Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
5.8
3.0
Journals
Water
Editor’s Choice
water-logo

Journal Menu

► Journal Menu

Journal Browser

► Journal Browser
share announcement

Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

Order results
Result details
Results per page
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
18 pages, 5312 KiB  
Article
Flooding Urban Landscapes: Analysis Using Combined Hydrodynamic and Hydrologic Modeling Approaches
by Manoj K. Jha and Sayma Afreen
Water 2020, 12(7), 1986; https://doi.org/10.3390/w12071986 - 14 Jul 2020
Cited by 22 | Viewed by 4279
Abstract
The frequency and severity of floods have been found to increase in recent decades, which have adverse effects on the environment, economics, and human lives. The catastrophe of such floods can be confronted with the advance prediction of floods and reliable analyses methods. [...] Read more.
The frequency and severity of floods have been found to increase in recent decades, which have adverse effects on the environment, economics, and human lives. The catastrophe of such floods can be confronted with the advance prediction of floods and reliable analyses methods. This study developed a combined flood modeling system for the prediction of floods, and analysis of associated vulnerabilities on urban infrastructures. The application of the method was tested on the Blue River urban watershed in Missouri, USA, a watershed of historical significance for flood impacts and abundance of data availability for such analyses. The combined modeling system included two models: hydrodynamic model HEC-RAS (Hydrologic Engineering Center—River Analysis System) and hydrologic model SWAT (Soil and Water Assessment Tool). The SWAT model was developed for the watershed to predict time-series hydrograph data at desired locations, followed by the setup of HEC-RAS model for the analysis and prediction of flood extent. Both models were calibrated and validated independently using the observed data. The well-calibrated modeling setup was used to assess the extent of impacts of the hazard by identifying the flood risk zones and threatened critical infrastructures in flood zones through inundation mapping. Results demonstrate the usefulness of such combined modeling systems to predict the extent of flood inundation and thus support analyses of management strategies to deal with the risks associated with critical infrastructures in an urban setting. This approach will ultimately help with the integration of flood risk assessment information in the urban planning process. Full article
(This article belongs to the Special Issue Impacts of Landscape Change on Water Resources)
►▼ Show Figures

Figure 1

18 pages, 15342 KiB  
Article
Efficient Urban Inundation Model for Live Flood Forecasting with Cellular Automata and Motion Cost Fields
by Maikel Issermann, Fi-John Chang and Haifeng Jia
Water 2020, 12(7), 1997; https://doi.org/10.3390/w12071997 - 14 Jul 2020
Cited by 7 | Viewed by 2985
Abstract
The mitigation of societal damage from urban floods requires fast hydraulic models for emergency and planning purposes. The simplified mathematical model Cellular Automata is combined with Motion Cost fields, which score the difficulty to traverse an area, to the urban inundation model CAMC. [...] Read more.
The mitigation of societal damage from urban floods requires fast hydraulic models for emergency and planning purposes. The simplified mathematical model Cellular Automata is combined with Motion Cost fields, which score the difficulty to traverse an area, to the urban inundation model CAMC. It is implemented with simple matrix and logic operations to achieve high computational efficiency. The development concentrated on an application in dense urban built-up areas with numerous buildings. CAMC is efficient and flexible enough to be used in a “live” urban flood warning system with current weather conditions. A case study is conducted in the German city of Wuppertal with about 12,000 buildings. The water depth estimation of every time step are visualized in a web-interface on the basis of the virtual globe NASA WorldWind. CAMC is compared with the shallow water equations-based model ANUGA. CAMC is approximatively 5 times faster than ANUGA at high spatial resolution and able to maintain numerical stability. The Nash-Sutcliffe coefficient (0.61), Root Mean Square Error (0.39 m) and Index of Agreement (0.65) indicate acceptable agreement for water depth estimation but identify different areas where important deviations occur. The estimation of velocity performs considerably less well (0.34 for Nash-Sutcliffe coefficient, 0.13 ms − 1 for Root Mean Square Error, and 0.39 for Index of Agreement) because CA ignores momentum conservation. Full article
(This article belongs to the Special Issue Research on Mathematical Models of Floods)
►▼ Show Figures

Figure 1

23 pages, 5860 KiB  
Article
Sedimentological, Mineralogical and Geochemical Features of Late Quaternary Sediment Profiles from the Southern Tuscany Hg Mercury District (Italy): Evidence for the Presence of Pre-Industrial Mercury and Arsenic Concentrations
by Francesca Pasquetti, Orlando Vaselli, Giovanni Zanchetta, Barbara Nisi, Marco Lezzerini, Monica Bini and Daniela Mele
Water 2020, 12(7), 1998; https://doi.org/10.3390/w12071998 - 14 Jul 2020
Cited by 7 | Viewed by 3546
Abstract
Southern Tuscany (Italy) is an important metallogenic district that hosts relevant S-polymetallic deposits that have intensely been exploited for centuries. Consequently, potential toxic elements, such as Hg and As, are widely distributed in the surrounding environment. In this paper, an extensive sedimentological, mineralogical [...] Read more.
Southern Tuscany (Italy) is an important metallogenic district that hosts relevant S-polymetallic deposits that have intensely been exploited for centuries. Consequently, potential toxic elements, such as Hg and As, are widely distributed in the surrounding environment. In this paper, an extensive sedimentological, mineralogical and geochemical study of two Late Quaternary sediment profiles, partially outcropping along the coast of southern Tuscany (Ansedonia area), was carried out to evaluate the contents and mobility of Hg and As with the aims to contribute to the definition of the geochemical baseline of southern Tuscany before the human intervention and evaluate the potential dispersion of these harmful elements. The sedimentological, mineralogical and geochemical (major elements) features revealed that the studied profiles are mostly related to the local geological characteristics and the Quaternary geological history of the area. The concentrations and the normalized patterns of trace and rare earth elements highlighted the absence of any anthropogenic activity. This implies that the studied samples are to be regarded as good proxies for evaluating the geochemical baseline of southern Tuscany before the intense mining activity. The enrichment factors (EF) of most trace elements were indeed lower or close to 2, indicating a variability close to the average concentration of the Upper Continental Crust (UCC), while other elements slightly enriched, such as Pb, were in agreement with the natural baseline reported for southern Tuscany. Mercury and As displayed EF values >40 when compared to the average contents of UCC, although they decrease down to 4 when compared to the suggested baseline for southern Tuscany. The higher Hg and As contents detected in this study, inferred to natural sources, evidenced (i) the great natural variability occurring in largely mineralized areas and (ii) the importance of estimating reference environmental parameters in order to avoid misleading interpretations of the detected anomalies. Moreover, the results of leaching test on sediment samples denoted a relatively low mobility of Hg and As, suggesting that these elements are preferentially mobilized by transport of clastic sediments and such anomalies may be preserved for relatively long times in Quaternary sediments. However, leachable Hg (0.6–9.7 μg/L) and As (2.1–42.2 μg/L) concentrations are significantly high when compared to those of the Italian limit for groundwater (1 µg/L for Hg and 10 µg/L for As). Quaternary sediments from southern Tuscany could then be a potential, though natural, source of Hg and As to groundwater systems. Full article
(This article belongs to the Special Issue Climate Change and Anthropogenic Impact on Coastal Environments)
►▼ Show Figures

Figure 1

17 pages, 4145 KiB  
Article
Interannual and Seasonal Shift between Microcystis and Dolichospermum: A 7-Year Investigation in Lake Chaohu, China
by Min Zhang, Zhen Yang, Yang Yu and Xiaoli Shi
Water 2020, 12(7), 1978; https://doi.org/10.3390/w12071978 - 13 Jul 2020
Cited by 24 | Viewed by 2863
Abstract
The shifts among bloom-forming cyanobacteria have attracted increasing attention due to the reductions in nitrogen and phosphorus during the eutrophication mitigation process. However, knowledge is limited regarding the pattern and drivers of the shifts among these cyanobacterial genera. In this study, we performed [...] Read more.
The shifts among bloom-forming cyanobacteria have attracted increasing attention due to the reductions in nitrogen and phosphorus during the eutrophication mitigation process. However, knowledge is limited regarding the pattern and drivers of the shifts among these cyanobacterial genera. In this study, we performed a 7-year long, monthly investigation in Lake Chaohu, to analyze the interannual and seasonal shifts between Microcystis and Dolichospermum. Our results showed that Microcystis was the dominant cyanobacterium in the western lake region in summer, whereas Dolichospermum was dominant in the other regions and seasons. The Microcystis biomass and ratio were driven primarily by total phosphorus and temperature. The sensitivity of Dolichospermum to nutrients and temperature was relatively weak compared to that of Microcystis. The shifts between Microcystis and Dolichospermum might be led by Microcystis. If the temperature and phosphorus level were relatively high, then Microcystis grew rapidly, and competitively excluded Dolichospermum. If the nutrient level, especially the phosphorus level, was low, then the exclusive power of Microcystis was weak, and Dolichospermum maintained its dominance, even in summer. The key temperature (~17 °C) determined the dominance of the two cyanobacteria. Microcystis never dominated, while Dolichospermum was always dominant below the key temperature. Microcystis and Dolichospermum had different means of responding to the interaction of temperature, nitrogen and phosphorus. The Dolichospermum biomass was sensitive to the variation in nitrogen level, and the sensitivity depended on temperature. While the Microcystis biomass was sensitive to the variation in phosphorus level, and the sensitivity depended on temperature and total nitrogen. The different ways might contribute to the succession of the two cyanobacteria. Our findings will be helpful for improving the understanding of the shift process between Microcystis and Dolichospermum. Full article
(This article belongs to the Special Issue Effects of Harmful Cyanobacteria on Ecosystem Functioning, Food Webs, and Water Quality)
►▼ Show Figures

Figure 1

19 pages, 1558 KiB  
Review
What’s in a Name? Patterns, Trends, and Suggestions for Defining Non-Perennial Rivers and Streams
by Michelle H. Busch, Katie H. Costigan, Ken M. Fritz, Thibault Datry, Corey A. Krabbenhoft, John C. Hammond, Margaret Zimmer, Julian D. Olden, Ryan M. Burrows, Walter K. Dodds, Kate S. Boersma, Margaret Shanafield, Stephanie K. Kampf, Meryl C. Mims, Michael T. Bogan, Adam S. Ward, Mariana Perez Rocha, Sarah Godsey, George H. Allen, Joanna R. Blaszczak, C. Nathan Jones and Daniel C. Allenadd Show full author list remove Hide full author list
Water 2020, 12(7), 1980; https://doi.org/10.3390/w12071980 - 13 Jul 2020
Cited by 62 | Viewed by 9198
Abstract
Rivers that cease to flow are globally prevalent. Although many epithets have been used for these rivers, a consensus on terminology has not yet been reached. Doing so would facilitate a marked increase in interdisciplinary interest as well as critical need for clear [...] Read more.
Rivers that cease to flow are globally prevalent. Although many epithets have been used for these rivers, a consensus on terminology has not yet been reached. Doing so would facilitate a marked increase in interdisciplinary interest as well as critical need for clear regulations. Here we reviewed literature from Web of Science database searches of 12 epithets to learn (Objective 1—O1) if epithet topics are consistent across Web of Science categories using latent Dirichlet allocation topic modeling. We also analyzed publication rates and topics over time to (O2) assess changes in epithet use. We compiled literature definitions to (O3) identify how epithets have been delineated and, lastly, suggest universal terms and definitions. We found a lack of consensus in epithet use between and among various fields. We also found that epithet usage has changed over time, as research focus has shifted from description to modeling. We conclude that multiple epithets are redundant. We offer specific definitions for three epithets (non-perennial, intermittent, and ephemeral) to guide consensus on epithet use. Limiting the number of epithets used in non-perennial river research can facilitate more effective communication among research fields and provide clear guidelines for writing regulatory documents. Full article
(This article belongs to the Special Issue Hydrology, Geomorphology, and Ecology of Intermittent Rivers and Streams)
►▼ Show Figures

