water in many developing countries. Limitations on water and economic resources, in addition to poor management and population growth, limit the possibilities of delivering water 24 h a day. Intermittent water supply networks are usually
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Intermittent supply is a common way of delivering water in many developing countries. Limitations on water and economic resources, in addition to poor management and population growth, limit the possibilities of delivering water 24 h a day. Intermittent water supply networks are usually designed and managed in an empirical manner, or using tools and criteria devised for continuous supply systems, and this approach can produce supply inequity. In this paper, an approach based on the hydraulic capacity concept, which uses soft computing tools of graph theory and cluster analysis, is developed to define sectors, also called district metered areas (DMAs), to produce an equitable water supply. Moreover, this approach helps determine the supply time for each sector, which depends on each sector’s hydraulic characteristics. This process also includes the opinions of water company experts, the individuals who are best acquainted with the intricacies of the network. Full article
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Open AccessArticle Evaluation of Sustainable Use of Water Resources in Beijing Based on Rough Set and Fuzzy Theory
Water 2017, 9(11), 852; doi:10.3390/w9110852
Received: 8 August 2017 / Revised: 15 October 2017 / Accepted: 31 October 2017 / Published: 3 November 2017
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Abstract
Water resources are not only the essence of human life, but also an important prerequisite which ensures the economic and social development of a country or city. Due to chronically global overexploitation, water crises have started to emerge. China, for example, is experiencing
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Water resources are not only the essence of human life, but also an important prerequisite which ensures the economic and social development of a country or city. Due to chronically global overexploitation, water crises have started to emerge. China, for example, is experiencing acute water scarcity. Even its capital, Beijing, faces enormous challenges in the sustainable use of water resources. Combining the compound system of social, economic, and ecological environments with the current situation in Beijing, this study established an evaluation index system. To determine the weight, the rough set theory was adopted in the index layer, fuzzy theory was employed in the rule layer and set pair analysis method, and attribute recognition theory was used as evaluation methods. In order to verify the accuracy of the results, the weights of indices were taken into the evaluation methods mentioned above after being calculated by using the analytic hierarchy process (AHP) and entropy weight method, respectively. The matter-element model was used to evaluate the system and the Spearman correlation coefficient method aimed to compare all the results of the evaluation. The results indicated that water use efficiency and water management have been increasingly improved in Beijing on a yearly basis. Additionally, the results of the Spearman correlation coefficient method showed that the method of weight determination based on rough set and fuzzy theory is feasible in the evaluation of sustainable use of water resources. Full article
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Open AccessArticle Non-Metropolitan Drinking Water Suppliers’ Response to the Diagnostic Tool for Non-Technical Compliance in Limpopo, South Africa
Water 2017, 9(11), 853; doi:10.3390/w9110853
Received: 15 May 2017 / Revised: 8 October 2017 / Accepted: 12 October 2017 / Published: 3 November 2017
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Abstract
Without the planning of non-technical issues, water treatment plants may face challenges in sustaining safe drinking water. Parameters such as the planning of financial resources, human resources, a lack of professional process controllers, poor working conditions, staff shortages and a lack of appropriate
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Without the planning of non-technical issues, water treatment plants may face challenges in sustaining safe drinking water. Parameters such as the planning of financial resources, human resources, a lack of professional process controllers, poor working conditions, staff shortages and a lack of appropriate training of process controllers contribute to the underperformance of drinking water treatment plants. This study aimed at applying the Diagnostic Tool for Non-Technical Compliance to assess the compliance of small drinking water plants with management norms. Six water treatments (Vondo water scheme, Malamulele, Mutshedzi, Mutale regional water treatment plant, Tshedza and Tshedza package plant) were selected from the Vhembe district municipality of the Limpopo province in South Africa. From the abovementioned non-technical parameters, the results showed that during the first assessment period (August 2008 and June 2009) selected water treatment plants scored between 53% and 68% and fell under Class 2, indicating serious challenges requiring attention and improvement. During the second assessment period (November and December 2010), a slight improvement was observed as all plants scored between 72% and 80%, falling under the Class 2 category. Even after corrective actions and remeasurement, none of the plants met the compliance standards, which range from 90% to 100% to obtain the Class 1 compliance standard. The study recommended that tactical and strategic plans that clearly define the operational procedures, process controlling, financial planning, maintenance culture, emergency preparedness and regular monitoring and evaluation should be entrenched for the smooth running of the small water treatment plants. Furthermore, all water services providers and water services authorities should apply the diagnostic tools as developed, which provides guidance on a stepwise procedure on plant operations and management on a daily basis. Full article
(This article belongs to the collection Water Policy Collection)
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Open AccessArticle Removal of Heavy Metals from Urban Stormwater Runoff Using Bioretention Media Mix
Water 2017, 9(11), 854; doi:10.3390/w9110854
Received: 19 September 2017 / Revised: 5 October 2017 / Accepted: 31 October 2017 / Published: 3 November 2017
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Abstract
Heavy metals from urban stormwater runoff are important sources of surface water pollutants. Sand, zeolite, sandy loam, and quartz-sand were separately mixed with lignin to form four bioretention media mixes for experimental study using synthetic stormwater runoff. The average removal efficiencies of four
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Heavy metals from urban stormwater runoff are important sources of surface water pollutants. Sand, zeolite, sandy loam, and quartz-sand were separately mixed with lignin to form four bioretention media mixes for experimental study using synthetic stormwater runoff. The average removal efficiencies of four heavy metals (Cu, Zn, Cd, and Pb) by the four media mixes were all better than 97% at the optimum pH of 6.05 (ranging from 6 to 8) and the seven-day rainfall-event interval. The influence of the influent concentration and the rainfall-event interval on the removal efficiency of heavy metals by the four media mixes was not significant, but the variation of the removal efficiencies at the four-day rainfall-event interval was large. Under acidic conditions, there was a certain heavy metal dissolution in the four reactors, but the effect on the removal efficiency was minor. Heavy metals were present in the media mainly in the form of the residual fraction (>50%). The accumulation of Cu, Zn, and Cd in the surface planting-soil layer (same humus and sandy-loam mixture for all reactors) was significantly larger than the accumulation at deeper depths but not for Pb. Overall, the heavy metal removal efficiencies by the four media mixes were not significantly different, and the choice of the planting-soil layer can become the control factor of heavy metal removal. Full article
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Open AccessArticle Impact of Hybrid Water Supply on the Centralised Water System
Water 2017, 9(11), 855; doi:10.3390/w9110855
Received: 11 September 2017 / Revised: 31 October 2017 / Accepted: 1 November 2017 / Published: 4 November 2017
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Abstract
Traditional (technical) concepts to ensure a reliable water supply, a safe handling of wastewater and flood protection are increasingly criticised as outdated and unsustainable. These so-called centralised urban water systems are further maladapted to upcoming challenges because of their long lifespan in combination
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Traditional (technical) concepts to ensure a reliable water supply, a safe handling of wastewater and flood protection are increasingly criticised as outdated and unsustainable. These so-called centralised urban water systems are further maladapted to upcoming challenges because of their long lifespan in combination with their short-sighted planning and design. A combination of (existing) centralised and decentralised infrastructure is expected to be more reliable and sustainable. However, the impact of increasing implementation of decentralised technologies on the local technical performance in sewer or water supply networks and the interaction with the urban form has rarely been addressed in the literature. In this work, an approach which couples the UrbanBEATS model for the planning of decentralised strategies together with a water supply modelling approach is developed and applied to a demonstration case. With this novel approach, critical but also favourable areas for such implementations can be identified. For example, low density areas, which have high potential for rainwater harvesting, can result in local water quality problems in the supply network when further reducing usually low pipe velocities in these areas. On the contrary, in high demand areas (e.g., high density urban forms) there is less effect of rainwater harvesting due to the limited available space. In these high density areas, water efficiency measures result in the highest savings in water volume, but do not cause significant problems in the technical performance of the potable water supply network. For a more generalised and case-independent conclusion, further analyses are performed for semi-virtual benchmark networks to answer the question of an appropriate representation of the water distribution system in a computational model for such an analysis. Inappropriate hydraulic model assumptions and characteristics were identified for the stated problem, which have more impact on the assessments than the decentralised measures. Full article
(This article belongs to the Special Issue Urban Water Cycle Modelling and Management)
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Open AccessArticle Greedy Algorithms for Sensor Location in Sewer Systems
Water 2017, 9(11), 856; doi:10.3390/w9110856
Received: 4 September 2017 / Revised: 26 October 2017 / Accepted: 31 October 2017 / Published: 4 November 2017
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Abstract
Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors’ location. In this study, a methodology for the optimal
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Wastewater quality monitoring is receiving growing interest with the necessity of developing new strategies for controlling accidental and intentional illicit intrusions. In designing a monitoring network, a crucial aspect is represented by the sensors’ location. In this study, a methodology for the optimal placement of wastewater monitoring sensors in sewer systems is presented. The sensor location is formulated as an optimization problem solved using greedy algorithms (GRs). The Storm Water Management Model (SWMM) was used to perform hydraulic and water-quality simulations. Six different procedures characterized by different fitness functions are presented and compared. The performances of the procedures are tested on a real sewer system, demonstrating the suitability of GRs for the sensor-placement problem. The results show a robustness of the methodology with respect to the detection concentration parameter, and they suggest that procedures with multiple objectives into a single fitness function give better results. A further comparison is performed using previously developed multi-objective procedures with multiple fitness functions solved using a genetic algorithm (GA), indicating better performances of the GR. The existing monitoring network, realized without the application of any sensor design, is always suboptimal. Full article
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Open AccessArticle Analysis of Current and Future SPEI Droughts in the La Plata Basin Based on Results from the Regional Eta Climate Model
Water 2017, 9(11), 857; doi:10.3390/w9110857
Received: 20 July 2017 / Revised: 28 October 2017 / Accepted: 2 November 2017 / Published: 4 November 2017
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Abstract
We identified and analysed droughts in the La Plata Basin (divided into seven sub-basins) for the current period (1961–2005) and estimated their expected evolution under future climate projections for the periods 2011–2040, 2041–2070, and 2071–2099. Future climate projections were analysed from results of