Figure 1

27 pages, 5681 KiB  
Article
Regional Isotopic Signatures of Groundwater in Croatia
by Željka Brkić, Mladen Kuhta, Tamara Hunjak and Ozren Larva
Water 2020, 12(7), 1983; https://doi.org/10.3390/w12071983 - 13 Jul 2020
Cited by 17 | Viewed by 4279
Abstract
Tracer methods are useful for investigating groundwater travel times and recharge rates and analysing impacts on groundwater quality. The most frequently used tracers are stable isotopes and tritium. Stable isotopes of oxygen (δ18O) and hydrogen (δ2H) are [...] Read more.
Tracer methods are useful for investigating groundwater travel times and recharge rates and analysing impacts on groundwater quality. The most frequently used tracers are stable isotopes and tritium. Stable isotopes of oxygen (δ18O) and hydrogen (δ2H) are mainly used as indicators of the recharge condition. Tritium (3H) is used to estimate an approximate mean groundwater age. This paper presents the results of an analysis of stable isotope data and tritium activity in Croatian groundwater samples that were collected between 1997 and 2014 at approximately 100 sites. The composition of the stable isotopes of groundwater in Croatia originates from recent precipitation and is described using two regional groundwater lines. One of them is applied to groundwater accumulated in the aquifers in the Pannonian part of Croatia and the other is for groundwater accumulated in the Dinaric karst of Croatia. The isotope content shows that the studied groundwater is mainly modern water. A mix of sub-modern and modern water is mostly accumulated in semi-confined porous aquifers in northern Croatia, deep carbonate aquifers, and (sub)thermal springs. Full article
(This article belongs to the Special Issue Application of Stable Isotopes and Tritium in Hydrology)
►▼ Show Figures

Figure 1

21 pages, 1897 KiB  
Article
Models of Subsidies for Water and Sanitation Services for Vulnerable People in South American Countries: Lessons for Brazil
by Daniel Antonio Narzetti and Rui Cunha Marques
Water 2020, 12(7), 1976; https://doi.org/10.3390/w12071976 - 13 Jul 2020
Cited by 16 | Viewed by 5518
Abstract
Access to water and sanitation services (WSS) in developing countries is constrained by the conditions of social inequality and the services affordability for the poorest households. Therefore, public policies related to WSS need to broaden in scope given the challenge of reaching all [...] Read more.
Access to water and sanitation services (WSS) in developing countries is constrained by the conditions of social inequality and the services affordability for the poorest households. Therefore, public policies related to WSS need to broaden in scope given the challenge of reaching all customers, especially the most vulnerable, in order to achieve a balance between the social and financial objectives of WSS. This paper will contribute to the understanding of the main access and subsidy policies in South American countries focusing on the Brazilian case study. The different experiences in this region have provided some interesting lessons about these issues for Brazil; the conclusion is that the current indirect and cross-subsidy policies are important, but the needed practices for expanding pro-poor access require direct demand-side subsidies. A more proactive intervention through public authorities is also needed. A new subsidization model for Brazil is highlighted and discussed. Full article
(This article belongs to the Collection Water Policy Collection)
►▼ Show Figures

Figure 1

15 pages, 1519 KiB  
Article
A Stakeholder Analysis for a Water-Energy-Food Nexus Evaluation in an Atlantic Forest Area: Implications for an Integrated Assessment and a Participatory Approach
by Giacomo Melloni, Ana Paula Dias Turetta, Michelle Bonatti and Stefan Sieber
Water 2020, 12(7), 1977; https://doi.org/10.3390/w12071977 - 13 Jul 2020
Cited by 19 | Viewed by 4492
Abstract
A water-energy-food (WEF) nexus assessment supports natural resource management by providing an integrated framework for evaluation and decision-making. The participation of a wide range of stakeholders is essential for achieving environmental, economic, and social sustainability in this framework. This analysis supports the decision-making [...] Read more.
A water-energy-food (WEF) nexus assessment supports natural resource management by providing an integrated framework for evaluation and decision-making. The participation of a wide range of stakeholders is essential for achieving environmental, economic, and social sustainability in this framework. This analysis supports the decision-making process of the nexus assessment by facilitating dialogue between stakeholders in order to achieve long term efficiencies, especially in rural landscapes where most of the services connected to WEF securities are provided. We identify the most relevant stakeholders operating in the connection between agricultural practices and the WEF nexus to stimulate their engagement in the nexus governance. The study area was the Atlantic Forest Reserve of Ribeirão das Lajes, Brazil. A stakeholder analysis, generating qualitative data using snowball sampling interviews was applied and, after the identification of stakeholders, an analytical categorization disclosing potential conflicts among them was performed. We obtained a pool of stakeholders from different organizational types, including a large number of public entities at local and state levels. The main threat to the development of the project is considered to be the lack of communication between the parties. We note that the prior identification of this group of stakeholders facilitates this communication, enhancing social representation in the area. Outcomes of this study demonstrate the relevance of stakeholder analysis in nexus governance for integrated natural resource management. Full article
(This article belongs to the Section Water Resources Management, Policy and Governance)
►▼ Show Figures

Figure 1

23 pages, 5748 KiB  
Article
Analysis of the Evolution of Drought, Flood, and Drought-Flood Abrupt Alternation Events under Climate Change Using the Daily SWAP Index
by Ying Zhao, Zhaohui Weng, Hua Chen and Jiawei Yang
Water 2020, 12(7), 1969; https://doi.org/10.3390/w12071969 - 12 Jul 2020
Cited by 42 | Viewed by 5743
Abstract
With the increase of drought and flood frequency, the drought-flood abrupt alternation events occur frequently. Due to the coexistence and rapid transformation of drought and flood, the drought-flood abrupt alternation events is often more harmful and threatening than the single drought or flood [...] Read more.
With the increase of drought and flood frequency, the drought-flood abrupt alternation events occur frequently. Due to the coexistence and rapid transformation of drought and flood, the drought-flood abrupt alternation events is often more harmful and threatening than the single drought or flood event to the security of the society. This study is to synthetically evaluate the evolving characteristics of drought, flood, and drought-flood abrupt alternation events under climate change, which are identified by using the Standard Weighted Average Precipitation (SWAP) index. The variability of drought, flood, and drought-flood abrupt alternation events in the future is predicted by using GCM projections, whose outputs are corrected by using a daily bias correction method. The results show that: (1) The SWAP index has the capability to judge reliably the onset, duration, and intensity over the study areas, and can be used to monitor drought-flood abrupt alternation events efficiently; (2) In the reference period (1961–2005), for the drought-flood abrupt alternation events, the frequency has a downward trend in the upper reaches and an upward trend in the lower reaches, and the spatial distribution of intensity shows a contrary law to that of frequency; (3) The frequency and intensity of drought-flood abrupt alternation events show an upward trend in the whole basin in the future period (2021–2095), under the RCP4.5 and RCP8.5 scenarios. These results indicate that drought-flood abrupt alternation events can be more frequent, and the intensity will significantly increase in the 21st century, which may likely pose a serious impact on this basin. Full article
(This article belongs to the Special Issue Global Changes in Drought Frequency and Severity)
►▼ Show Figures

Figure 1

18 pages, 3224 KiB  
Article
Urbanization—Its Hidden Impact on Water Losses: Prądnik River Basin, Lesser Poland
by Tomáš Lepeška, Jakub Wojkowski, Andrzej Wałęga, Dariusz Młyński, Artur Radecki-Pawlik and Branislav Olah
Water 2020, 12(7), 1958; https://doi.org/10.3390/w12071958 - 10 Jul 2020
Cited by 18 | Viewed by 3243
Abstract
Urban development causes multiple water losses. Some of them may be ignored but some could have a huge influence on the whole catchment, including soil drought. As urban sprawl rises, space for unaffected infiltration and retention is increasingly limited. The objective of this [...] Read more.
Urban development causes multiple water losses. Some of them may be ignored but some could have a huge influence on the whole catchment, including soil drought. As urban sprawl rises, space for unaffected infiltration and retention is increasingly limited. The objective of this study was to backcast and to estimate water-retention loss due to urbanization during the period of 1990–2018. We used landcover data, meteorological and hydrological data and data on soil water-holding capacity. Water-retention loss was expressed as soil water retention capacity loss, net precipitation loss and total sum of precipitation loss. Historical change in urban extension has led to large impacts on the hydrological cycle of the study area. Progressive urban development caused water-retention losses which range from 3.380 to 14.182 millions of cubic meters—depending on the methodology used. Hydrological analysis showed the lack of a significant trend (decrease trend) of low flow which is caused by the high percentage of natural land use in the upper part of catchment. Our results show that backcasting of water retention change using CLC data (a) brings new and plausible data on retention loss, (b) is possible to replicate and (c) data used are common and easy-to-get. Full article
(This article belongs to the Special Issue Hydrological Impacts of Climate Change and Land Use)
►▼ Show Figures

Figure 1

28 pages, 4996 KiB  
Article
Improvement of SCS-CN Initial Abstraction Coefficient in the Czech Republic: A Study of Five Catchments
by Martin Caletka, Monika Šulc Michalková, Petr Karásek and Petr Fučík
Water 2020, 12(7), 1964; https://doi.org/10.3390/w12071964 - 10 Jul 2020
Cited by 36 | Viewed by 4560
Abstract
The SCS-CN method is a globally known procedure used primarily for direct-runoff estimates. It also is integrated in many modelling applications. However, the method was developed in specific geographical conditions, often making its universal applicability problematic. This study aims to determine appropriate values [...] Read more.
The SCS-CN method is a globally known procedure used primarily for direct-runoff estimates. It also is integrated in many modelling applications. However, the method was developed in specific geographical conditions, often making its universal applicability problematic. This study aims to determine appropriate values of initial abstraction coefficients λ and curve numbers (CNs), based on measured data in five experimental catchments in the Czech Republic, well representing the physiographic conditions in Central Europe, to improve direct-runoff estimates. Captured rainfall-runoff events were split into calibration and validation datasets. The calibration dataset was analysed by applying three approaches: (1) Modifying λ, both discrete and interpolated, using the tabulated CN values; (2) event analysis based on accumulated rainfall depth at the moment runoff starts to form; and (3) model fitting, an iterative procedure, to search for a pair of λ, S (CN, respectively). To assess individual rainfall characteristics’ possible influence, a principal component analysis and cluster analysis were conducted. The results indicate that the CN method in its traditional arrangement is not very applicable in the five experimental catchments and demands corresponding modifications to determine λ and CN (or S, respectively). Both λ and CN should be viewed as flexible, catchment-dependent (regional) parameters, rather than fixed values. The acquired findings show the need for a systematic yet site-specific revision of the traditional CN method, which may help to improve the accuracy of CN-based rainfall-runoff modelling. Full article
(This article belongs to the Special Issue Soil Conservation Service Curve Number (SCS-CN) Method Current Applications, Remaining Challenges, and Future Perspectives)
►▼ Show Figures

Figure 1

25 pages, 5498 KiB  
Article
Insights onto Hydrologic and Hydro-Chemical Processes of Riparian Groundwater Using Environmental Tracers in the Highly Disturbed Shaying River Basin, China
by Baoling Li, Xianfang Song, Lihu Yang, Dongxu Yao and Yingchun Xu
Water 2020, 12(7), 1939; https://doi.org/10.3390/w12071939 - 8 Jul 2020
Cited by 7 | Viewed by 2634
Abstract
Understanding the hydrologic and hydrochemistry processes in the riparian area is of great importance for managing and protecting riparian water resources. This paper took a highly disturbed and polluted Shaying River Basin (SRB) of China as the study area. In this research, environmental [...] Read more.
Understanding the hydrologic and hydrochemistry processes in the riparian area is of great importance for managing and protecting riparian water resources. This paper took a highly disturbed and polluted Shaying River Basin (SRB) of China as the study area. In this research, environmental tracers (hydrochemical and isotopic data of222Rn, δ18O, and δD) and corresponding models (two-component mixing model and 222Rn mass balance model) were employed to investigate the hydrologic and associated hydro-chemical process of riparian groundwater. The results indicated that rivers received groundwater discharge located at Xihua (J8), Zhoukou (Y1), Luohe (S2), and Shenqiu (SY2), and the mixing extent with groundwater was greater in wet seasons than in dry seasons. The 222Rn mass balance model showed that the flux of river water leakage was 3.27 × 10−4 m3/(s·m) at the front of Zhoukou sluice while groundwater discharge was 3.50 × 10−3 m3/(s·m) at the front of Shenqiu sluice during the sampling period. The cation exchange and the dissolution/precipitation of aquifer minerals (including calcite, dolomite, gypsum, and halite) were dominated by geochemical processes. The untreated sewage discharge and fertilizer usage were the main anthropogenic activities affecting the hydrochemistry process in surface water and riparian groundwater. Additionally, our results found that nitrate pollutants derived by riparian groundwater were potential threats to river quality at the lower reaches of Jialu River and Shenqiu county of Shaying River, where the nitrate inputs could be larger during the wet seasons because of higher groundwater discharge. Full article
(This article belongs to the Special Issue Applying Artificial and Environmental Tracing Techniques in Hydrogeology)
►▼ Show Figures

Figure 1

26 pages, 1197 KiB  
Article
Socio-Hydrology: A New Understanding to Unite or a New Science to Divide?
by Kaveh Madani and Majid Shafiee-Jood
Water 2020, 12(7), 1941; https://doi.org/10.3390/w12071941 - 8 Jul 2020
Cited by 45 | Viewed by 11505
Abstract
The socio-hydrology community has been very successful in promoting the need for taking the human factor into account in the mainstream hydrology literature since 2012. However, the interest in studying and modeling human-water systems is not new and pre-existed the post-2012 socio-hydrology. So, [...] Read more.
The socio-hydrology community has been very successful in promoting the need for taking the human factor into account in the mainstream hydrology literature since 2012. However, the interest in studying and modeling human-water systems is not new and pre-existed the post-2012 socio-hydrology. So, it is critical to ask what socio-hydrology has been able to offer that would have been unachievable using the existing methods, tools, and analysis frameworks. Thus far, the socio-hydrology studies show a strong overlap with what has already been in the literature, especially in the water resources systems and coupled human and natural systems (CHANS) areas. Nevertheless, the work in these areas has been generally dismissed by the socio-hydrology literature. This paper overviews some of the general concerns about originality, practicality, and contributions of socio-hydrology. It is argued that while in theory, a common sense about the need for considering humans as an integral component of water resources systems models can strengthen our coupled human-water systems research, the current approaches and trends in socio-hydrology can make this interest area less inclusive and interdisciplinary. Full article
(This article belongs to the Special Issue Application of the Systems Approach to the Management of Complex Water Systems)
►▼ Show Figures

Figure 1

34 pages, 24719 KiB  
Article
Multi-Collocation-Based Estimation of Wave Climate in a Non-Tidal Bay: The Case Study of Bagnoli-Coroglio Bay (Tyrrhenian Sea)
by Pasquale Contestabile, Fabio Conversano, Luca Centurioni, Umberto Mario Golia, Luigi Musco, Roberto Danovaro and Diego Vicinanza
Water 2020, 12(7), 1936; https://doi.org/10.3390/w12071936 - 7 Jul 2020
Cited by 8 | Viewed by 3128
Abstract
In this paper, the advantages of shaping a non-conventional triple collocation-based calibration of a wave propagation model is pointed out. Illustrated through a case study in the Bagnoli-Coroglio Bay (central Tyrrhenian Sea, Italy), a multi-comparison between numerical data and direct measurements have been [...] Read more.
In this paper, the advantages of shaping a non-conventional triple collocation-based calibration of a wave propagation model is pointed out. Illustrated through a case study in the Bagnoli-Coroglio Bay (central Tyrrhenian Sea, Italy), a multi-comparison between numerical data and direct measurements have been carried out. The nearshore wave propagation model output has been compared with measurements from an acoustic Doppler current profiler (ADCP) and an innovative low-cost drifter-derived GPS-based wave buoy located outside the bay. The triple collocation—buoy, ADCP and virtual numerical point—make possible an implicit validation between instrumentations and between instrumentation and numerical model. The procedure presented here advocates for an alternative “two-step” strategy. Indeed, the triple collocation technique has been used solely to provide a first “rough” calibration of one numerical domain in which the input open boundary has been placed, so that the main wave direction is orthogonally aligned. The need for a fast and sufficiently accurate estimation of wave model parameters (first step) and then an ensemble of five different offshore boundary orientations have been considered, referencing for a more detailed calibration to a short time series of a GPS-buoy installed in the study area (second step). Such a stage involves the introduction of an enhancement factor for the European Centre for Medium-Range Weather Forecasts (ECMWF) dataset, used as input for the model. Finally, validation of the final model’s predictions has been carried out by comparing ADCP measurements in the bay. Despite some limitations, the results reveal that the approach is promising and an excellent correlation can be found, especially in terms of significant wave height. Full article
(This article belongs to the Special Issue Coastal Vulnerability and Mitigation Strategies: From Monitoring to Applied Research )
►▼ Show Figures

Figure 1

20 pages, 7632 KiB  
Article
Comparative Analysis of Drought Indicated by the SPI and SPEI at Various Timescales in Inner Mongolia, China
by Zhifang Pei, Shibo Fang, Lei Wang and Wunian Yang
Water 2020, 12(7), 1925; https://doi.org/10.3390/w12071925 - 6 Jul 2020
Cited by 149 | Viewed by 8854
Abstract
The global climate is noticeably warming, and drought occurs frequently. Therefore, choosing a suitable index for drought monitoring is particularly important. The standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) are commonly used indicators in drought monitoring. The SPEI takes [...] Read more.
The global climate is noticeably warming, and drought occurs frequently. Therefore, choosing a suitable index for drought monitoring is particularly important. The standardized precipitation index (SPI) and the standardized precipitation evapotranspiration index (SPEI) are commonly used indicators in drought monitoring. The SPEI takes temperature into account, but the SPI does not. In the context of global warming, what are their differences and applicability in regional drought monitoring? In this study, after calculating the SPI and SPEI at 1-, 3-, 6-, and 12-month timescales at 102 meteorological stations in Inner Mongolia from 1981 to 2018, we compared and analyzed the performances of the SPI and SPEI in drought monitoring from temporal and spatial variations, and the consistency and applicability of the SPI and SPEI were also discussed. The results showed that (1) with increasing timescale, the temporal variations in the SPI and SPEI were increasingly consistent, but there were still slight differences in the fluctuation value and continuity; (2) due to the difference in time series, the drought characteristics identified by the SPI and SPEI were quite different in space at various timescales, and with the increase in timescale, the spatial distributions of the drought trends in Inner Mongolia were basically consistent, except in Alxa; (3) at the shortest timescale, the difference between the SPI and SPEI was the largest, and the drought reflected by the SPI and SPEI may be consistent at long timescales; and (4) compared with typical drought events and vegetation indexes, the SPEI may be more suitable than the SPI for drought monitoring in Inner Mongolia. It should be noted that the adaptability of the SPI and SPEI may be different in different periods and regions, which remains to be analyzed in the future. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

20 pages, 4294 KiB  
Article
Examining Water Area Changes Accompanying Dam Construction in the Madeira River in the Brazilian Amazon
by Dengqiu Li, Dengsheng Lu, Emilio Moran and Ramon Felipe Bicudo da Silva
Water 2020, 12(7), 1921; https://doi.org/10.3390/w12071921 - 6 Jul 2020
Cited by 13 | Viewed by 3328
Abstract
Two recently constructed run-of-the-river dams (Santo Antônio and Jirau), along the Madeira River in Brazil, have been controversial due to their large unquantified impacts on (1) land use and land cover (LULC) and (2) on the area that would be flooded. Based on [...] Read more.
Two recently constructed run-of-the-river dams (Santo Antônio and Jirau), along the Madeira River in Brazil, have been controversial due to their large unquantified impacts on (1) land use and land cover (LULC) and (2) on the area that would be flooded. Based on annual LULC data from 1985 to 2017, this study integrated intensity analysis and difference components methods to analyze the impacts of the two dams on the annual flooded area in upstream, midstream, and downstream regions of the Madeira River. The dam construction significantly influenced LULC change intensity in the upstream and midstream regions since 2011 and 2010, respectively. An increase of 18.5% of the newly flooded area (462.58 km2) in the post-dam construction period was observed. The water gross gain intensity was active during 2011–2017 and 2011–2014 in upstream and midstream, respectively. The dominant difference components of water change were exchanged in the pre-dam period and became quantity in the post-dam period for both upstream and midstream regions. Forest was the major land category replaced by water; however, the highest gain intensities occurred in other non-vegetated areas in upstream and midstream. This study provided a useful approach for characterizing impacts of dam construction on water area change. Full article
(This article belongs to the Special Issue Impacts of Climate Change and Anthropogenic Activities on the Spatio-Temporal Variability of River Flow)
►▼ Show Figures