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We identified and analysed droughts in the La Plata Basin (divided into seven sub-basins) for the current period (1961–2005) and estimated their expected evolution under future climate projections for the periods 2011–2040, 2041–2070, and 2071–2099. Future climate projections were analysed from results of the Eta Regional Climate Model (grid resolution of approximately 10 km) forced by the global climate model HadGEM2-ES over the La Plata basin, and considering a RCP4.5 emission scenario. Within each sub-basin, we particularly focused our drought analyses on croplands and grasslands, due to their economic relevance. The three-month Standardized Precipitation Evapotranspiration Index (SPEI3) was used for drought identification and characterization. Droughts were evaluated in terms of time (percentage of time from the total length of each climate scenario), space (percentage of total area), and severity (SPEI3 values) of cells characterized by cropland and grassland for each sub-basin and climate scenario. Drought-severity–area–frequency curves were developed to quantitatively relate the frequency distribution of drought occurrence to drought severity and area. For the period 2011–2040, droughts dominate the northern sub-basins, whereas alternating wet and short dry periods dominate the southern sub-basins. Wet climate spread from south to north within the La Plata Basin as more distant future scenarios were analysed, due to both a greater number of wet periods and fewer droughts. The area of each sub-basin affected by drought in all climate scenarios was highly varied temporally and spatially. The likelihood of the occurrence of droughts differed significantly between the studied cover types in the Lower Paraguay sub-basin, being higher for cropland than for grassland. Mainly in the Upper Paraguay and in the Upper Paraná basins the climate projections for all scenarios showed an increase of moderate and severe droughts over large regions dedicated to crops and grasses. On the other hand, for the near future, the Lower Uruguay and the River Plata basins showed a decrease of drought severity compared to the current period. Projections suggest an increase in competition among uses in these regions and the need for a potential relocation of certain crops from the northern regions towards cooler regions located in the centre and south. Further research should consider other climate projections and perform high spatial resolution studies in localized areas. Full article
(This article belongs to the Special Issue Drought Monitoring, Forecasting, and Risk Assessment)
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Open AccessArticle Simulation of Infrastructure Options for Urban Water Management in Two Urban Catchments in Bogotá, Colombia
Water 2017, 9(11), 858; doi:10.3390/w9110858
Received: 27 August 2017 / Revised: 30 October 2017 / Accepted: 1 November 2017 / Published: 5 November 2017
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Abstract
Urban areas are currently experiencing rapid growth, which brings with it increases in the population, the expansion of impervious surfaces, and an overall jump in the environmental and hydrological impact. To mitigate such an impact, different strategies proposed to tackle this problem often
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Urban areas are currently experiencing rapid growth, which brings with it increases in the population, the expansion of impervious surfaces, and an overall jump in the environmental and hydrological impact. To mitigate such an impact, different strategies proposed to tackle this problem often vary; for example, stormwater tanks, the reuse of wastewater and grey water, the installation of equipment to reduce water consumption, and education-based approaches. Consequently, this article presents the simulation and evaluation of implementing infrastructure options (stormwater harvesting, reuse of industrial waters, water-saving technology in residential sectors, and reuse of water from washing machines) for managing urban water in two urban catchments (Fucha and Tunjuelo) in Bogotá, Colombia, over three periods: baseline, 10 years, and 20 years. The simulation was performed using the software Urban Volume Quality (UVQ) and revealed a possible reduction in drinking water consumption of up to 47% for the Fucha Catchment and 40% for the Tunjuelo Catchment; with respect to wastewater, the reduction was up to 20% for the Fucha Catchment and 25% for the Tunjuelo Catchment. Lastly, two scenarios were evaluated in terms of potential savings related to water supply and sewage fees. The implementation of strategies 3 and 6 insofar as these two strategies impacted the hydric resources. Therefore, there would be a significant reduction in contaminant loads and notable economic benefits attributable to implementing these strategies. Full article
(This article belongs to the Special Issue Urban Water Cycle Modelling and Management)
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Open AccessArticle Effects of Climate Change on 2-Methylisoborneol Production in Two Cyanobacterial Species
Water 2017, 9(11), 859; doi:10.3390/w9110859 (registering DOI)
Received: 24 September 2017 / Revised: 30 October 2017 / Accepted: 2 November 2017 / Published: 22 November 2017
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Abstract
2-Methylisoborneol (2-MIB) is a common off-flavor metabolite, and it has a very low odor threshold value. 2-MIB is produced by a variety of cyanobacteria and heterotrophic bacteria. In this study, Dolichospermum spiroides (Anabaena spiroides, FACHB 498) and Planktothrix sp. (FACHB 1371)
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2-Methylisoborneol (2-MIB) is a common off-flavor metabolite, and it has a very low odor threshold value. 2-MIB is produced by a variety of cyanobacteria and heterotrophic bacteria. In this study, Dolichospermum spiroides (Anabaena spiroides, FACHB 498) and Planktothrix sp. (FACHB 1371) were investigated. The influence of high temperature (27, 35, and 40 °C) and dissolved inorganic carbon (DIC, 18.4, 27.5, and 36.7 mg/L) on the two 2-MIB-producing cyanobacteria were simulated to study the effect of climate change on 2-MIB production. DIC had an effect on 2-MIB production by Planktothrix sp. The results showed that the highest DIC concentration (36.7 mg/L) led to the fastest algal growth, which increased 2-MIB production by Planktothrix sp. However, 40 °C killed all the cyanobacteria. The higher temperature (35 °C) shortened the lifecycle of the two cyanobacteria because it moved forward their logarithmic phase compared to 27 °C. The 2-MIB-producing potential of Dolichospermum spiroides may increase at 35 °C. The Dolichospermum spiroides results showed that the fluorescence intensity and the concentration of extracellular 2-MIB were highly correlated (r2 ≥ 0.90). At 35 °C, there was a stronger correlation between extracellular dissolved organic matters’ (DOMs, fulvic acid (P3 (r2 = 0.90)), humic acid (P4 (r2 = 0.92)) and the soluble microbial metabolites’ (P5 (r2 = 0.71)) fluorescence peak intensities and 2-MIB concentration. The Dolichospermum sproides 2-MIB-producing potential was affected by extracellular humus. The Planktothrix sp. 2-MIB-producing potential declined in general over the growth period. In addition, temperature had no significant effect on the Planktothrix sp. 2-MIB-producing potential and the extracellular 2-MIB component. Full article
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Open AccessArticle Decomposition Analysis of Water Treatment Technology Patents
Water 2017, 9(11), 860; doi:10.3390/w9110860
Received: 25 August 2017 / Revised: 1 November 2017 / Accepted: 3 November 2017 / Published: 6 November 2017
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Abstract
Water treatment technology development supports a steady, safe water supply. This study examines trends in water treatment technology innovations, using 227,365 patent granted data published from 1993 to 2016 as an indicator of changing research and development (R&D) priorities. To clarify changes in
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Water treatment technology development supports a steady, safe water supply. This study examines trends in water treatment technology innovations, using 227,365 patent granted data published from 1993 to 2016 as an indicator of changing research and development (R&D) priorities. To clarify changes in R&D priorities, we used a decomposition analysis framework that classified water treatment technologies into five types: conventional treatment (117,974 patents, 51.9%), biological treatment (40,300 patents, 17.7%), multistage treatment (45,732 patents, 20.1%), sludge treatment (15,237 patents, 6.7%), and other treatments (8122 patents, 3.6%). The results showed that the number of water treatment technology patents granted increased more than 700% from 1993 to 2016; in particular, the number of multistage water treatment patents granted rapidly grew. The main driver of this growth was expansion in the R&D activity scale and an increase in the priority of multistage water treatment technology in China. Additionally, the trends and priority changes in water treatment technology inventions varied by country and technology groups, which implied that an international policy framework for water treatment technology development should recognize that R&D priorities need to reflect the diverse characteristics of countries and technologies. Full article
(This article belongs to the Special Issue Recent Advances in Water Management: Saving, Treatment and Reuse)
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Open AccessArticle Building a High-Precision 2D Hydrodynamic Flood Model Using UAV Photogrammetry and Sensor Network Monitoring
Water 2017, 9(11), 861; doi:10.3390/w9110861
Received: 14 September 2017 / Revised: 23 October 2017 / Accepted: 4 November 2017 / Published: 6 November 2017
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Abstract
This paper explores the potential of the joint application of unmanned aerial vehicle (UAV)-based photogrammetry and an automated sensor network for building a hydrodynamic flood model of a montane stream. UAV-based imagery was used for three-dimensional (3D) photogrammetric reconstruction of the stream channel,
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This paper explores the potential of the joint application of unmanned aerial vehicle (UAV)-based photogrammetry and an automated sensor network for building a hydrodynamic flood model of a montane stream. UAV-based imagery was used for three-dimensional (3D) photogrammetric reconstruction of the stream channel, achieving a resolution of 1.5 cm/pixel. Automated ultrasonic water level gauges, operating with a 10 min interval, were used as a source of hydrological data for the model calibration, and the MIKE 21 hydrodynamic model was used for building the flood model. Three different horizontal schematizations of the channel—an orthogonal grid, curvilinear grid, and flexible mesh—were used to evaluate the effect of spatial discretization on the results. The research was performed on Javori Brook, a montane stream in the Sumava (Bohemian Forest) Mountains, Czech Republic, Central Europe, featuring a fast runoff response to precipitation events and that is located in a core zone of frequent flooding. The studied catchments have been, since 2007, equipped with automated water level gauges and, since 2013, under repeated UAV monitoring. The study revealed the high potential of these data sources for applications in hydrodynamic modeling. In addition to the ultra-high levels of spatial and temporal resolution, the major contribution is in the method’s high operability, enabling the building of highly detailed flood models even in remote areas lacking conventional monitoring. The testing of the data sources and model setup indicated the limitations of the UAV reconstruction of the stream bathymetry, which was completed by the geodetic-grade global navigation satellite system (GNSS) measurements. The testing of the different model domain schematizations did not indicate the substantial differences that are typical for conventional low-resolution data, proving the high reliability of the tested modeling workflow. Full article
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Open AccessFeature PaperArticle Lateral Saturated Hydraulic Conductivity of Soil Horizons Evaluated in Large-Volume Soil Monoliths
Water 2017, 9(11), 862; doi:10.3390/w9110862
Received: 26 September 2017 / Revised: 21 October 2017 / Accepted: 2 November 2017 / Published: 6 November 2017
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Abstract
Evaluating the lateral saturated hydraulic conductivity, Ks,l, of soil horizons is crucial for understanding and modelling the subsurface flow dynamics in many shallow hill soils. A Ks,l measurement method should be able to catch the effects of soil heterogeneities governing
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Evaluating the lateral saturated hydraulic conductivity, Ks,l, of soil horizons is crucial for understanding and modelling the subsurface flow dynamics in many shallow hill soils. A Ks,l measurement method should be able to catch the effects of soil heterogeneities governing hydrological processes at the scale of interest, in order to yield Ks,l representative values over large spatial scales. This study aims to develop a field technique to determine spatially representative Ks,l values of soil horizons of an experimental hillslope. Drainage experiments were performed on soil monoliths of about 0.12 m3 volume, encased in situ with polyurethane foam. Median Ks,l of 2450 mm·h−1 and 552 mm·h−1 were estimated in the A and B horizon, respectively. In the upper part of the B horizon, the median Ks,l was 490 mm·h−1, whereas it mostly halved near the underlying restricting layer. The decline of Ks,l values with depth was consistent with the water-table dynamics observed at the same site in previous studies. Moreover, the Ks,l from the monoliths were in line with large spatial-scale Ks,l values reported from the hillslope in a prior investigation based on drain data analysis. This indicated that the large-scale hydrological effects of the macropore network were well represented in the investigated soil blocks. Our findings suggest that performing drainage experiments on large-volume monoliths is a promising method for characterizing lateral conductivities over large spatial scales. This information could improve our understanding of hydrological processes and can be used to parameterize runoff-generation models at hillslope and catchment scale. Full article