Figure 1

16 pages, 11493 KiB  
Article
Estimation of Surface Water Runoff for a Semi-Arid Area Using RS and GIS-Based SCS-CN Method
by Hussein Al-Ghobari, Ahmed Dewidar and Abed Alataway
Water 2020, 12(7), 1924; https://doi.org/10.3390/w12071924 - 6 Jul 2020
Cited by 58 | Viewed by 7771
Abstract
The proper planning of storage structures, waterways, irrigation schemes, water harvesting, erosion control structures, and groundwater development strategies requires accurate estimation of surface runoff. However, hydrologists in Saudi Arabia face serious challenges, specifically due to the rare availability of surface runoff data. In [...] Read more.
The proper planning of storage structures, waterways, irrigation schemes, water harvesting, erosion control structures, and groundwater development strategies requires accurate estimation of surface runoff. However, hydrologists in Saudi Arabia face serious challenges, specifically due to the rare availability of surface runoff data. In this study, the soil conservation service-curve number (SCS-CN) method integrated with geographic information system (GIS) and remote sensing (RS) was utilized to estimate the surface runoff in Wadi-Uranah basin, in the western region of Saudi Arabia. Different thematic maps such as slope, hydrologic soil group (HSG), land use/land cover (LULC), and daily rainfall have been created in GIS environment and processed to generate the curve number (CN) and surface runoff maps. Based on the soil classification results, the study area was categorized into two HSGs (B and C). The dominant HSG was group C, representing about 98.8% of the total area. The LULC analysis showed four main land use types in the study region: urban, rocks, barren soil, and agricultural areas. Furthermore, the finding results showed that CN values for the normal conditions (CNII) ranged between 74 and 93 in agricultural and both urban and rock areas, respectively. The CNII values were further corrected using slope data to derive slope-adjusted CNII. Moreover, the rainfall-runoff results showed an increase in the daily runoff of the study region with a minimum of 15 mm to a maximum of 74 mm. Another interesting result was rainfall-runoff linear regression analysis that showed a good correlation of 0.98. Additionally, the peak runoff hydrograph flows for 10-, 50-, and 100-year return periods obtained from the SCS-based dimensionless unit hydrograph were 828, 1353, and 1603 m3/s, respectively. Therefore, this study highlights that the SCS-CN method integrated with RS and GIS deserves further attention for estimating runoff of ungauged basins for better basins management and conservation purposes. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

13 pages, 2191 KiB  
Article
Man-Induced Discrete Freshwater Discharge and Changes in Flow Structure and Bottom Turbulence in Altered Yeongsan Estuary, Korea
by KiRyong Kang and Guan-hong Lee
Water 2020, 12(7), 1919; https://doi.org/10.3390/w12071919 - 5 Jul 2020
Cited by 6 | Viewed by 2224
Abstract
Flow measurements were performed in the altered Yeongsan estuary, Korea, in August 2011, to investigate changes in flow structure in the water column and turbulence characteristics very close to the bed. Comparison between the bottom turbulent kinetic energy (TKE) and suspended sediment concentration [...] Read more.
Flow measurements were performed in the altered Yeongsan estuary, Korea, in August 2011, to investigate changes in flow structure in the water column and turbulence characteristics very close to the bed. Comparison between the bottom turbulent kinetic energy (TKE) and suspended sediment concentration (SSC) was conducted to examine how discrete freshwater discharge affects the bottom sediment concentration. The discrete freshwater discharge due to the gate opening of the Yeongsan estuarine dam induced a strong two-layer circulation: an offshore-flowing surface layer and a landward-flowing bottom layer. The fine flow structure from the bed to 0.35 m above the bottom (mab hereafter) exhibited an upside-down-bell-shaped profile for which current speed was nearly uniform above 0.1 mab, with the magnitude of the horizontal and vertical flow speeds reaching 0.1 and 0.01 m/s, respectively. The bottom turbulence responded to the freshwater discharge at the surface layer and the maximum magnitude of the Reynolds stress reached up to 2 × 10−4 m2/s2 during the discharged period, which coincided with increased SSC in the bottom boundary layer. These results indicate that the surface freshwater discharge due to opening of the estuarine dam gate increases the SSC by the discharge-induced intensification of the turbulent flow in the bottom boundary layer. Full article
(This article belongs to the Special Issue Turbulence and Flow–Sediment Interactions in Open-Channel Flows)
►▼ Show Figures

Figure 1

17 pages, 9703 KiB  
Article
Experimental Assessment of the Flow Resistance of Coastal Wooden Fences
by Hoang Tung Dao, Bas Hofland, Marcel J. F. Stive and Tri Mai
Water 2020, 12(7), 1910; https://doi.org/10.3390/w12071910 - 4 Jul 2020
Cited by 12 | Viewed by 4423
Abstract
Wooden fences are applied as a nature-based solution to support mangrove restoration along mangrove coasts in general and the Mekong Delta coast in particular. The simple structure uses vertical bamboo poles as a frame to store horizontal bamboo and tree branches (brushwood). Fence [...] Read more.
Wooden fences are applied as a nature-based solution to support mangrove restoration along mangrove coasts in general and the Mekong Delta coast in particular. The simple structure uses vertical bamboo poles as a frame to store horizontal bamboo and tree branches (brushwood). Fence resistance is quantitatively determined by the drag coefficient exerted by the fence material on the flow; however, the behaviour of drag is predictable only when the arrangement of the cylinders is homogeneous. Therefore, for more arbitrary arrangements, the Darcy–Forchheimer equations need to be considered. In this study, the law of fluid flow was applied by forcing a constant flow of water through the fence material and measuring the loss of hydraulic pressure over a fence thickness. Fences, mainly using bamboo sticks, were installed with model-scale and full-scale diameters applying two main arrangements, inhomogeneous and staggered. Our empirical findings led to several conclusions. The bulk drag coefficient ( C D ¯ ) is influenced by the flow regime represented by Reynolds number. The drag coefficient decreases with the increase of the porosity, which strongly depends on fence arrangements. Finally, the Forchheimer coefficients can be linked to the drag coefficient through a related porosity parameter at high turbulent conditions. The staggered arrangement is well-predicted by the Ergun-relations for the Darcy–Forchheimer coefficients when an inhomogeneous arrangement with equal porosity and diameter leads to a large drag and flow resistance. Full article
(This article belongs to the Special Issue Nature-Based Solutions for Coastal Engineering and Management)
►▼ Show Figures

Figure 1

23 pages, 70913 KiB  
Article
Beyond Human Interventions on Complex Bays: Effects on Water and Wave Dynamics (Study Case Cádiz Bay, Spain)
by Carmen Zarzuelo, Alejandro López-Ruiz and Miguel Ortega-Sánchez
Water 2020, 12(7), 1907; https://doi.org/10.3390/w12071907 - 3 Jul 2020
Cited by 8 | Viewed by 2435
Abstract
Bays are coastal environments with significant socio-economic importance, which has led to the development of human interventions in their interior that can have an important impact on the water and wave dynamics, which in turn modify their morphodynamics and water renewal capacity. In [...] Read more.
Bays are coastal environments with significant socio-economic importance, which has led to the development of human interventions in their interior that can have an important impact on the water and wave dynamics, which in turn modify their morphodynamics and water renewal capacity. In order to deepen our understanding of these impacts, numerical modeling was used in a bay in southern Spain to analyze the effect of inner harbor expansion and channel deepening, including the baroclinic and wave propagation effects, as well as variations in salinity and temperature. The results show that the deepening of the channel decreases the amplitude and speed of the tidal wave as it propagates through the bay, reducing the effects of friction and increasing the flushing time. The system evolves from convergent to a damping system that can potentially reduce the effects produced by projected sea level rise. In addition, the seasonal variability of salinity and temperature is reduced, increasing the bed shear stresses and resulting in increased turbidity that can affect the biogeochemistry of the bay. Finally, wave heights decrease along the main waterway, although the yearly-average wave energy flux is only slightly modified on the interior beaches of the bay. However, significant variations are observed during storms, which could affect the morphodynamics of these beaches. Full article
(This article belongs to the Section Oceans and Coastal Zones)
►▼ Show Figures

Figure 1

11 pages, 439 KiB  
Article
Water–Energy–Food Nexus Framework for Promoting Regional Integration in Central Asia
by Olimjon Saidmamatov, Inna Rudenko, Stephan Pfister and Jacek Koziel
Water 2020, 12(7), 1896; https://doi.org/10.3390/w12071896 - 3 Jul 2020
Cited by 32 | Viewed by 6826
Abstract
This paper focuses on regional integration through the lenses of the Water–Food–Energy (WEF) nexus, a concept putting strong emphasis on cross-sectoral and multi-level interactions as well as on resource interdependencies. There is an extensive amount of published research focusing on the Aral Sea [...] Read more.
This paper focuses on regional integration through the lenses of the Water–Food–Energy (WEF) nexus, a concept putting strong emphasis on cross-sectoral and multi-level interactions as well as on resource interdependencies. There is an extensive amount of published research focusing on the Aral Sea basin. In this paper, the authors build upon these different contributions and provide a meta-analysis of the literature of WEF nexus opportunities in Central Asia (CA) countries. This paper contributes to ongoing discussions regarding how the WEF Nexus can represent an opportunity for reinforced collaboration regarding resources management. To do so, focusing on existing literature, this paper first (1) explores how the nexus can be a relevant instrument for regional integration. Second (2), it provides an overview of water, food, energy conditions and challenges in the Aral Sea basin in particular. Third (3), synthesizing existing research, the authors identify critical variables to be considered as hurdles or leverage points for WEF nexus implementation in the Aral Sea basin. Finally (4), we go back to our initial set of questions and identify some possible avenues for future research. Full article
(This article belongs to the Special Issue Management of Water-Energy-Food Security Nexus)
►▼ Show Figures

Figure 1

18 pages, 2107 KiB  
Article
Ecological Environment Evaluation of Forest Ecosystem Nature Reserves Using an Unweighted Cloud Model
by Mengshi Xiang, Xiaonan Lin, Xiyan Yang and Shanghong Zhang
Water 2020, 12(7), 1905; https://doi.org/10.3390/w12071905 - 3 Jul 2020
Cited by 7 | Viewed by 2451
Abstract
The ecological environment is the foundation of human survival and development, and forest ecosystem nature reserves play an important role in the protection of the ecological environment. The evaluation of forest ecosystem nature reserves facilitates the formulation of relevant management policies. At present, [...] Read more.
The ecological environment is the foundation of human survival and development, and forest ecosystem nature reserves play an important role in the protection of the ecological environment. The evaluation of forest ecosystem nature reserves facilitates the formulation of relevant management policies. At present, the evaluation of the ecological environment of forest ecosystem nature reserves is mainly based on detailed evaluation of some elements of the ecological environment, rather than on a comprehensive quantitative evaluation that reflects the ecological environment in many aspects. To address this shortcoming, the quantitative evaluation indicator system of comprehensive ecological environment for forest ecosystem nature reserves was established based on the water, air, soil, and biological environments, according to the consensus on ecological environment in the past research and characteristics of the research area. The weight is still a necessary and important link in the evaluation of forest ecosystem nature reserves, but the accuracy of the weight results is difficult to get a scientific judgment. To prevent the evaluation results being influenced by weighting uncertainty, an unweighted cloud model was constructed to provide an evaluation mechanism without weight. The ecological environment evaluation was then carried out using the unweighted cloud model, taking Songshan Nature Reserve as a research area. The results show that the grades of the ecological environment of Songshan Nature Reserve are 21% excellent, 67% good, and 12% qualified, and that the state of the ecological environment is stable and performing well. The evaluation results for the grades of the environmental dimension layers are water environment > soil environment > biological environment > air environment. The study’s research results can provide theoretical support for the evaluation of forest ecosystem nature reserves, and for evaluation work in general when weights are difficult to determine or uncertain. Full article
►▼ Show Figures

Figure 1

20 pages, 6533 KiB  
Article
Hydrologic Assessment of TRMM and GPM-Based Precipitation Products in Transboundary River Catchment (Chenab River, Pakistan)
by Ehtesham Ahmed, Firas Al Janabi, Jin Zhang, Wenyu Yang, Naeem Saddique and Peter Krebs
Water 2020, 12(7), 1902; https://doi.org/10.3390/w12071902 - 3 Jul 2020
Cited by 23 | Viewed by 5614
Abstract
Water resources planning and management depend on the quality of climatic data, particularly rainfall data, for reliable hydrological modeling. This can be very problematic in transboundary rivers with limited disclosing of data among the riparian countries. Satellite precipitation products are recognized as a [...] Read more.
Water resources planning and management depend on the quality of climatic data, particularly rainfall data, for reliable hydrological modeling. This can be very problematic in transboundary rivers with limited disclosing of data among the riparian countries. Satellite precipitation products are recognized as a promising source to substitute the ground-based observations in these conditions. This research aims to assess the feasibility of using a satellite-based precipitation product for better hydrological modeling in an ungauged and riparian river in Pakistan, i.e., the Chenab River. A semidistributed hydrological model of The soil and water assessment tool (SWAT) was set up and two renowned satellite precipitation products, i.e., global precipitation mission (GPM) IMERG-F v6 and tropical rainfall measuring mission (TRMM) 3B42 v7, were selected to assess the runoff pattern in Chenab River. The calibration was done from 2001–2006 with two years of a warmup period. The validation (2007–2010) results exhibit higher correlation between observed and simulated discharges at monthly timescale simulations, IMERG-F (R2 = 0.89, NSE = 0.82), 3B42 (R2 = 0.85, NSE = 0.72), rather than daily timescale simulations, IMERG-F (R2 = 0.66, NSE = 0.61), 3B42 (R2 = 0.64, NSE = 0.54). Moreover, the comparison between IMERG-F and 3B42, shows that IMERG-F is superior to 3B42 by indicating higher R2, NSE and lower percent bias (PBIAS) at both monthly and daily timescale. The results are strengthened by Taylor diagram statistics, which represent a higher correlation (R) and less RMS error between observed and simulated values for IMERG-F. IMERG-F has great potential utility in the Chenab River catchment as it outperformed the 3B42 precipitation in this study. However, its poor skill of capturing peaks at daily timescale remains, leaving a room for IMERG-F to improve its algorithm in the upcoming release. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

19 pages, 7964 KiB  
Article
Identification of the Optimum Rain Gauge Network Density for Hydrological Modelling Based on Radar Rainfall Analysis
by Yeboah Gyasi-Agyei
Water 2020, 12(7), 1906; https://doi.org/10.3390/w12071906 - 3 Jul 2020
Cited by 18 | Viewed by 4142
Abstract
Rain gauges continue to be sources of rainfall data despite progress made in precipitation measurements using radar and satellite technology. There has been some work done on assessing the optimum rain gauge network density required for hydrological modelling, but without consensus. This paper [...] Read more.
Rain gauges continue to be sources of rainfall data despite progress made in precipitation measurements using radar and satellite technology. There has been some work done on assessing the optimum rain gauge network density required for hydrological modelling, but without consensus. This paper contributes to the identification of the optimum rain gauge network density, using scaling laws and bias-corrected 1 km × 1 km grid radar rainfall records, covering an area of 28,371 km2 that hosts 315 rain gauges in south-east Queensland, Australia. Varying numbers of radar pixels (rain gauges) were repeatedly sampled using a unique stratified sampling technique. For each set of rainfall sampled data, a two-dimensional correlogram was developed from the normal scores obtained through quantile-quantile transformation for ordinary kriging which is a stochastic interpolation. Leave-one-out cross validation was carried out, and the simulated quantiles were evaluated using the performance statistics of root-mean-square-error and mean-absolute-bias, as well as their rates of change. A break in the scaling of the plots of these performance statistics against the number of rain gauges was used to infer the optimum rain gauge network density. The optimum rain gauge network density varied from 14 km2/gauge to 38 km2/gauge, with an average of 25 km2/gauge. Full article
(This article belongs to the Special Issue Stochastic Modelling of Hydrometeorological Processes for Engineering Applications)
►▼ Show Figures

Figure 1

27 pages, 4594 KiB  
Article
Comparison of the MUSLE Model and Two Years of Solid Transport Measurement, in the Bouregreg Basin, and Impact on the Sedimentation in the Sidi Mohamed Ben Abdellah Reservoir, Morocco
by Mohamed Abdellah Ezzaouini, Gil Mahé, Ilias Kacimi and Abdelaziz Zerouali
Water 2020, 12(7), 1882; https://doi.org/10.3390/w12071882 - 1 Jul 2020
Cited by 32 | Viewed by 4016
Abstract
The evaluation and quantification of solids transport in Morocco often uses the Universal Soil Loss Model (USLE) and the revised version RUSLE, which presents a calibration difficulty. In this study, we apply the MUSLE model to predict solid transport, for the first time [...] Read more.
The evaluation and quantification of solids transport in Morocco often uses the Universal Soil Loss Model (USLE) and the revised version RUSLE, which presents a calibration difficulty. In this study, we apply the MUSLE model to predict solid transport, for the first time on a large river basin in the Kingdom, calibrated by two years of solid transport measurements on four main gauging stations at the entrance of the Sidi Mohamed Ben Abdellah dam. The application of the MUSLE on the basin demonstrated relatively small differences between the measured values and those expected for the calibrated version, these differences are, for the non-calibrated version, +5% and +102% for the years 2016/2017 and 2017/2018 respectively, and between −33% and +34% for the calibrated version. Besides, the measured and modeled volumes that do not exceed 1.78 × 106 m3/year remain well below the dam’s siltation rate of 9.49 × 106 m3/year, which means that only 18% of the dam’s sediment comes from upstream. This seems very low because it is calculated from only two years. The main hypothesis that we can formulate is that the sediments of the dam most probably comes from the erosion of its banks. Full article
(This article belongs to the Special Issue Multiscale Impacts of Anthropogenic and Climate Changes on Tropical and Mediterranean Hydrology)
►▼ Show Figures

Figure 1

17 pages, 1732 KiB  
Article
Urban Water Demand Prediction for a City That Suffers from Climate Change and Population Growth: Gauteng Province Case Study
by Salah L. Zubaidi, Sandra Ortega-Martorell, Hussein Al-Bugharbee, Ivan Olier, Khalid S. Hashim, Sadik Kamel Gharghan, Patryk Kot and Rafid Al-Khaddar
Water 2020, 12(7), 1885; https://doi.org/10.3390/w12071885 - 1 Jul 2020
Cited by 130 | Viewed by 11817
Abstract
The proper management of a municipal water system is essential to sustain cities and support the water security of societies. Urban water estimating has always been a challenging task for managers of water utilities and policymakers. This paper applies a novel methodology that [...] Read more.
The proper management of a municipal water system is essential to sustain cities and support the water security of societies. Urban water estimating has always been a challenging task for managers of water utilities and policymakers. This paper applies a novel methodology that includes data pre-processing and an Artificial Neural Network (ANN) optimized with the Backtracking Search Algorithm (BSA-ANN) to estimate monthly water demand in relation to previous water consumption. Historical data of monthly water consumption in the Gauteng Province, South Africa, for the period 2007–2016, were selected for the creation and evaluation of the methodology. Data pre-processing techniques played a crucial role in the enhancing of the quality of the data before creating the prediction model. The BSA-ANN model yielded the best result with a root mean square error and a coefficient of efficiency of 0.0099 mega liters and 0.979, respectively. Moreover, it proved more efficient and reliable than the Crow Search Algorithm (CSA-ANN), based on the scale of error. Overall, this paper presents a new application for the hybrid model BSA-ANN that can be successfully used to predict water demand with high accuracy, in a city that heavily suffers from the impact of climate change and population growth. Full article
(This article belongs to the Special Issue Advanced Applications of Electrocoagulation in Water and Wastewater)
►▼ Show Figures

Figure 1

28 pages, 4267 KiB  
Article
Application of GWO-ELM Model to Prediction of Caojiatuo Landslide Displacement in the Three Gorge Reservoir Area
by Liguo Zhang, Xinquan Chen, Yonggang Zhang, Fuwei Wu, Fei Chen, Weiting Wang and Fei Guo
Water 2020, 12(7), 1860; https://doi.org/10.3390/w12071860 - 29 Jun 2020
Cited by 37 | Viewed by 3628
Abstract
In order to establish an effective early warning system for landslide disasters, accurate landslide displacement prediction is the core. In this paper, a typical step-wise-characterized landslide (Caojiatuo landslide) in the Three Gorges Reservoir (TGR) area is selected, and a displacement prediction model of [...] Read more.
In order to establish an effective early warning system for landslide disasters, accurate landslide displacement prediction is the core. In this paper, a typical step-wise-characterized landslide (Caojiatuo landslide) in the Three Gorges Reservoir (TGR) area is selected, and a displacement prediction model of Extreme Learning Machine with Gray Wolf Optimization (GWO-ELM model) is proposed. By analyzing the monitoring data of landslide displacement, the time series of landslide displacement is decomposed into trend displacement and periodic displacement by using the moving average method. First, the trend displacement is fitted by the cubic polynomial with a robust weighted least square method. Then, combining with the internal evolution rule and the external influencing factors, it is concluded that the main external trigger factors of the periodic displacement are the changes of precipitation and water level in the reservoir area. Gray relational degree (GRG) analysis method is used to screen out the main influencing factors of landslide periodic displacement. With these factors as input items, the GWO-ELM model is used to predict the periodic displacement of the landslide. The outcomes are compared with the nonoptimized ELM model. The results show that, combined with the advantages of the GWO algorithm, such as few adjusting parameters and strong global search ability, the GWO-ELM model can effectively learn the change characteristics of data and has a better and relatively stable prediction accuracy. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