(This article belongs to the Special Issue Soil Water Conservation: Dynamics and Impact)
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Open AccessArticle The Biomass and Physiological Responses of Vallisneria natans (Lour.) Hara to Epiphytic Algae and Different Nitrate-N Concentrations in the Water Column
Water 2017, 9(11), 863; doi:10.3390/w9110863 (registering DOI)
Received: 4 September 2017 / Revised: 31 October 2017 / Accepted: 2 November 2017 / Published: 22 November 2017
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Abstract
Increasing N concentration and the high density of epiphytic algae are both key factors leading to the decline of submerged macrophytes in many eutrophic lakes. In order to investigate the impacts of increased nitrate-N concentration and the growth of epiphytic algae on the
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Increasing N concentration and the high density of epiphytic algae are both key factors leading to the decline of submerged macrophytes in many eutrophic lakes. In order to investigate the impacts of increased nitrate-N concentration and the growth of epiphytic algae on the decline of submerged vegetation, we conducted a 2 × 4 factorial experiment with the submerged macrophyte Vallisneria natans (Lour.) Hara by measuring the biomass of plants and some physiological indexes in leaves of V. natans under four nitrate-N concentrations in the water column (0.5, 2.5, 5, and 10 mg/L) and two epiphytic groups (epiphytic algae group and no epiphytic algae group). The results suggested that epiphytic algae could impose adverse effects on the biomass accumulation of V. natans, while the increasing nitrate-N concentration (0.5–10 mg/L) could oppositely promote this process and counteract the adverse effect of epiphytic algae. When nitrate-N concentration was 5 mg/L, the total chlorophyll content in leaves of V. natans in the epiphytic algae group was prominently lower compared with the no epiphytic algae group, while MDA, free proline, and anti-oxidant enzyme (SOD, POD, CAT) activities were significantly higher. Overhigh nitrate-N concentration in the water column also directly imposed adverse effects on the physiology of V. natans. When nitrate-N concentration was over 5 mg/L, the total chlorophyll content and free proline decreased in the no epiphytic algae group, while soluble carbohydrates and soluble proteins decreased when nitrate-N was over 2.5 mg/L. Meanwhile, epiphytic algae and nitrate-N content imposed a synergetic effect on the anti-oxidant enzyme activities of V. natans. When nitrate-N concentration was over 5 mg/L, SOD, POD, and CAT activities kept constant or decreased, which indicated that the oxidation resistance of V. natans was inhibited by stress. Our results indicate that epiphytic algae and increasing nitrate-N concentration in the water column could severally or synergistically impose adverse effects on the physiology of submerged macrophytes and are both key factors leading to the decline of submerged macrophytes. Full article
(This article belongs to the Special Issue Eutrophication of Waterways: An Old Problem with Modern Consequences)
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Open AccessArticle Incorporating Temporal and Spatial Variations of Groundwater into the Construction of a Water-Based Ecological Network: A Case Study in Denko County
Water 2017, 9(11), 864; doi:10.3390/w9110864
Received: 29 June 2017 / Revised: 27 September 2017 / Accepted: 1 November 2017 / Published: 6 November 2017
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Abstract
It is of great practical significance to construct a water-based ecological network in arid and semi-arid areas. The spatial distribution of water resources is one of the most important factors in determining the ecological stability of such areas. In this study, groundwater level
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It is of great practical significance to construct a water-based ecological network in arid and semi-arid areas. The spatial distribution of water resources is one of the most important factors in determining the ecological stability of such areas. In this study, groundwater level trends were analyzed with a model called Empirical Mode Decomposition (EMD). The temporal and spatial evolution of groundwater depth data from 1990 to 2016 were analyzed. The surface water bodies were analyzed using a point pattern analysis method. Based on this, a water-based ecological network was constructed with a minimum cumulative resistance surface model. The study indicated that the trend lines for the groundwater tables of 17 wells could be divided into five types in Denko County. The landscape types that changed from a desert landscape to an oasis landscape had a positive impact on groundwater. Precipitation trend was related to the spatial distribution of the groundwater depth, and the spatial pattern of the water nodes was characterized by a small-scale highly aggregated distribution and a large-scale uniform distribution in Denko County. These results suggest that for the stability of arid and semi-arid ecological environments, the appropriate human intervention (such as construction of an artificial oasis) is of great significance. Based on the analysis of groundwater and surface water bodies, a water-based ecological network in Denko County, which consisted of 391 ecological sources and 7360 ecological corridors, was constructed in 2016. The water-based ecological network constructed in this study was more sustainable and stable, and also suitable for arid and semi-arid areas, which is of great practical significance and application value. Full article
(This article belongs to the Special Issue Sustainable Water Management within Inland River Watershed)
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Open AccessArticle Cyanobacterial Nitrogen Fixation Influences the Nitrogen Removal Efficiency in a Constructed Wetland
Water 2017, 9(11), 865; doi:10.3390/w9110865
Received: 18 September 2017 / Revised: 1 November 2017 / Accepted: 3 November 2017 / Published: 7 November 2017
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Abstract
Nitrogen removal efficiency in constructed wetlands (CW) is influenced by multiple environmental factors. However, little is known about the role of cyanobacterial nitrogen fixation in affecting nitrogen removal efficiency. This study investigated how cyanobacterial nitrogen fixation affects the efficiency, at which a CW
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Nitrogen removal efficiency in constructed wetlands (CW) is influenced by multiple environmental factors. However, little is known about the role of cyanobacterial nitrogen fixation in affecting nitrogen removal efficiency. This study investigated how cyanobacterial nitrogen fixation affects the efficiency, at which a CW removes nitrogen from an associated artificial lake (AL) in Beijing. For this purpose, we measured cell densities of N-fixing and non-N-fixing cyanobacteria, the aquatic nitrogen fixation rate (RNfix), and the concentration of various nitrogen fractions over the growing season (April–November) of 2014 in both AL and CW. We found that the removal of particulate organic nitrogen (PON) contributed to >90% of the total nitrogen removal in the CW. The removal efficiency of PON was lower during August–October (55.45 ± 27.49%) than during April–July (68.86 ± 8.83%). Phytoplankton proliferation in summer, as one of the main sources of PON, may have exceeded the capacity of the CW and led to declines in PON removal efficiency. RNfix peaked in July–October (3–169 ng N·L−1·h−1) and was positively correlated with both PON concentration and the cell density of N-fixing Anabaena sp. over the growing season, suggesting that aquatic nitrogen fixation (primarily in the AL) may increase PON and thereby reduce the its removal efficiency in the CW. Full article
(This article belongs to the Special Issue Biological Treatment of Wastewater)
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Open AccessArticle Runoff Simulation by SWAT Model Using High-Resolution Gridded Precipitation in the Upper Heihe River Basin, Northeastern Tibetan Plateau
Water 2017, 9(11), 866; doi:10.3390/w9110866
Received: 25 September 2017 / Revised: 29 October 2017 / Accepted: 2 November 2017 / Published: 7 November 2017
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Abstract
The scarcity and uneven distribution of precipitation stations in the inland river basins of the Northeastern Tibetan Plateau restrict the application of the distributed hydrological model and spatial analysis of water balance component characteristics. This study used the upper Heihe River Basin as
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The scarcity and uneven distribution of precipitation stations in the inland river basins of the Northeastern Tibetan Plateau restrict the application of the distributed hydrological model and spatial analysis of water balance component characteristics. This study used the upper Heihe River Basin as a case study, and daily gridded precipitation data with 3 km resolution based on the spatial interpolation of gauged stations and a regional climate model were used to construct a soil and water assessment tool (SWAT) model. The aim was to validate the precision of high-resolution gridded precipitation for hydrological simulation in data-scarce regions; a scale transformation method was proposed by building virtual stations and calculating the lapse rate to overcome the defects of the SWAT model using traditional precipitation station data. The gridded precipitation was upscaled from the grid to the sub-basin scale to accurately represent sub-basin precipitation input data. A satisfactory runoff simulation was achieved, and the spatial variability of water balance components was analysed. Results show that the precipitation lapse rate ranges from 40 mm/km to 235 mm/km and decreases from the southeastern to the northwestern areas. The SWAT model achieves monthly runoff simulation compared with gauged runoff from 2000 to 2014; the determination coefficients are higher than 0.71, the Nash–Sutcliffe efficiencies are higher than 0.76, and the percentage bias is controlled within ±15%. Meadow and sparse vegetation are the major water yield landscapes, and the elevation band from 3500 m to 4500 m is the major water yield area. Precipitation and evapotranspiration present a slightly increasing trend, whereas water yield and soil water content present a slightly decreasing trend. This finding indicates that the high-resolution gridded precipitation data fully depict its spatial heterogeneity, and scale transformation significantly promotes the application of the distributed hydrological model in inland river basins. The spatial variability of water balance components can be quantified to provide references for the integrated assessment and management of basin water resources in data-scarce regions. Full article
(This article belongs to the Special Issue Sustainable Water Management within Inland River Watershed)
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Open AccessCommunication An Environmentally Benign Approach for As (V) Absorption from Wastewater Using Untreated Coffee Grounds—Preliminary Results
Water 2017, 9(11), 867; doi:10.3390/w9110867
Received: 13 September 2017 / Revised: 16 October 2017 / Accepted: 5 November 2017 / Published: 7 November 2017
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Abstract
Arsenic contamination of water is a worldwide issue due to its severe effects on the human body. Coffee grounds are a porous material with network structures, making it absorb other substances such as some gases or elements. In this research, renewable coffee wastes
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Arsenic contamination of water is a worldwide issue due to its severe effects on the human body. Coffee grounds are a porous material with network structures, making it absorb other substances such as some gases or elements. In this research, renewable coffee wastes were used as an adsorbent to extract arsenic (As) from wastewater. In order to evaluate the usefulness of untreated coffee grounds, a series of preliminary tests for attachment of arsenic to coffee grounds were provided. The Brunauer–Emmett–Teller (BET) surface area and adsorption–desorption isotherms of an untreated coffee ground obtained from N2 gas adsorption were provided, and pore sizes was obtained using Barrett–Joyner–Halenda (BJH) method. The adsorption capacities of the coffee waste were verified through a series of experimental processes changing the conditions such as concentration of arsenic, initial amount of coffee grounds, and pH. The maximum absorption concentration of 6.44 mg/L on 1 g of coffee grounds at 1.00 mM of arsenic solution was observed. It was demonstrated that the modification by the cation species or pretreatment processes, such as calcination, will be necessary to enhance the absorption capacity for the extraction of arsenic. Full article
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Open AccessFeature PaperArticle Sustainable Water Management in the Tourism Economy: Linking the Mediterranean’s Traditional Rainwater Cisterns to Modern Needs
Water 2017, 9(11), 868; doi:10.3390/w9110868
Received: 10 August 2017 / Revised: 3 November 2017 / Accepted: 4 November 2017 / Published: 8 November 2017
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Abstract
Communities on islands with mass-tourism, like Santorini, rely on vast quantities of water to develop the local economy. Today’s inhabitants of Santorini have largely abandoned the traditional cisterns that were used to sustain the island’s pre-modern civilizations in favor of water obtained from