21 pages, 9710 KiB  
Article
Experimental Application of Sediment Flow Connectivity Index (SCI) in Flood Monitoring
by Marina Zingaro, Alberto Refice, Annarita D’Addabbo, Renaud Hostache, Marco Chini and Domenico Capolongo
Water 2020, 12(7), 1857; https://doi.org/10.3390/w12071857 - 28 Jun 2020
Cited by 10 | Viewed by 3762
Abstract
Sediment connectivity is considered a powerful geomorphic indicator for defining the most sensitive areas to geomorphological modifications in a fluvial catchment (hotspots). This encourages the development of methods and models for its assessment, to investigate the interrelation of the various phenomena that occur [...] Read more.
Sediment connectivity is considered a powerful geomorphic indicator for defining the most sensitive areas to geomorphological modifications in a fluvial catchment (hotspots). This encourages the development of methods and models for its assessment, to investigate the interrelation of the various phenomena that occur in a river basin (landslides, floods, etc.). This work explores the potential connection of the processes in flood dynamics, by focusing on induced flood hazard, in order to evaluate the applicability of sediment connectivity to flood monitoring. By applying the recently developed sediment flow connectivity index (SCI) computation method to the Severn River basin, in UK, recurrently affected by floods, we investigate the agreement between the hotspot areas (described by the index) and the areas recurrently flooded (as mapped by aerial photography, satellite imagery and hydrodynamic modelling). Qualitative and quantitative approaches are used for the analysis of past (March 2007 and January 2010) as well as predicted (with return periods of 200 and 500 years) flood events. The results show a good correspondence of areas of high sediment connectivity with flood occurrence. Moreover, the detection performance of the SCI is slightly better than that of a simple flow accumulation map, confirming the importance of the initial mapping of sediment availability and mobility. This experiment extends the direct applicability of the SCI from fluvial analysis to flood monitoring, thus opening interesting future scenarios. Full article
(This article belongs to the Special Issue Fluvial Geomorphology and River Management)
►▼ Show Figures

Graphical abstract

16 pages, 2608 KiB  
Article
Mass Balance of the Greenland Ice Sheet from GRACE and Surface Mass Balance Modelling
by Fang Zou, Robert Tenzer, Hok Sum Fok and Janet E. Nichol
Water 2020, 12(7), 1847; https://doi.org/10.3390/w12071847 - 28 Jun 2020
Cited by 10 | Viewed by 4011
Abstract
The Greenland Ice Sheet (GrIS) is losing mass at a rate that represents a major contribution to global sea-level rise in recent decades. In this study, we use the Gravity Recovery and Climate Experiment (GRACE) data to retrieve the time series variations of [...] Read more.
The Greenland Ice Sheet (GrIS) is losing mass at a rate that represents a major contribution to global sea-level rise in recent decades. In this study, we use the Gravity Recovery and Climate Experiment (GRACE) data to retrieve the time series variations of the GrIS from April 2002 to June 2017. We also estimate the mass balance from the RACMO2.3 and ice discharge data in order to obtain a comparative analysis and cross-validation. A detailed analysis of long-term trend and seasonal and inter-annual changes in the GrIS is implemented by GRACE and surface mass balance (SMB) modeling. The results indicate a decrease of −267.77 ± 8.68 Gt/yr of the GrIS over the 16-year period. There is a rapid decline from 2002 to 2008, which accelerated from 2009 to 2012 before declining relatively slowly from 2013 to 2017. The mass change inland is significantly smaller than that detected along coastal regions, especially in the southeastern, southwestern, and northwestern regions. The mass balance estimates from GRACE and SMB minus ice discharge (SMB-D) are very consistent. The ice discharge manifests itself mostly as a long-term trend, whereas seasonal mass variations are largely attributed to surface mass processes. The GrIS mass changes are mostly attributed to mass loss during summer. Summer mass changes are highly correlated with climate changes. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

14 pages, 1674 KiB  
Review
Protection Motivation Theory: A Proposed Theoretical Extension and Moving beyond Rationality—The Case of Flooding
by Matthew Oakley, Sam Mohun Himmelweit, Paul Leinster and Mónica Rivas Casado
Water 2020, 12(7), 1848; https://doi.org/10.3390/w12071848 - 28 Jun 2020
Cited by 40 | Viewed by 11805
Abstract
Despite the significant financial and non-financial costs of household flooding, and the availability of products that can reduce the risk or impact of flooding, relatively few consumers choose to adopt these products. To help explain this, we combine the existing theoretical literature with [...] Read more.
Despite the significant financial and non-financial costs of household flooding, and the availability of products that can reduce the risk or impact of flooding, relatively few consumers choose to adopt these products. To help explain this, we combine the existing theoretical literature with evidence from 20 one-to-one discussions and three workshops with key stakeholders, as well as five round tables, to draw practical evidence of actual responses to flood risk. This analysis leads us to propose an extension to Protection Motivation Theory (PMT), which more accurately captures the decision-making process of consumers by highlighting the role of ‘ownership appraisal’. We then assess the extent to which behavioral biases impact on this revised framework. By highlighting the interaction with an augmented model of PMT and behavioral biases, the paper sheds light on potential reasons behind the fact that consumers are unlikely to adopt property-level flood resilience measures and identifies strategies to increase flood protection. The Augmented PMT suggests that policymakers might focus on increasing the Ownership Appraisal element, both directly and by targeting the creation of more supportive social norms. The work presented here opens up a wide range of areas for future research in the field. Full article
(This article belongs to the Special Issue Environmental Risk Management)
►▼ Show Figures

Graphical abstract

10 pages, 1784 KiB  
Article
Image Segmentation Methods for Flood Monitoring System
by Nur Atirah Muhadi, Ahmad Fikri Abdullah, Siti Khairunniza Bejo, Muhammad Razif Mahadi and Ana Mijic
Water 2020, 12(6), 1825; https://doi.org/10.3390/w12061825 - 26 Jun 2020
Cited by 30 | Viewed by 6361
Abstract
Flood disasters are considered annual disasters in Malaysia due to their consistent occurrence. They are among the most dangerous disasters in the country. Lack of data during flood events is the main constraint to improving flood monitoring systems. With the rapid development of [...] Read more.
Flood disasters are considered annual disasters in Malaysia due to their consistent occurrence. They are among the most dangerous disasters in the country. Lack of data during flood events is the main constraint to improving flood monitoring systems. With the rapid development of information technology, flood monitoring systems using a computer vision approach have gained attention over the last decade. Computer vision requires an image segmentation technique to understand the content of the image and to facilitate analysis. Various segmentation algorithms have been developed to improve results. This paper presents a comparative study of image segmentation techniques used in extracting water information from digital images. The segmentation methods were evaluated visually and statistically. To evaluate the segmentation methods statistically, the dice similarity coefficient and the Jaccard index were calculated to measure the similarity between the segmentation results and the ground truth images. Based on the experimental results, the hybrid technique obtained the highest values among the three methods, yielding an average of 97.70% for the dice score and 95.51% for the Jaccard index. Therefore, we concluded that the hybrid technique is a promising segmentation method compared to the others in extracting water features from digital images. Full article
(This article belongs to the Special Issue Flood Inundation Modelling and Assessment of Current and Future Flood Risk)
►▼ Show Figures

Figure 1

24 pages, 2261 KiB  
Article
Conserving Mekong Megafishes: Current Status and Critical Threats in Cambodia
by Teresa Campbell, Kakada Pin, Peng Bun Ngor and Zeb Hogan
Water 2020, 12(6), 1820; https://doi.org/10.3390/w12061820 - 25 Jun 2020
Cited by 26 | Viewed by 7033
Abstract
Megafishes are important to people and ecosystems worldwide. These fishes attain a maximum body weight of ≥30 kg. Global population declines highlight the need for more information about megafishes’ conservation status to inform management and conservation. The northern Cambodian Mekong River and its [...] Read more.
Megafishes are important to people and ecosystems worldwide. These fishes attain a maximum body weight of ≥30 kg. Global population declines highlight the need for more information about megafishes’ conservation status to inform management and conservation. The northern Cambodian Mekong River and its major tributaries are considered one of the last refugia for Mekong megafishes. We collected data on population abundance and body size trends for eight megafishes in this region to better understand their conservation statuses. Data were collected in June 2018 using a local ecological knowledge survey of 96 fishers in 12 villages. Fishers reported that, over 20 years, most megafishes changed from common to uncommon, rare, or locally extirpated. The most common and rarest species had mean last capture dates of 4.5 and 95 months before the survey, respectively. All species had declined greatly in body size. Maximum body weights reported by fishers ranged from 11–88% of their recorded maxima. Fishers identified 10 threats to megafishes, seven of which were types of illegal fishing. Electrofishing was the most prevalent. Results confirm that Mekong megafishes are severely endangered. Species Conservation Strategies should be developed and must address pervasive illegal fishing activities, alongside habitat degradation and blocked migrations, to recover declining populations. Full article
(This article belongs to the Special Issue Channels for Change: Integrating Multiple Disciplines for New Frontiers in Managing the Mekong River Basin)
►▼ Show Figures

Figure 1

18 pages, 6145 KiB  
Article
Prediction of Chlorophyll-a Concentrations in the Nakdong River Using Machine Learning Methods
by Yuna Shin, Taekgeun Kim, Seoksu Hong, Seulbi Lee, EunJi Lee, SeungWoo Hong, ChangSik Lee, TaeYeon Kim, Man Sik Park, Jungsu Park and Tae-Young Heo
Water 2020, 12(6), 1822; https://doi.org/10.3390/w12061822 - 25 Jun 2020
Cited by 69 | Viewed by 6040
Abstract
Many studies have attempted to predict chlorophyll-a concentrations using multiple regression models and validating them with a hold-out technique. In this study commonly used machine learning models, such as Support Vector Regression, Bagging, Random Forest, Extreme Gradient Boosting (XGBoost), Recurrent Neural Network [...] Read more.
Many studies have attempted to predict chlorophyll-a concentrations using multiple regression models and validating them with a hold-out technique. In this study commonly used machine learning models, such as Support Vector Regression, Bagging, Random Forest, Extreme Gradient Boosting (XGBoost), Recurrent Neural Network (RNN), and Long–Short-Term Memory (LSTM), are used to build a new model to predict chlorophyll-a concentrations in the Nakdong River, Korea. We employed 1–step ahead recursive prediction to reflect the characteristics of the time series data. In order to increase the prediction accuracy, the model construction was based on forward variable selection. The fitted models were validated by means of cumulative learning and rolling window learning, as opposed to the hold–out technique. The best results were obtained when the chlorophyll-a concentration was predicted by combining the RNN model with the rolling window learning method. The results suggest that the selection of explanatory variables and 1–step ahead recursive prediction in the machine learning model are important processes for improving its prediction performance. Full article
►▼ Show Figures

Figure 1

25 pages, 2371 KiB  
Article
Watershed Hydrological Response to Combined Land Use/Land Cover and Climate Change in Highland Ethiopia: Finchaa Catchment
by Wakjira Takala Dibaba, Tamene Adugna Demissie and Konrad Miegel
Water 2020, 12(6), 1801; https://doi.org/10.3390/w12061801 - 24 Jun 2020
Cited by 106 | Viewed by 6715
Abstract
Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to [...] Read more.
Land use/land cover (LULC) and climate change affect the availability of water resources by altering the magnitude of surface runoff, aquifer recharge, and river flows. The evaluation helps to identify the level of water resources exposure to the changes that could help to plan for potential adaptive capacity. In this research, Cellular Automata (CA)-Markov in IDRISI software was used to predict the future LULC scenarios and the ensemble mean of four regional climate models (RCMs) in the coordinated regional climate downscaling experiment (CORDEX)-Africa was used for the future climate scenarios. Distribution mapping was used to bias correct the RCMs outputs, with respect to the observed precipitation and temperature. Then, the Soil and Water Assessment Tool (SWAT) model was used to evaluate the watershed hydrological responses of the catchment under separate, and combined, LULC and climate change. The result shows the ensemble mean of the four RCMs reported precipitation decline and increase in future temperature under both representative concentration pathways (RCP4.5 and RCP8.5). The increases in both maximum and minimum temperatures are higher for higher emission scenarios showing that RCP8.5 projection is warmer than RCP4.5. The changes in LULC brings an increase in surface runoff and water yield and a decline in groundwater, while the projected climate change shows a decrease in surface runoff, groundwater and water yield. The combined study of LULC and climate change shows that the effect of the combined scenario is similar to that of climate change only scenario. The overall decline of annual flow is due to the decline in the seasonal flows under combined scenarios. This could bring the reduced availability of water for crop production, which will be a chronic issue of subsistence agriculture. The possibility of surface water and groundwater reduction could also affect the availability of water resources in the catchment and further aggravate water stress in the downstream. The highly rising demands of water, owing to socio-economic progress, population growth and high demand for irrigation water downstream, in addition to the variability temperature and evaporation demands, amplify prolonged water scarcity. Consequently, strong land-use planning and climate-resilient water management policies will be indispensable to manage the risks. Full article
(This article belongs to the Special Issue Hydrological Impacts of Climate Change and Land Use)
►▼ Show Figures

Figure 1

26 pages, 5171 KiB  
Article
Spatial Dependence Modeling of Flood Risk Using Max-Stable Processes: The Example of Austria
by Hansjörg Albrecher, Dominik Kortschak and Franz Prettenthaler
Water 2020, 12(6), 1805; https://doi.org/10.3390/w12061805 - 24 Jun 2020
Cited by 5 | Viewed by 2684
Abstract
We propose a new approach to model the dependence structure for aggregating the risk of flood damages from a local level to larger areas, which is based on the structure of the river network of a country and can be calibrated with publicly [...] Read more.
We propose a new approach to model the dependence structure for aggregating the risk of flood damages from a local level to larger areas, which is based on the structure of the river network of a country and can be calibrated with publicly available data of river discharges. Building upon a suitable adaptation of max-stable processes for a flood-relevant geometry as recently introduced in the literature, this enables the assessment of flood risk without the need for a hydrological model, and can easily be adapted for different countries. We illustrate its use for the particular case of Austria. We first develop marginal flood models for individual municipalities by intertwining available HORA risk maps with the actual location of buildings. As a second alternative for the marginal modeling, we advocate an approach based on suitably normalized historical damage data of municipalities together with techniques from extreme value statistics. We implement and compare the two alternatives and apply the calibrated dependence structure to each of them, leading to estimates for average flood damage as well as its extreme quantiles on the municipality, state, and country level. This also allows us to quantify the diversification potential for flood risk on each of these levels, a topic of considerable importance in view of the natural and strong spatial dependence of this particular natural peril. Full article
(This article belongs to the Special Issue Recent Advances and New Directions in Flood Forecasting, Modeling, and Mapping)
►▼ Show Figures

Figure 1

22 pages, 8274 KiB  
Article
Applied Strategy to Characterize the Energy Improvement Using PATs in a Water Supply System
by Luis E. Camilo Rosado, P. Amparo López-Jiménez, Francisco-Javier Sánchez-Romero, Pilar Conejos Fuertes and Modesto Pérez-Sánchez
Water 2020, 12(6), 1818; https://doi.org/10.3390/w12061818 - 24 Jun 2020
Cited by 15 | Viewed by 3005
Abstract
Sustainable development has been an idea raised in recent years. The results are related to the improvement and the use of new technologies to maximize efficiency in water management. However, energy consumption has been increasing as a consequence of new management and uses [...] Read more.
Sustainable development has been an idea raised in recent years. The results are related to the improvement and the use of new technologies to maximize efficiency in water management. However, energy consumption has been increasing as a consequence of new management and uses of water. Especially in pressurized water distribution systems, the use of pressure reduction valves (PRVs) increases the water usage efficiency but it decreases the energy consumption efficiency, since the valves dissipate energy that could be recovered. This research presents a proposal of a recovery system based on the installation of pumps used as turbines (PATs). These machines are located in different points of the high-pressure water distribution system in the Valencia Metropolitan System (Spain). An annual estimate of the theoretical recoverable energy as well as the “ideal” pump for each point were proposed. The theoretical recovered energy value was 847,301 kWh/year for a specific analyzed point. Besides, the characteristic curves of the PATs from a selected point were determined, estimating an improvement in the sustainable indexes. The calculus of these green parameters showed that the implementation of this solution caused a reduction in consumed energy of 1.50 kWh/m3. Full article
(This article belongs to the Special Issue Hydraulic Dynamic Calculation and Simulation)
►▼ Show Figures

Figure 1

13 pages, 2812 KiB  
Article
Isotopic ‘Altitude’ and ‘Continental’ Effects in Modern Precipitation across the Adriatic–Pannonian Region
by Zoltán Kern, István Gábor Hatvani, György Czuppon, István Fórizs, Dániel Erdélyi, Tjaša Kanduč, László Palcsu and Polona Vreča
Water 2020, 12(6), 1797; https://doi.org/10.3390/w12061797 - 24 Jun 2020
Cited by 42 | Viewed by 4844
Abstract
It is generally observed that precipitation is gradually depleted in 18O and 2H isotopes as elevation increases (‘altitude’ effect) or when moving inland from seacoasts (‘continental’ effect); the regionally accurate estimation of these large-scale effects is important in isotope hydrological or [...] Read more.
It is generally observed that precipitation is gradually depleted in 18O and 2H isotopes as elevation increases (‘altitude’ effect) or when moving inland from seacoasts (‘continental’ effect); the regionally accurate estimation of these large-scale effects is important in isotope hydrological or paleoclimatological applications. Nevertheless, seasonal and spatial differences should be considered. Stable isotope composition of monthly precipitation fallen between January 2016 and December 2018 was studied for selected stations situated along an elevation transect and a continental transect in order to assess the isotopic ‘altitude’ and ‘continental’ effects in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics argue that the main driver of the apparent vertical depletion of precipitation in heavy stable isotopes is different in summer (raindrop evaporation) and winter (condensation), although, there is no significant difference in the resulting ‘altitude’ effect. Specifically, an ‘altitude’ effect of −1.2‰/km for δ18O and −7.9‰/km for δ2H can be used in modern precipitation across the Adriatic–Pannonian region. Isotopic characteristics of monthly precipitation showed seasonally different patterns and suggest different isotope hydrometeorological regimes along the continental transect. While no significant decrease was found in δ18O data moving inland from the Adriatic from May to August of the year, a clear decreasing trend was found in precipitation fallen during the colder season of the year (October to March) up to a break at ~400 km inland from the Adriatic coast. The estimated mean isotopic ‘continental’ effect for the colder season precipitation is −2.4‰/100 km in δ18O and −20‰/100 km in δ2H. A prevailing influence of the Mediterranean moisture in the colder season is detected up to this breakpoint, while the break in the δ18O data probably reflects the mixture of moisture sources with different isotopic characteristics. A sharp drop in the d-excess (>3‰) at the break in precipitation δ18O trend likely indicates a sudden switch from the Mediterranean moisture domain to additional (mainly Atlantic) influence, while a gradual change in the d-excess values might suggest a gradual increase of the non-Mediterranean moisture contribution along the transect. Full article
(This article belongs to the Special Issue Use of Water Stable Isotopes in Hydrological Process)
►▼ Show Figures

Figure 1

9 pages, 697 KiB  
Article
Crossroads of Continents and Modern Boundaries: An Introduction to Inuit and Chukchi Experiences in the Bering Strait, Beaufort Sea, and Baffin Bay
by Henry P. Huntington, Richard Binder Sr., Robert Comeau, Lene Kielsen Holm, Vera Metcalf, Toku Oshima, Carla SimsKayotuk and Eduard Zdor
Water 2020, 12(6), 1808; https://doi.org/10.3390/w12061808 - 24 Jun 2020
Cited by 4 | Viewed by 4968
Abstract
The homeland of Inuit extends from Asia and the Bering Sea to Greenland and the Atlantic Ocean. Inuit and their Chukchi neighbors have always been highly mobile, but the imposition of three international borders in the region constrained travel, trade, hunting, and resource [...] Read more.
The homeland of Inuit extends from Asia and the Bering Sea to Greenland and the Atlantic Ocean. Inuit and their Chukchi neighbors have always been highly mobile, but the imposition of three international borders in the region constrained travel, trade, hunting, and resource stewardship among neighboring groups. Colonization, assimilation, and enforcement of national laws further separated those even from the same family. In recent decades, Inuit and Chukchi have re-established many ties across those boundaries, making it easier to travel and trade with one another and to create new institutions of environmental management. To introduce Indigenous perspectives into the discussion of transboundary maritime water connections in the Arctic, this paper presents personal descriptions of what those connections mean to people who live and work along and across each of the national frontiers within the region: Russia–U.S., U.S.–Canada, and Canada–Greenland. Some of these connections have been made in cooperation with national governments, some in the absence of government activity, and some despite opposition from national governments. In all cases, the shared culture of the region has provided a common foundation for a shared vision and commitment to cooperation and the resumption of Indigenous self-determination within their homelands. Full article
(This article belongs to the Special Issue Transboundary Water Governance: New Sights and Developments)
►▼ Show Figures