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Communities on islands with mass-tourism, like Santorini, rely on vast quantities of water to develop the local economy. Today’s inhabitants of Santorini have largely abandoned the traditional cisterns that were used to sustain the island’s pre-modern civilizations in favor of water obtained from desalinization, ship deliveries, and well withdrawals. In June 2016, Cornell University researchers worked with the Water and Sewage Authority of Thera (DEYATH) to assess the viability of improving sustainability and water efficiency by restoring traditional rainwater harvesting and storage cisterns. The team surveyed five cisterns, held meetings with water authority staff and mayoral leadership, conducted interviews with local tourism stakeholders, and coordinated with Global Water Partnership-Mediterranean. One conclusion was that cisterns could be rehabilitated as decentralized storage reservoirs and integrated into the island’s centralized water systems, or alternatively, serve as educational and cultural spaces used to communicate the importance of water to residents and tourists. The research findings highlight how multi-stakeholder partnerships could assist local authorities with developing new water management initiatives to foster more sustainable models of tourism development. Full article
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Open AccessArticle Simulating the Effects of Agricultural Management on Water Quality Dynamics in Rice Paddies for Sustainable Rice Production—Model Development and Validation
Water 2017, 9(11), 869; doi:10.3390/w9110869
Received: 12 October 2017 / Revised: 27 October 2017 / Accepted: 30 October 2017 / Published: 8 November 2017
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Abstract
The Agricultural Policy/Environmental eXtender (APEX) model is widely used for evaluating agricultural conservation efforts and their effects on soil and water. A key component of APEX application in Korea is simulating the water quality impacts of rice paddies because rice agriculture claims the
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The Agricultural Policy/Environmental eXtender (APEX) model is widely used for evaluating agricultural conservation efforts and their effects on soil and water. A key component of APEX application in Korea is simulating the water quality impacts of rice paddies because rice agriculture claims the largest cropland area in the country. In this study, a computational module called APEX-Paddy (National Academy of Agricultural Sciences, Wanju, Korea) is developed to simulate water quality with considering pertinent paddy management practices, such as puddling and flood irrigation management. Data collected at two experimental paddy sites in Korea were used to calibrate and validate the model. Results indicate that APEX-Paddy performs well in predicting runoff discharge rate and nitrogen yield while the original APEX highly overestimates runoff rates and nitrogen yields on large storm events. With APEX-Paddy, simulated and observed flow and mineral nitrogen yield (QN) are found to be highly correlated after calibration (Nash & Sutcliffe Efficiency (NSE) = 0.87 and Percent Bias (PBIAS) = −14.6% for flow; NSE = 0.68 and PBIAS = 2.1% for QN). Consequently, the APEX-Paddy showed a greater accuracy in flow and QN prediction than the original APEX modeling practice using the SCS-CN (Soil Conservation Service-Curve Number) method. Full article
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Open AccessArticle An Investigation into Sub-Basin Rainfall Losses in Different Underlying Surface Conditions Using HEC-HMS: A Case Study of a Loess Hilly Region in Gedong Basin in the Western Shanxi Province of China
Water 2017, 9(11), 870; doi:10.3390/w9110870
Received: 25 September 2017 / Revised: 31 October 2017 / Accepted: 4 November 2017 / Published: 8 November 2017
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Abstract
Basins located in loess hilly–gully regions often suffer flood disasters during the flood season. Meanwhile, the underlying surface of the region can increase the rainfall losses, thereby reducing the flood volume. Therefore, the prediction of rainfall losses on the underlying surface is necessary
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Basins located in loess hilly–gully regions often suffer flood disasters during the flood season. Meanwhile, the underlying surface of the region can increase the rainfall losses, thereby reducing the flood volume. Therefore, the prediction of rainfall losses on the underlying surface is necessary for scientifically and reasonably forecasting the flood volume. The relationship between the rainfall losses and underlying characteristics was investigated and a method for predicting the rainfall losses using HEC-HMS was presented in this paper with a case study in the Gedong basin, a typical loess hilly region of western Shanxi Province in northern China. Results showed that HEC-HMS could be applied to loess hilly–gully regions. The loss computation results suggested that the losses of sub-basins varied with the density of rainfall. The analysis of influences of rainfall losses, including forestland percentage and slope, indicated that the former had a positive impact, while the latter had a negative influence. The impact of forestland percentage is larger than that of slope. Furthermore, with the increase of forestland percentage, its correlation with rainfall losses was enhanced, and the correlation coefficient ranged between 0.64 and 0.84 from the 1970s to the 2010s. Full article
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Open AccessFeature PaperArticle Unravelling the Relative Contribution of Dissolved Carbon by the Red River to the Atchafalaya River
Water 2017, 9(11), 871; doi:10.3390/w9110871
Received: 15 August 2017 / Revised: 27 October 2017 / Accepted: 4 November 2017 / Published: 8 November 2017
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Abstract
The Atchafalaya River (AR), North America’s largest swamp river, annually discharges a large volume of freshwater (nearly 200 km3), delivering ~25% of the Mississippi River’s (MR) flow and the entire Red River’s (RR) flow into the Gulf of Mexico. Studies have reported higher
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The Atchafalaya River (AR), North America’s largest swamp river, annually discharges a large volume of freshwater (nearly 200 km3), delivering ~25% of the Mississippi River’s (MR) flow and the entire Red River’s (RR) flow into the Gulf of Mexico. Studies have reported higher levels of organic carbon in the AR’s outlets compared to the MR’s outlet, raising questions about local carbon sources. In this study, we investigated dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) inputs into the AR from the RR and MR using DOC and DIC concentrations, mass loading, and isotopic signature (δ13C) analyses. Monthly river water sampling was conducted in the MR and RR near their confluence where the AR is formed from May 2015–May 2016. DIC concentrations in the RR were found to be only half of those found in the MR, while the RR’s DOC concentrations were on average 1.8 times higher than those found in the MR. Based on the models developed for this study period, the RR’s contribution to DIC mass loading in the AR represented 1.41 teragrams (Tg) (or, 29.7%) of the total 4.76 Tg DIC transported by both tributaries, while its contribution to DOC mass loading was disproportionately high, accounting for 1.74 Tg of the 2.75 Tg DOC (or, 63.2% of total DOC) entering the AR. Both δ13CDIC and δ13CDOC showed significantly more negative values in the RR than those found in the MR. Significant correlation between δ13CDIC and δ13CDOC isotope values in the RR indicated interrelation of dissolved carbon processing, which was not observable in the MR. These results strongly suggest that the RR is an extremely significant source of DOC to the AR, and thus the Gulf of Mexico, and additionally plays an important role in diluting the anthropogenically enhanced DIC fluxes of the MR. Full article
(This article belongs to the Special Issue Recent Progress in River Biogeochemistry Research)
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Open AccessFeature PaperArticle Compound-Specific Isotope Analysis (CSIA) Application for Source Apportionment and Natural Attenuation Assessment of Chlorinated Benzenes
Water 2017, 9(11), 872; doi:10.3390/w9110872
Received: 22 September 2017 / Revised: 25 October 2017 / Accepted: 1 November 2017 / Published: 9 November 2017
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Abstract
In light of the complex management of chlorobenzene (CB) contaminated sites, at which a hydraulic barrier (HB) for plumes containment is emplaced, compound-specific stable isotope analysis (CSIA) has been applied for source apportionment, for investigating the relation between the upgradient and downgradient of
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In light of the complex management of chlorobenzene (CB) contaminated sites, at which a hydraulic barrier (HB) for plumes containment is emplaced, compound-specific stable isotope analysis (CSIA) has been applied for source apportionment, for investigating the relation between the upgradient and downgradient of the HB, and to target potential CB biodegradation processes. The isotope signature of all the components potentially involved in the degradation processes has been expressed using the concentration-weighted average δ13C of CBs + benzene (δ13Csum). Upgradient of the HB, the average δ13Csum of −25.6‰ and −29.4‰ were measured for plumes within the eastern and western sectors, respectively. Similar values were observed for the potential sources, with δ13Csum values of −26.5‰ for contaminated soils and −29.8‰ for the processing water pipeline in the eastern and western sectors, respectively, allowing for apportioning of these potential sources to the respective contaminant plumes. For the downgradient of the HB, similar CB concentrations but enriched δ13Csum values between −24.5‰ and −25.9‰ were measured. Moreover, contaminated soils showed a similar δ13Csum signature of −24.5‰, thus suggesting that the plumes likely originate from past activities located in the downgradient of the HB. Within the industrial property, significant δ13C enrichments were measured for 1,2,4-trichlorobenzene (TCB), 1,2-dichlorobenzene (DCB), 1,3-DCB, and 1,4-DCBs, thus suggesting an important role for anaerobic biodegradation. Further degradation of monochlorobenzene (MCB) and benzene was also demonstrated. CSIA was confirmed to be an effective approach for site characterization, revealing the proper functioning of the HB and demonstrating the important role of natural attenuation processes in reducing the contamination upgradient of the HB. Full article
(This article belongs to the Special Issue Isotopes in Hydrology and Hydrogeology)
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Open AccessArticle Spatiotemporal Variability of Extreme Summer Precipitation over the Yangtze River Basin and the Associations with Climate Patterns
Water 2017, 9(11), 873; doi:10.3390/w9110873
Received: 28 August 2017 / Revised: 6 November 2017 / Accepted: 7 November 2017 / Published: 9 November 2017
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Abstract
Understanding the spatiotemporal variability of seasonal extreme precipitation and its linkage with climate patterns is of great importance for water resource management over the Yangtze River Basin. Hence, this study examined the spatiotemporal variability of seasonal extreme precipitation through the archetypal analysis (AA),
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Understanding the spatiotemporal variability of seasonal extreme precipitation and its linkage with climate patterns is of great importance for water resource management over the Yangtze River Basin. Hence, this study examined the spatiotemporal variability of seasonal extreme precipitation through the archetypal analysis (AA), by which observations were decomposed and characterized as several extreme modes. Six archetypes were identified and can obviously exhibit the features of events with above average or below average precipitation. Summer precipitation is the most variable compared to the winter, spring, and autumn precipitation through the trend analysis. It ranged from extremely dry (A6) to normal (A1 and A2) to extremely wet (A4). Climate teleconnections to the four archetypes for summer precipitation and relative importance of climate patterns were thus investigated. Results show that El Niño Southern Oscillation index is the strongest determinant of the ensuing archetypes representing the events with above average precipitation, while the Atlantic Multi-decadal Oscillation (AMO) contributes most to the events with below-average precipitation. A warm phase of the Pacific Decadal Oscillation (PDO) is significantly correlated with the above-average precipitation. Full article
(This article belongs to the Special Issue Impact of Climate on Hydrological Extremes)
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Open AccessArticle Efficient Use of Water Resources in the Steel Industry
Water 2017, 9(11), 874; doi:10.3390/w9110874
Received: 29 September 2017 / Revised: 3 November 2017 / Accepted: 8 November 2017 / Published: 10 November 2017
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Abstract
In the steel sector water management aims at improving the sustainability of the production cycle, resulting in resource efficiency benefits and in reduced water demand and costs. To be reused, water needs to be cooled and desalinized to avoid salt concentration in water
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In the steel sector water management aims at improving the sustainability of the production cycle, resulting in resource efficiency benefits and in reduced water demand and costs. To be reused, water needs to be cooled and desalinized to avoid salt concentration in water circulation systems. The presented work includes two case studies carried out in an integrated steelmaking plant, respectively, to evaluate the possible implementation of ultrafiltration and reverse osmosis to reduce salt concentration in water streams and to investigate, through modelling and simulation, a process integration solution to improve water efficiency. Results showed that most salts are removed by reverse osmosis and that its coupling with ultrafiltration allows obtaining very high quality water; reuse of desalinated wastewater resulted in being more suitable and economically viable than its discharge. Moreover, modelling and simulation showed that the considered blowdown could be reused without significant changes in the receiving water network area. The industrial implementation of water recovery solutions can lead to a decrease of fresh water consumption, effluent discharge, and to improvement of product quality and equipment service life. The considered desalination technologies are transferable and easily implementable, and modelling and simulation are very useful in order to evaluate process modifications before real implementation. Full article
(This article belongs to the Special Issue Sustainable Water Supply through Desalination and Wastewater Reuse)
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Open AccessArticle An Integrated Approach Based on Numerical Modelling and Geophysical Survey to Map Groundwater Salinity in Fractured Coastal Aquifers
Water 2017, 9(11), 875; doi:10.3390/w9110875
Received: 27 July 2017 / Revised: 7 November 2017 / Accepted: 7 November 2017 / Published: 10 November 2017
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Abstract
Aquifer over-exploitation may increase coastal seawater intrusion by reducing freshwater availability. Fractured subsurface formations commonly host important freshwater reservoirs along sea coasts. These water resources are particularly vulnerable to the contamination due to seawater infiltration occurring through rapid pathways via fractures. Modeling of
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Aquifer over-exploitation may increase coastal seawater intrusion by reducing freshwater availability. Fractured subsurface formations commonly host important freshwater reservoirs along sea coasts. These water resources are particularly vulnerable to the contamination due to seawater infiltration occurring through rapid pathways via fractures. Modeling of density driven fluid flow in fractured aquifers is complex, as their hydrodynamics are controlled by interactions between preferential flow pathways, 3D interconnected fractures and rock-matrix porosity distribution. Moreover, physical heterogeneities produce highly localized water infiltrations that make the modeling of saltwater transport in such aquifers very challenging. The new approach described in this work provides a reliable hydrogeological model suitable to reproduce local advancements of the freshwater/saltwater wedge in coastal aquifers. The proposed model use flow simulation results to estimate water salinities in groundwater at a specific depth (1 m) below water table by means of positions of the Ghyben-Herzberg saltwater/freshwater sharp interface along the coast. Measurements of salinity in 25 boreholes (i.e., salinity profiles) have been used for the model calibration. The results provide the groundwater salinity map in freshwater/saltwater transition coastal zones of the Bari (Southern Italy) fractured aquifer. Non-invasive geophysical measurements in groundwater, particularly into vertical 2D vertical cross-sections, were carried out by using the electrical resistivity tomography (ERT) in order to validate the model results. The presented integrated approach is very easy to apply and gives very realistic salinity maps in heterogeneous aquifers, without simulating density driven water flow in fractures. Full article
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Open AccessArticle Drought Characteristics over the Western Cape Province, South Africa
Water 2017, 9(11), 876; doi:10.3390/w9110876
Received: 24 August 2017 / Revised: 3 November 2017 / Accepted: 7 November 2017 / Published: 10 November 2017
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Abstract
Drought is a creeping phenomenon whose effects evolve with time, yet the start and end is often only clear in the hindsight. The present study assessed drought conditions using two categories of drought indicators computed from precipitation data sets measured by weather stations
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Drought is a creeping phenomenon whose effects evolve with time, yet the start and end is often only clear in the hindsight. The present study assessed drought conditions using two categories of drought indicators computed from precipitation data sets measured by weather stations across the Western Cape Province, South Africa for the period 1985 to 2016. The first category was the Standardized Precipitation Index (SPI) accumulated over 3-, 6- and 12-months (hereafter of SPI-3, SPI-6 and SPI-12 respectively). The second category consists of the four Drought Monitoring Indicators (DMI) i.e., Drought Duration (DD), Severity (DS), Intensity (DI) and Frequency (DF). Firstly, analysis of SPI-3, SPI-6 and SPI-12 illustrate that between 1985 and 2016, the Western Cape Province experienced recurrent mild drought conditions. This suggests that the drought conditions experienced during 2015/2016 hydrological year (hereafter current) in the Western Cape Province is a manifestation of past drought conditions. Secondly, analysis of trends in DMI series depict a noticeable spatial-temporal dependence wherein the southern and western regions experienced more severe droughts compared to the eastern and northern regions of the Western Cape Province. Results also show that the DMI trends exhibit up to ~8% variability over the past decade. Overall, the current drought conditions in the Western Cape Province continues to adversely affect agricultural production while the water reservoirs are at below 30% capacity implying that the socio-economic impacts of these droughts will continue to reverberate for many months to come. Though the on-going drought conditions in the Western Cape Province is a regular part of nature’s cycle, analysis of historical drought characteristics based on drought indicators is an important first step towards placing the current drought conditions into perspective, and contribute to triggering action and response thereof. All these lay the foundation for drought monitoring and contribute towards the development of drought early warning. Full article
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Open AccessFeature PaperArticle Survey of Heavy Metal Contamination in Water Sources in the Municipality of Torola, El Salvador, through In Situ Sorbent Extraction
Water 2017, 9(11), 877; doi:10.3390/w9110877
Received: 29 September 2017 / Revised: 3 November 2017 / Accepted: 8 November 2017 / Published: 10 November 2017
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Abstract
The presence of heavy metals in water resources directly affects consumer health. The quality of surface water resources in Central America is usually low due to the presence of metals and other pollutants. The lack of analytical instrumentation to perform routine monitoring of
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The presence of heavy metals in water resources directly affects consumer health. The quality of surface water resources in Central America is usually low due to the presence of metals and other pollutants. The lack of analytical instrumentation to perform routine monitoring of water has encouraged the development of easy tools to facilitate the determination of heavy metals in waters in remote sites. In this study, we evaluated the use of different sorbents, such as Adsorbsia As600 (titanium dioxide), Iontosorb Oxin, 8-hydroxyquinoline bearing functional groups, and Duolite GT-73, with thiol functionality, for Cd, Ni, Cu, Zn, and Al extraction. It was found that both Adsorbsia As600 and Iontosorb Oxin allowed the adsorption of all metals, and the recovery was achieved using either HCl or ethylenediaminetetraacetic sodium salt (EDTA) solutions. Hence, Adsorbsia As600 was employed for in situ sampling in the metal contamination evaluation of water samples (from 15 wells and nine storage tanks) from the municipality of Torola, Mozarán, El Salvador. The developed procedure allowed all the metals in the samples to be detected, and Ni and Al were found to be above Salvadoran guidelines for drinking water quality. Full article
(This article belongs to the Special Issue Heavy Metals and Potentially Toxic Elements (PTEs) in Water)
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Open AccessArticle Drought Evolution Due to Climate Change and Links to Precipitation Intensity in the Haihe River Basin
Water 2017, 9(11), 878; doi:10.3390/w9110878
Received: 22 August 2017 / Revised: 30 October 2017 / Accepted: 8 November 2017 / Published: 11 November 2017
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Abstract
Droughts often have a substantial impact on normal socio-economic activities and agricultural production. The Haihe River Basin, one of the primary food production areas in China, has become increasingly sensitive to alternating droughts and floods, and the sharp transitions between them, due to
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Droughts often have a substantial impact on normal socio-economic activities and agricultural production. The Haihe River Basin, one of the primary food production areas in China, has become increasingly sensitive to alternating droughts and floods, and the sharp transitions between them, due to rapid economic development and population growth combined with climate change. In this study, we employ the self-organizing map (SOM) neural network method to perform a cluster analysis on 43 meteorological stations in the study area, dividing the basin into five sub-regions. Then daily precipitation data (1960–2015) are collected, and the number of continuous dry days is used as a drought index to investigate drought evolution trends. Lastly, the Pearson-III curve is used to analyze the first daily precipitation after different drought duration, and the relationships between precipitation intensity, drought duration, and interdecadal drought frequency are observed. The results demonstrate that under the climate warming of the Haihe River Basin, the frequency of droughts increases throughout the whole basin, while the droughts are of shorter duration, the probability of more intense first daily precipitation after droughts increases during the dry–wet transition. The research provides a useful reference for the planning and management of water resources in the Haihe River Basin. Full article
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Open AccessArticle A Combined Hydrological and Hydraulic Model for Flood Prediction in Vietnam Applied to the Huong River Basin as a Test Case Study
Water 2017, 9(11), 879; doi:10.3390/w9110879
Received: 25 September 2017 / Revised: 25 October 2017 / Accepted: 7 November 2017 / Published: 11 November 2017
PDF Full-text (1971 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
A combined hydrological and hydraulic model is presented for flood prediction in Vietnam. This model is applied to the Huong river basin as a test case study. Observed flood flows and water surface levels of the 2002–2005 flood seasons are used for model
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A combined hydrological and hydraulic model is presented for flood prediction in Vietnam. This model is applied to the Huong river basin as a test case study. Observed flood flows and water surface levels of the 2002–2005 flood seasons are used for model calibration, and those of the 2006–2007 flood seasons are used for validation of the model. The physically based distributed hydrologic model WetSpa is used for predicting the generation and propagation of flood flows in the mountainous upper sub-basins, and proves to predict flood flows accurately. The Hydrologic Engineering Center River Analysis System (HEC-RAS) hydraulic model is applied to simulate flood flows and inundation levels in the downstream floodplain, and also proves to predict water levels accurately. The predicted water profiles are used for mapping of inundations in the floodplain. The model may be useful in developing flood forecasting and early warning systems to mitigate losses due to flooding in Vietnam. Full article
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Open AccessArticle Future Projection with an Extreme-Learning Machine and Support Vector Regression of Reference Evapotranspiration in a Mountainous Inland Watershed in North-West China
Water 2017, 9(11), 880; doi:10.3390/w9110880
Received: 14 October 2017 / Revised: 6 November 2017 / Accepted: 6 November 2017 / Published: 11 November 2017
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Abstract
This study aims to project future variability of reference evapotranspiration (ET0) using artificial intelligence methods, constructed with an extreme-learning machine (ELM) and support vector regression (SVR) in a mountainous inland watershed in north-west China. Eight global climate model (GCM) outputs retrieved
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This study aims to project future variability of reference evapotranspiration (ET0) using artificial intelligence methods, constructed with an extreme-learning machine (ELM) and support vector regression (SVR) in a mountainous inland watershed in north-west China. Eight global climate model (GCM) outputs retrieved from the Coupled Model Inter-comparison Project Phase 5 (CMIP5) were employed to downscale monthly ET0 for the historical period 1960–2005 as a validation approach and for the future period 2010–2099 as a projection of ET0 under the Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. The following conclusions can be drawn: the ELM and SVR methods demonstrate a very good performance in estimating Food and Agriculture Organization (FAO)-56 Penman–Monteith ET0. Variation in future ET0 mainly occurs in the spring and autumn seasons, while the summer and winter ET0 changes are moderately small. Annually, the ET0 values were shown to increase at a rate of approximately 7.5 mm, 7.5 mm, 0.0 mm (8.2 mm, 15.0 mm, 15.0 mm) decade−1, respectively, for the near-term projection (2010–2039), mid-term projection (2040–2069), and long-term projection (2070–2099) under the RCP4.5 (RCP8.5) scenario. Compared to the historical period, the relative changes in ET0 were found to be approximately 2%, 5% and 6% (2%, 7% and 13%), during the near, mid- and long-term periods, respectively, under the RCP4.5 (RCP8.5) warming scenarios. In accordance with the analyses, we aver that the opportunity to downscale monthly ET0 with artificial intelligence is useful in practice for water-management policies. Full article
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Open AccessArticle Multi-Level Contact Oxidation Process Performance When Treating Automobile Painting Wastewater: Pollutant Removal Efficiency and Microbial Community Structures
Water 2017, 9(11), 881; doi:10.3390/w9110881
Received: 28 September 2017 / Revised: 29 October 2017 / Accepted: 9 November 2017 / Published: 11 November 2017
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Abstract
This study applied a multi-level contact oxidation process system in a pilot-scale experiment to treat automobile painting wastewater. The experimental wastewater had been pre-treated through a series of physicochemical methods, but the water still contained a high concentration of chemical oxygen demand (COD)
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This study applied a multi-level contact oxidation process system in a pilot-scale experiment to treat automobile painting wastewater. The experimental wastewater had been pre-treated through a series of physicochemical methods, but the water still contained a high concentration of chemical oxygen demand (COD) and had poor biodegradability. After the biological treatment, the COD concentration of effluent could stay below 300 mg/L. The study analyzed the effects of hydraulic residence time (HRT) on COD, ammonia nitrogen (NH4+-N), and total nitrogen (TN). The optimal HRT was 8 h; at that time, removal efficiencies of COD, ammonia nitrogen, and total nitrogen were 83.8%, 86.3%, and 65%, respectively. The system also greatly reduced excess sludge production; the removal efficiency was 82.8% with a HRT of 8 h. The study applied high-throughput pyrosequencing technology to evaluate the microbial diversity and community structures in distinct stages of the biological reactor. The relevance between process performance and microbial community structure was analyzed at the phylum and class level. The abundant Firmicutes made a large contribution to improving the biodegradability of painting wastewater through hydrolysis acidification and reducing sludge production through fermentation in the biological reactor. Full article
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Open AccessArticle Updated Smoothed Particle Hydrodynamics for Simulating Bending and Compression Failure Progress of Ice
Water 2017, 9(11), 882; doi:10.3390/w9110882
Received: 8 September 2017 / Revised: 30 October 2017 / Accepted: 7 November 2017 / Published: 12 November 2017
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Abstract
In this paper, an updated Smoothed Particle Hydrodynamics (SPH) method based on the Simplified Finite Difference Interpolation scheme (SPH_SFDI) is presented to simulate the failure process of ice. The Drucker–Prager model is embedded into the SPH code to simulate the four point bending
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In this paper, an updated Smoothed Particle Hydrodynamics (SPH) method based on the Simplified Finite Difference Interpolation scheme (SPH_SFDI) is presented to simulate the failure process of ice. The Drucker–Prager model is embedded into the SPH code to simulate the four point bending and uniaxial compression failure of ice. The cohesion softening elastic–plastic model is also used in the SPH_SFDI framework. To validate the proposed modeling approach, the numerical results of SPH_SFDI are compared with the standard SPH and the experimental data. The good agreement demonstrated that the proposed SPH_SFDI method including the elastic–plastic cohesion softening Drucker–Prager failure model can provide a useful numerical tool for simulating failure progress of the ice in practical field. It is also shown that the SPH_SFDI can significantly improve the capability and accuracy for simulating ice bending and compression failures as compared with the original SPH scheme. Full article
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Open AccessFeature PaperArticle Integrated Hydrological Model-Based Assessment of Stormwater Management Scenarios in Copenhagen’s First Climate Resilient Neighbourhood Using the Three Point Approach
Water 2017, 9(11), 883; doi:10.3390/w9110883
Received: 14 September 2017 / Revised: 5 November 2017 / Accepted: 8 November 2017 / Published: 12 November 2017
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Abstract
The city of Copenhagen currently pursues a very ambitious plan to make the city ‘cloudburst proof’ within the next 30 years. The cloudburst management plan has the potential to support the city’s aim to become more green, liveable, and sustainable. In this study,
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The city of Copenhagen currently pursues a very ambitious plan to make the city ‘cloudburst proof’ within the next 30 years. The cloudburst management plan has the potential to support the city’s aim to become more green, liveable, and sustainable. In this study, we assessed stormwater system designs using the Three Point Approach (3PA) as a framework, where an indicator value for each domain was calculated using state-of-the-art modelling techniques. We demonstrated the methodology on scenarios representing sequential enhancements of the cloudburst management plan for a district that has been appointed to become the first climate resilient neighbourhood in Copenhagen. The results show that if the cloudburst system is exploited to discharge runoff from selected areas that are disconnected from the combined sewer system, then the plan leads to multiple benefits. These include improved flood protection under a 100-years storm (i.e., compliance with the new demands in domain C of the 3PA), reduced surcharge to terrain under a 10-years storm (i.e., compliance with the service goal in domain B of the 3PA) and an improved yearly water balance (i.e., better performance in domain A of the 3PA). Full article
(This article belongs to the Special Issue Urban Water Cycle Modelling and Management)
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Open AccessArticle Seasonal Water Exchanges between China’s Poyang Lake and Its Saucer-Shaped Depressions on River Deltas
Water 2017, 9(11), 884; doi:10.3390/w9110884
Received: 11 October 2017 / Revised: 9 November 2017 / Accepted: 10 November 2017 / Published: 12 November 2017
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Abstract
The saucer-shaped depressions located at the river deltas of Poyang Lake are typical floodplain shallow sub-lakes subject to river-lake connection or isolation. The hydrological connectivity between these depressions and the main lake has a major influence on the hydrologic function and ecological integrity
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The saucer-shaped depressions located at the river deltas of Poyang Lake are typical floodplain shallow sub-lakes subject to river-lake connection or isolation. The hydrological connectivity between these depressions and the main lake has a major influence on the hydrologic function and ecological integrity of the lake-floodplain and associated wetland habitats. This study explored the water level fluctuations and water exchange processes between the Poyang Lake and three typical saucer-shaped depressions, using a 30-min temporal resolution of water level observations during 2015–2016. Our results showed that the water level correlation and hydrological connectivity between the main lake and its depressions displayed a strong seasonal and spatial signal. Temporally, the rainfall significantly influences the seasonality and frequency of water level fluctuations both in the main lake and the depressions. The correlation coefficient of the water level ordered from high to low occurred during the high-water period, the rising-water period, the falling-water period and the low-water period, respectively. Spatially, depressions with a shorter connection duration to the main lake are located at higher local elevation and at larger geographical distance from the main lake. Finally, we also discussed the implications of these findings and possible factors that could have caused these particular water regime characteristics and water exchange processes. Full article
(This article belongs to the Special Issue Recent Progress in Research on River Deltas)
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Open AccessArticle Modeling of Mixed Crop Field Water Demand and a Smart Irrigation System
Water 2017, 9(11), 885; doi:10.3390/w9110885
Received: 10 September 2017 / Revised: 31 October 2017 / Accepted: 8 November 2017 / Published: 13 November 2017
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Abstract
Taiwan average annual rainfall is approximately 2500 mm. In particular, 80% of the rainfall occurs in summer, and most of the heavy rainfall is caused by typhoons. The situation is worsening as climate change results in uneven rainfall, both in spatial and temporal
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Taiwan average annual rainfall is approximately 2500 mm. In particular, 80% of the rainfall occurs in summer, and most of the heavy rainfall is caused by typhoons. The situation is worsening as climate change results in uneven rainfall, both in spatial and temporal terms. Moreover, climate change has resulted the variations in the seasonal rainfall pattern of Taiwan, thereby aggravating the problem of drought and flooding. The irrigation water distribution system is mostly manually operated, which produces difficulty with regard to the accurate calculation of conveyance losses of channels and fields. Therefore, making agricultural water usage more efficient in the fields and increasing operational accuracy by using modern irrigation systems can ensure appropriate irrigation and sufficient yield during droughts. If agricultural water, which accounts for 70% of the nation’s total water usage, can be allocated more precisely and efficiently, it can improve the efficacy of water resource allocation. In this study, a system dynamic model was used to establish an irrigation water management model for a companion and intercropping field in Central Taiwan. Rainfall and irrigation water were considered for the water supply, and the model simulated two scenarios by reducing 30% and 50% of the planned irrigation water in year 2015. Results indicated that the field storage in the end block of the study area was lower than the wilting point under the 50% reduced irrigation water scenario. The original irrigation plan can be reduced to be more efficient in water usage, and a 50% reduction of irrigation can be applied as a solution of water shortage when drought occurs. However, every block should be irrigated in rotation, by adjusting all water gates more frequently to ensure that the downstream blocks can receive the allocated water to get through the drought event. Full article
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Open AccessCommunication Cadmium and Lead Sorption/Desorption on Non-Amended and By-Product-Amended Soil Samples and Pyritic Material
Water 2017, 9(11), 886; doi:10.3390/w9110886
Received: 28 September 2017 / Revised: 31 October 2017 / Accepted: 8 November 2017 / Published: 13 November 2017
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Abstract
Batch-type experiments were used to study cadmium (Cd) and lead (Pb) sorption/desorption on forest soil, vineyard soil and pyritic material samples, on the by-products mussel shell, oak ash, pine bark and hemp waste, and on forest soil, vineyard soil and pyritic material amended
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Batch-type experiments were used to study cadmium (Cd) and lead (Pb) sorption/desorption on forest soil, vineyard soil and pyritic material samples, on the by-products mussel shell, oak ash, pine bark and hemp waste, and on forest soil, vineyard soil and pyritic material amended with 48 t ha−1 of oak ash, mussel shell, and hemp waste. The main results were that the forest soil showed higher Cd and Pb retention than the vineyard soil and the pyritic material. Regarding the byproducts, sorption was in the following order: oak ash > mussel shell > hemp waste > pine bark, with desorption following an inverse sequence. The pH was the parameter that most influenced Cd and Pb sorption. Cd and Pb sorption curves showed better fitting to the Freundlich than to the Langmuir model, indicating the dominance of multilayer interactions. Oak ash and mussel shell were the amendments causing higher increase in Cd and Pb sorption on both soils and the pyritic material (close to 100% with the oak ash amendment), as well as more a pronounced decrease in desorption. These results could be used to favor an effective management of the by-products studied, which could retain Cd and Pb in soils and degraded areas, preventing water pollution. Full article
(This article belongs to the Special Issue Heavy Metals and Potentially Toxic Elements (PTEs) in Water)
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Open AccessArticle Linkage Analysis of Land Use/Cover Patterns and Hydro-Chemical Characteristics in Different Seasons in Ebinur Lake Watershed, China
Water 2017, 9(11), 888; doi:10.3390/w9110888
Received: 28 September 2017 / Revised: 24 October 2017 / Accepted: 8 November 2017 / Published: 14 November 2017
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Abstract
Ebinur Lake Watershed, with its oases and deserts, is a typically arid and mountainous region on the northern slope of Tianshan Mountains. Along with ever increasing human activities, agricultural and domestic wastes have been directly discharged into river systems around the Watershed, which
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Ebinur Lake Watershed, with its oases and deserts, is a typically arid and mountainous region on the northern slope of Tianshan Mountains. Along with ever increasing human activities, agricultural and domestic wastes have been directly discharged into river systems around the Watershed, which consequently poses a grave threat to the sustainable development of Xinjiang. Through statistical and spatial analysis, we have determined the relationships between land use/cover (LULC) and hydro-chemical characteristics during rainy and dry seasons in 2014. Spatial patterns of hydro-chemical characteristics as demonstrated by mineralization, pH, electrical conductivity (EC), and SO42−, HCO3, Cl, Mg2+, Na+, Ca2+ and K+ concentrations were examined in 113 sites. Since hydro-chemical characteristics were affected by LULC patterns, this study delineated six zones to analyze the distribution characteristics of hydro-chemical parameters and its relationship with LULC patterns. The results showed that, except for the pH, all variables demonstrated significant spatial differences during dry and rainy seasons. In addition, the relationships between water quality and LULC patterns indicated that the farmland, forest–grassland, water body and salinized land all affected hydro-chemical characteristics during both rainy and dry seasons. Especially, decreased rainfall, irrigation, surface runoff, the area of lake, etc. largely led to the increase in ion content, which had great influence on hydro-chemical characteristics parameters in dry season. Furthermore, we established several stepwise linear multiple regressions models. The results showed that pH, mineralization and Ca2+ were defined by forest-grassland, while the Cl and Mg2+ were defined by salinized land during the rainy season. The pH and Na+ were estimated based on farmland, whereas Cl and Ca2+ were estimated based on forest-grassland during the dry season. In conclusion, this research on the relationships between the spatial distribution of hydro-chemical characteristics in Ebinur Lake Watershed and LULC patterns will be significant for the sustainable management of the arid regions in northwest China. Full article
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Open AccessFeature PaperArticle BRISENT: An Entropy-Based Model for Bridge-Pier Scour Estimation under Complex Hydraulic Scenarios
Water 2017, 9(11), 889; doi:10.3390/w9110889
Received: 21 September 2017 / Revised: 6 November 2017 / Accepted: 8 November 2017 / Published: 14 November 2017
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Abstract
The goal of this paper is to introduce the first clear-water scour model based on both the informational entropy concept and the principle of maximum entropy, showing that a variational approach is ideal for describing erosional processes under complex situations. The proposed bridge–pier
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The goal of this paper is to introduce the first clear-water scour model based on both the informational entropy concept and the principle of maximum entropy, showing that a variational approach is ideal for describing erosional processes under complex situations. The proposed bridge–pier scour entropic (BRISENT) model is capable of reproducing the main dynamics of scour depth evolution under steady hydraulic conditions, step-wise hydrographs, and flood waves. For the calibration process, 266 clear-water scour experiments from 20 precedent studies were considered, where the dimensionless parameters varied widely. Simple formulations are proposed to estimate BRISENT’s fitting coefficients, in which the ratio between pier-diameter and sediment-size was the most critical physical characteristic controlling scour model parametrization. A validation process considering highly unsteady and multi-peaked hydrographs was carried out, showing that the proposed BRISENT model reproduces scour evolution with high accuracy. Full article
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Open AccessArticle Reactive Transport Modeling for Mobilization of Arsenic in a Sediment Downgradient from an Iron Permeable Reactive Barrier
Water 2017, 9(11), 890; doi:10.3390/w9110890
Received: 2 October 2017 / Revised: 3 November 2017 / Accepted: 11 November 2017 / Published: 14 November 2017
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Abstract
Arsenic (As) can be naturally present in the native aquifer materials and can be released to groundwater through reduction dissolution of iron oxides containing As. While granular iron permeable reactive barriers (PRBs) can be effective for the treatment of arsenic in groundwater, the
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Arsenic (As) can be naturally present in the native aquifer materials and can be released to groundwater through reduction dissolution of iron oxides containing As. While granular iron permeable reactive barriers (PRBs) can be effective for the treatment of arsenic in groundwater, the mobilization of arsenic in the sediment downgradient of the PRB might be an issue due to the reduced geochemical conditions generated by reactions in the PRB. The release of arsenic in the sediment downgradient from a proposed iron PRB was studied through laboratory column experiments and reactive transport modeling. The laboratory column experiments showed a significant removal of arsenic from the groundwater by granular iron (from the influent concentration of about 0.7 mg L−1 to less than 0.006 mg L−1 at the effluent); however, arsenic can be flushed out from the aquifer sediments (up to 0.09 mg L−1). The reactive transport modeling based on the geochemical reactions as suggested from the experiments, i.e., reductive dissolution of As-bearing goethite, was successful to reproduce the observed geochemical trends in the column experiments. This study can provide implications regarding the installation of iron PRBs to treat arsenic in groundwater and also be useful to understand geochemical behavior of arsenic under reduced conditions. Full article
(This article belongs to the Special Issue Heavy Metals and Potentially Toxic Elements (PTEs) in Water)
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Open AccessArticle Composition of Groundwater Bacterial Communities before and after Air Surging in a Groundwater Heat Pump System According to a Pyrosequencing Assay
Water 2017, 9(11), 891; doi:10.3390/w9110891
Received: 29 September 2017 / Revised: 18 October 2017 / Accepted: 13 November 2017 / Published: 15 November 2017
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Abstract
The geothermal energy of groundwater has aroused increasing interest as a solution to climate change. The groundwater heat pumps (GWHP) system using groundwater is the most environmentally friendly system to date and has been examined in several studies. However, biological clogging by microorganisms
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The geothermal energy of groundwater has aroused increasing interest as a solution to climate change. The groundwater heat pumps (GWHP) system using groundwater is the most environmentally friendly system to date and has been examined in several studies. However, biological clogging by microorganisms negatively affects the thermal efficiency of the GWHP system. In this study, we employed air surging, the most popular among well management methods, and pyrosequencing to analyze the genetic diversity in bacteria before and after air surging in a geothermal well. Furthermore, the diversity of dominant bacterial genera and those related to clogging were evaluated. The bacterial diversity of the groundwater well increased after air surging. Nevertheless, the proportion of bacterial genera thought to be related to microbiological clogging decreased. In cooling and heating systems based on the geothermal energy of groundwater, the wells should be maintained regularly by air surging to reduce efficiency problems caused by microbiological clogging and to prevent secondary damage to human health, e.g., pneumonia due to human pathogenic bacteria including Pseudomonas aeruginosa and Acinetobacter. Full article
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Open AccessArticle Invariants of Turbulence Reynolds Stress and of Dissipation Tensors in Regular Breaking Waves
Water 2017, 9(11), 893; doi:10.3390/w9110893
Received: 30 September 2017 / Revised: 30 October 2017 / Accepted: 10 November 2017 / Published: 16 November 2017
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Abstract
A series of measurements in a flume with a particle-tracking system in three dimensions applied to breaking waves is used to analyse the structure of turbulence with a full set of variables that usually are available only in numerical simulations. After extracting turbulence,
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A series of measurements in a flume with a particle-tracking system in three dimensions applied to breaking waves is used to analyse the structure of turbulence with a full set of variables that usually are available only in numerical simulations. After extracting turbulence, in addition to the standard analysis aiming to quantify the fluxes, i.e., the time-average and the phase-average levels of turbulence and vorticity (details are given in two former papers), a more in-depth description of the structure of turbulence Reynolds stress tensor is given, focussing on the invariants evolution in time and in the vertical. A relation between the components of the Reynolds stress tensor and of the dissipation tensor is depicted. This relation is finalised to possible models of turbulence in breaking waves. Full article
(This article belongs to the Special Issue Turbulence in River and Maritime Hydraulics)
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Open AccessArticle Contamination Event Detection Method Using Multi-Stations Temporal-Spatial Information Based on Bayesian Network in Water Distribution Systems
Water 2017, 9(11), 894; doi:10.3390/w9110894
Received: 13 October 2017 / Revised: 13 November 2017 / Accepted: 14 November 2017 / Published: 16 November 2017
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Abstract
As a core part of protecting water quality safety in water distribution systems, contamination event detection requires high accuracy. Previously, temporal analysis-based methods for single sensor stations have shown limited performance as they fail to consider spatial information. Besides, abundant historical data from
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As a core part of protecting water quality safety in water distribution systems, contamination event detection requires high accuracy. Previously, temporal analysis-based methods for single sensor stations have shown limited performance as they fail to consider spatial information. Besides, abundant historical data from multiple stations are still underexploited in causal relationship modelling. In this paper, a contamination event detection method is proposed, in which both temporal and spatial information from multi-stations in water distribution systems are used. The causal relationship between upstream and downstream stations is modelled by Bayesian Network, using the historical water quality data and hydraulic data. Then, the spatial abnormal probability for one station is obtained by comparing its current causal relationship with the established model. Meanwhile, temporal abnormal probability is obtained by conventional methods, such as an Autoregressive (AR) or threshold model for the same station. The integrated probability that is calculated employed temporal and spatial probabilities using Logistic Regression to determine the final detection result. The proposed method is tested over two networks and its detection performance is evaluated against results obtained from traditional methods using only temporal analysis. Results indicate that the proposed method shows higher accuracy due to its increased information from both temporal and spatial dimensions. Full article
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Open AccessFeature PaperArticle Effect of Water Quality Sampling Approaches on Nitrate Load Predictions of a Prominent Regression-Based Model
Water 2017, 9(11), 895; doi:10.3390/w9110895
Received: 5 October 2017 / Revised: 27 October 2017 / Accepted: 6 November 2017 / Published: 16 November 2017
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Abstract
High frequency in-situ measurements of nitrate can greatly reduce uncertainty in nitrate flux estimates. Water quality databases maintained by various federal and state agencies often consist of pollutant concentration data obtained from periodic grab samples collected from gauged reaches of a stream. Regression
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High frequency in-situ measurements of nitrate can greatly reduce uncertainty in nitrate flux estimates. Water quality databases maintained by various federal and state agencies often consist of pollutant concentration data obtained from periodic grab samples collected from gauged reaches of a stream. Regression models, such as the LOAD ESTimator (LOADEST), are frequently used to model variations in concentrations associated with changes in water discharge to provide integrated solute flux measurements. However, uncertainty in the relationships between nutrient concentration and flow may lead to errors in the corresponding flux estimates. In this study, a high frequency, in-situ measurement of nitrate concentration was implemented to ascertain uncertainty in the concentration/discharge relationship caused by nitrate hysteresis. It was found that observed nitrate hysteresis, as influenced by complex storm/watershed interactions, was not readily predictable. Therefore, it can lead to substantial nitrate flux uncertainty, based on periodic grab sample monitoring approaches. Scientists and engineers should take advantage of the proposed findings in future studies to enhance the quality of the associated decision making processes. Full article
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Open AccessFeature PaperArticle Quality of Roof-Harvested Rainwater as a Function of Environmental and Air Pollution Factors in a Coastal Mediterranean City (Haifa, Israel)
Water 2017, 9(11), 896; doi:10.3390/w9110896
Received: 30 September 2017 / Revised: 6 November 2017 / Accepted: 13 November 2017 / Published: 16 November 2017
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Abstract
The quality of roof-harvested rainwater in a Mediterranean climate, which is characterised by dry summers and erratic wet winters, was studied. The effects of environmental factors (rain depth, length of dry period between consecutive rain events, time since the beginning of the rainy
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The quality of roof-harvested rainwater in a Mediterranean climate, which is characterised by dry summers and erratic wet winters, was studied. The effects of environmental factors (rain depth, length of dry period between consecutive rain events, time since the beginning of the rainy season, roof type, wind speed, and wind direction) and air pollution parameters (O3, SO2, NO2, NO, PM2.5, and PM2.5–10) on roof runoff quality were studied. Three roofs of three common types (concrete, steel sheets, and tiles) were constructed. Roof-generated runoff was collected over two rainy seasons (>50 rain events) and were analysed for presence of metals, chemical and physical constituents, and faecal coliforms (a total of 23 parameters). Rain depth and runoff volume from each roof were recorded for each rain event. Most parameters examined complied with the Israeli potable water regulations. A stepwise multivariate linear regression established a significant effect of roof type on runoff pollutant concentrations, especially for ones generated by the roof material itself (e.g., Ca from the concrete roof and Zn from roof tiles). A significant effect of various air pollutants on the quality of roof-runoff water was found, as explained by rain washing off pollutants that accumulated in the atmosphere during the antecedent dry period. Both O3 and PM2.5–10 affected 17 quality parameters each. Rain depth affected only four out of the 23 water quality variables. In contrast, the length of the dry period between consecutive rain events was an important factor, affecting 12 roof-runoff quality variables. Full article
(This article belongs to the Special Issue Advances on Urban Stormwater Harvesting Strategies)
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Open AccessArticle Effects of Permafrost Degradation on the Hydrological Regime in the Source Regions of the Yangtze and Yellow Rivers, China
Water 2017, 9(11), 897; doi:10.3390/w9110897
Received: 22 July 2017 / Revised: 12 October 2017 / Accepted: 10 November 2017 / Published: 16 November 2017
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Abstract
Climate warming has intensified permafrost degradation, which could have a variety of implications on the hydrological regime in permafrost regions. In this study, we analyzed the effects of permafrost degradation on the hydrological regime via four hydrological variables for 10 unregulated catchments in
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Climate warming has intensified permafrost degradation, which could have a variety of implications on the hydrological regime in permafrost regions. In this study, we analyzed the effects of permafrost degradation on the hydrological regime via four hydrological variables for 10 unregulated catchments in the source regions of the Yangtze and Yellow rivers. The results demonstrate that catchments with high permafrost coverage are expected to have an increased winter discharge ratio (proportion of winter discharge contribution to total annual flow), a decreased recession coefficient and a decreased ratio of Qmax/Qmin due to permafrost degradation. However, the great storage effects of lakes and wetlands, which could contribute to more groundwater instead of direct surface discharge, may affect the hydrological effects of permafrost degradation and result in the abnormal performance at catchment scale. The correlation analysis between summer precipitation (July–September) and the following winter discharge (December–February) indicates that permafrost degradation may affect the redistribution of summer precipitation towards the following winter discharge via increasing the soil storage capacity and delaying the release of water into streams in permafrost regions. However, unlike the Arctic and sub-Arctic regions, no significant changes for the hydrological regime (four hydrological variables) are detected over the individual periods of records for each catchment. Decreased precipitation in summer seems to reduce the water infiltration to supply the groundwater, which weakens the effects of permafrost degradation on the hydrological regime. This study implies that the storage effects of lakes and wetlands and the changes of summer precipitation patterns should be considered in future permafrost hydrological simulations, which have suggested that a large increase in groundwater discharge to streams will likely occur in response to permafrost degradation due to the warming climate in the ideal scenario. Full article
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Open AccessArticle Development of a Predictive Tool to Support Environmentally Sustainable Management in Port Basins
Water 2017, 9(11), 898; doi:10.3390/w9110898
Received: 28 September 2017 / Revised: 10 November 2017 / Accepted: 15 November 2017 / Published: 18 November 2017
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Abstract
According to the Water Framework Directive, harbours that are classified as heavily modified water bodies must either reach or maintain good ecological potential. Moreover, following the marine spatial planning principles, the effects of port structure changes on water quality must also be considered.
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According to the Water Framework Directive, harbours that are classified as heavily modified water bodies must either reach or maintain good ecological potential. Moreover, following the marine spatial planning principles, the effects of port structure changes on water quality must also be considered. To support the sustainable management of harbour waters, we calculated flushing time (FT) through the use of a numerical model within the Civitavecchia port under different scenarios. To assess the effects of the realization of new infrastructure that will significantly alter the port configuration in the coming years, we also developed the flushing efficiency index (FEI). The increase in the harbour basin size due to the embankment extension result in high values of FT, particularly in the inner part of the port, in accordance with the highest values of the enrichment factor of the trace metals found in the sediment. The deterioration of water quality is confirmed by negative FEI values. Otherwise, the index assumes positive values after the realization of a second entrance in the southern part of Civitavecchia port, highlighting a drastic improvement in harbour water renewal. This study provides a low-cost and predictive tool to correctly address environmentally sustainable management of port activities. Full article
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Open AccessArticle Winter Snow Level Rise in the Northern Sierra Nevada from 2008 to 2017
Water 2017, 9(11), 899; doi:10.3390/w9110899
Received: 10 October 2017 / Revised: 14 November 2017 / Accepted: 15 November 2017 / Published: 18 November 2017
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Abstract
The partitioning of precipitation into frozen and liquid components influences snow-derived water resources and flood hazards in mountain environments. We used a 915-MHz Doppler radar wind profiler upstream of the northern Sierra Nevada to estimate the hourly elevation where snow melts to rain,
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The partitioning of precipitation into frozen and liquid components influences snow-derived water resources and flood hazards in mountain environments. We used a 915-MHz Doppler radar wind profiler upstream of the northern Sierra Nevada to estimate the hourly elevation where snow melts to rain, or the snow level, during winter (December–February) precipitation events spanning water years (WY) 2008–2017. During this ten-year period, a Mann-Kendall test indicated a significant (p < 0.001) positive trend in snow level with a Thiel-Sen slope of 72 m year−1. We estimated total precipitation falling as snow (snow fraction) between WY1951 and 2017 using nine daily mid-elevation (1200–2000 m) climate stations and two hourly stations spanning WY2008–2017. The climate-station-based snow fraction estimates agreed well with snow-level radar values (R2 = 0.95, p < 0.01), indicating that snow fractions represent a reasonable method to estimate changes in frozen precipitation. Snow fraction significantly (p < 0.001) declined during WY2008–2017 at a rate of 0.035 (3.5%) year−1. Single-point correlations between detrended snow fraction and sea-surface temperatures (SST) suggested that positive SST anomalies along the California coast favor liquid phase precipitation during winter. Reanalysis-derived integrated moisture transported upstream of the northern Sierra Nevada was negatively correlated with snow fraction (R2 = 0.90, p < 0.01), with atmospheric rivers representing the likely circulation mechanism producing low-snow-fraction storms. Full article
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Open AccessArticle Three-Dimensional Numerical Study of Free-Flow Sediment Flushing to Increase the Flushing Efficiency: A Case-Study Reservoir in Japan
Water 2017, 9(11), 900; doi:10.3390/w9110900
Received: 12 October 2017 / Revised: 10 November 2017 / Accepted: 14 November 2017 / Published: 19 November 2017
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Abstract
The catchment of the Dashidaira reservoir located on the Kurobe River has high sediment yield. Because of the sufficient available amount of water in the catchment during flood events, the free-flow sediment flushing operation with full water-level drawdown is employed every year to
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The catchment of the Dashidaira reservoir located on the Kurobe River has high sediment yield. Because of the sufficient available amount of water in the catchment during flood events, the free-flow sediment flushing operation with full water-level drawdown is employed every year to preserve the effective storage capacity of the Dashidaira reservoir. This paper focuses first on the numerical simulation of a previously conducted free-flow flushing operation in the Dashidaira reservoir using the available in situ obtained data. Afterwards, to improve the flushing efficiency, the effects of water and discharge manipulation and the construction of an auxiliary channel on the total volume of the flushed sediment were studied. A fully 3D numerical model using the finite volume approach in combination with a wetting/drying algorithm was utilized to reproduce the flow velocity field and simulate the movable bed variations. The outcomes revealed that increasing the average free-flow discharge during the free-flow stage by approximately 56%, in the form of multiple discharge pulses, can enhance the flushing efficiency by up to 13%, and the construction of an auxiliary channel in the wide midstream of the reservoir can locally increase the sediment erosion from this area. Full article
(This article belongs to the Special Issue Adaptive Catchment Management and Reservoir Operation)
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Open AccessArticle On the Dominant Factor Controlling Seasonal Hydrological Forecast Skill in China
Water 2017, 9(11), 902; doi:10.3390/w9110902
Received: 11 September 2017 / Revised: 12 November 2017 / Accepted: 16 November 2017 / Published: 20 November 2017
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Abstract
Initial conditions (ICs) and climate forecasts (CFs) are the two primary sources of seasonal hydrological forecast skill. However, their relative contribution to predictive skill remains unclear in China. In this study, we investigate the relative roles of ICs and CFs in cumulative runoff
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Initial conditions (ICs) and climate forecasts (CFs) are the two primary sources of seasonal hydrological forecast skill. However, their relative contribution to predictive skill remains unclear in China. In this study, we investigate the relative roles of ICs and CFs in cumulative runoff (CR) and soil moisture (SM) forecasts using 31-year (1980–2010) ensemble streamflow prediction (ESP) and reverse-ESP (revESP) simulations with the Variable Capacity Infiltration (VIC) hydrologic model. The results show that the relative importance of ICs and CFs largely depends on climate regimes. The influence of ICs is stronger in a dry or wet-to-dry climate regime that covers the northern and western interior regions during the late fall to early summer. In particular, ICs may dominate the forecast skill for up to three months or even six months during late fall and winter months, probably due to the low precipitation value and variability in the dry period. In contrast, CFs become more important for most of southern China or during summer months. The impact of ICs on SM forecasts tends to cover larger domains than on CR forecasts. These findings will greatly benefit future work that will target efforts towards improving current forecast levels for the particular regions and forecast periods. Full article
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