Figure 1

30 pages, 10379 KiB  
Article
A Dynamic Comparison Sustainability Study of Standard Wastewater Treatment System in the Straw Pulp Papermaking Process and Printing & Dyeing Papermaking Process Based on the Hybrid Neural Network and Emergy Framework
by Junxue Zhang, Lin Ma and Yanyan Yan
Water 2020, 12(6), 1781; https://doi.org/10.3390/w12061781 - 23 Jun 2020
Cited by 11 | Viewed by 3134
Abstract
Sustainability study of the standard wastewater treatment system is the pivotal procedure in the water protection field. In order to better study the sustainability of sewage treatment systems, wastewater treatment system of straw pulp papermaking (WTSPP) and wastewater treatment system of printing and [...] Read more.
Sustainability study of the standard wastewater treatment system is the pivotal procedure in the water protection field. In order to better study the sustainability of sewage treatment systems, wastewater treatment system of straw pulp papermaking (WTSPP) and wastewater treatment system of printing and dyeing and papermaking (WTPDP) have been selected to assess the sustainable level in China. Based on the hybrid neural network and emergy framework, WTSPP and WTPDP were considered and analyzed in this paper. Therein, three types of indicators were used to evaluate these two systems, including basic structure emergy indicators (BEI), functional emergy indicators (FEI), and eco-efficiency emergy indicators (EEI). Through the basic neural network model and detailed neural network model design, the iteration paths and algorithm operation diagram of WTSPP and WTPDP were designed and realized in this article. Primary contents include: (1) For WTSPP and WTPDP, nonrenewable resources emergy are both the primary contributor and account for roughly 62.5% and 53.7%, respectively. (2) As the important indicator group, the environmental loading ratio (ELR) is 176 in the WTSPP and 323 in the WTPDP, respectively. Emergy sustainability indicators (ESIs) in the WTSPP and WTPDP, are 0.015 and 0.014, respectively. (3) Depending on fluctuation degrees, WTSPP is better than WTPDP. The maximum fluctuation ranges of WTSPP and WTPDP are (3%, −27%) and (28%, 61%), respectively. (4) All neural network analysis results manifest that the emergy sustainability indicators (ESIs) of WTSPP and WTPDP are [0.0151, 0.011] and [0.0179, 0.0055] in view of a long-term predictive view, respectively. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
►▼ Show Figures

Figure 1

10 pages, 3469 KiB  
Article
Measurement of Wastewater Discharge in Sewer Pipes Using Image Analysis
by Hyon Wook Ji, Sung Soo Yoo, Bong-Jae Lee, Dan Daehyun Koo and Jeong-Hee Kang
Water 2020, 12(6), 1771; https://doi.org/10.3390/w12061771 - 22 Jun 2020
Cited by 24 | Viewed by 5903
Abstract
Generally, the amount of wastewater in sewerage pipes is measured using sensor-based devices such as submerged area velocity flow meters or non-contact flow meters. However, these flow meters do not provide accurate measurements because of impurities, corrosion, and measurement instability due to high [...] Read more.
Generally, the amount of wastewater in sewerage pipes is measured using sensor-based devices such as submerged area velocity flow meters or non-contact flow meters. However, these flow meters do not provide accurate measurements because of impurities, corrosion, and measurement instability due to high turbidity. However, cameras have advantages such as their low cost, easy service, and convenient operation compared to the sensors. Therefore, in this study, we examined the following three methods for measuring the flow rate by capturing images inside of a sewer pipe using a camera and analyzing the images to calculate the water level: direct visual inspection and recording, image processing, and deep learning. The MATLAB image processing toolbox was used for analysis. The image processing found the boundary line by adjusting the contrast of the image or removing noise; a network to find the boundary line between wastewater and sewer pipe was created after training the image segmentation results and placing them into three categories using deep learning. From the recognized water levels, geometrical features were used to identify the boundary lines, and flow velocities and flow rates were calculated from Manning’s equation. Using direct inspection and image-processing techniques, boundary lines in images were detected at rates of 12% and 53%, respectively. Although the deep-learning model required training, it demonstrated 100% water-level detection, thereby proving to be the most advantageous method. Moreover, there is enough potential to increase the accuracy of deep learning, and it can be a possible replacement for existing flow measurement sensors. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
►▼ Show Figures

Figure 1

14 pages, 2548 KiB  
Article
Analysis of the Possibility of Using the Plain CFD Model to Simulate Two-Phase Flows in Spatial Systems of Pressure Sewer Networks
by Piotr Siwicki, Marcin Krukowski, Jan Studziński, Bartosz Szeląg and Rafał Wojciechowski
Water 2020, 12(6), 1779; https://doi.org/10.3390/w12061779 - 22 Jun 2020
Cited by 2 | Viewed by 2374
Abstract
The paper analyzes the possibility of using the CFD (Computational Fluid Dynamics) method to predict the amount of sewage remaining in siphons after a full air blast of the pressure sewer system. For this purpose, the results from measurements carried out on a [...] Read more.
The paper analyzes the possibility of using the CFD (Computational Fluid Dynamics) method to predict the amount of sewage remaining in siphons after a full air blast of the pressure sewer system. For this purpose, the results from measurements carried out on a laboratory installation were compared with the results obtained from modelling using a spatial model (3D) and a plain model (2D) of the installation. To determine these models, the structure of the VOF (Volume of Fluid) model was used in the CFD method. The simulation calculations carried out make it possible to state that the use of the plain model with the development of the installation modelled in the plan does not result in significant deterioration of the obtained results. The possibility of using 2D models for modelling pumped sewer systems allows for a significant shortening of the calculation time, which, in practice, results in the possibility of modelling much larger and longer installations than is possible with 3D models. Full article
(This article belongs to the Special Issue Numerical Modeling and Simulation of Multi-Phase Flows)
►▼ Show Figures

Figure 1

10 pages, 2006 KiB  
Article
Water Resource Systems Analysis for Water Scarcity Management: The Thames Water Case Study
by Mark Morley and Dragan Savić
Water 2020, 12(6), 1761; https://doi.org/10.3390/w12061761 - 20 Jun 2020
Cited by 6 | Viewed by 5874
Abstract
Optimisation tools are a practical solution to problems involving the complex and interdependent constituents of water resource systems and offer the opportunity to engage with practitioners as an integral part of the optimisation process. A multiobjective genetic algorithm is employed in conjunction with [...] Read more.
Optimisation tools are a practical solution to problems involving the complex and interdependent constituents of water resource systems and offer the opportunity to engage with practitioners as an integral part of the optimisation process. A multiobjective genetic algorithm is employed in conjunction with a detailed water resource model to optimise the “Lower Thames Control Diagram”, a set of control curves subject to a large number of constraints. The Diagram is used to regulate abstraction of water for the public drinking water supply for London, UK, and to maintain downstream environmental and navigational flows. The optimisation is undertaken with the aim of increasing the amount of water that can be supplied (deployable output) through solely operational changes. A significant improvement of 33 Ml/day (1% or £59.4 million of equivalent investment in alternative resources) of deployable output was achieved through the optimisation, improving the performance of the system whilst maintaining the level of service constraints without negatively impacting on the amount of water released downstream. A further 0.2% (£11.9 million equivalent) was found to be realisable through an additional low-cost intervention. A more realistic comparison of solutions indicated even larger savings for the utility, as the baseline solution did not satisfy the basic problem constraints. The optimised configuration of the Lower Thames Control Diagram was adopted by the water utility and the environmental regulators and is currently in use. Full article
(This article belongs to the Special Issue Application of the Systems Approach to the Management of Complex Water Systems)
►▼ Show Figures

Figure 1

20 pages, 3942 KiB  
Article
Experimental Characterization of the Hydraulic Jump Profile and Velocity Distribution in a Stilling Basin Physical Model
by Juan Francisco Macián-Pérez, Francisco José Vallés-Morán, Santiago Sánchez-Gómez, Marco De-Rossi-Estrada and Rafael García-Bartual
Water 2020, 12(6), 1758; https://doi.org/10.3390/w12061758 - 20 Jun 2020
Cited by 18 | Viewed by 4685
Abstract
The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy [...] Read more.
The study of the hydraulic jump developed in stilling basins is complex to a high degree due to the intense velocity and pressure fluctuations and the significant air entrainment. It is this complexity, bound to the practical interest in stilling basins for energy dissipation purposes, which brings the importance of physical modeling into the spotlight. However, despite the importance of stilling basins in engineering, bibliographic studies have traditionally focused on the classical hydraulic jump. Therefore, the objective of this research was to study the characteristics of the hydraulic jump in a typified USBR II stilling basin, through a physical model. The free surface profile and the velocity distribution of the hydraulic jump developed within this structure were analyzed in the model. To this end, an experimental campaign was carried out, assessing the performance of both, innovative techniques such as the time-of-flight camera and traditional instrumentation like the Pitot tube. The results showed a satisfactory representation of the free surface profile and the velocity distribution, despite some discussed limitations. Furthermore, the instrumentation employed revealed the important influence of the energy dissipation devices on the flow properties. In particular, relevant differences were found for the hydraulic jump shape and the maximum velocity positions within the measured vertical profiles, when compared to classical hydraulic jumps. Full article
(This article belongs to the Special Issue Physical Modelling in Hydraulics Engineering)
►▼ Show Figures

Figure 1

19 pages, 3282 KiB  
Article
Rainfall Variability and Trend Analysis of Rainfall in West Africa (Senegal, Mauritania, Burkina Faso)
by Zeineddine Nouaceur and Ovidiu Murarescu
Water 2020, 12(6), 1754; https://doi.org/10.3390/w12061754 - 19 Jun 2020
Cited by 28 | Viewed by 4950
Abstract
This study concerns the West African Sahel. The Sahelian climate is characterized by a long dry season and a rainy season which starts in June and ends in September–October. This latter season is associated with the process of oceanic moisture transfer to the [...] Read more.
This study concerns the West African Sahel. The Sahelian climate is characterized by a long dry season and a rainy season which starts in June and ends in September–October. This latter season is associated with the process of oceanic moisture transfer to the mainland (the West African Monsoon). This movement is governed by an overall moving of the meteorological equator and its low-pressure corridor (Intertropical Convergence Zone, ITCZ) towards the north, under the effect of the attraction of the Saharan thermal depressions and a greater vigor of the anticyclonic nuclei. This study was conducted on 27 Sahelian climatic stations in three countries (Burkina Faso, Mauritania, and Senegal). The method used to determine the modes of this variability and the trends of rainfall is the chronological graphic method of information processing (MGCTI) of the “Bertin Matrix” and continuous wavelets transform (CWT). Results show a rain resumption observed in the recent years over the Sahelian region and a convincing link with the surface temperature of the Atlantic Ocean. Full article
(This article belongs to the Special Issue Water Quality of Freshwater Ecosystems in a Temperate Climate)
►▼ Show Figures

Figure 1

31 pages, 3862 KiB  
Article
Improving Inter-Laboratory Reproducibility in Measurement of Biochemical Methane Potential (BMP)
by Sasha D. Hafner, Hélène Fruteau de Laclos, Konrad Koch and Christof Holliger
Water 2020, 12(6), 1752; https://doi.org/10.3390/w12061752 - 19 Jun 2020
Cited by 52 | Viewed by 6911
Abstract
Biochemical methane potential (BMP) tests used to determine the ultimate methane yield of organic substrates are not sufficiently standardized to ensure reproducibility among laboratories. In this contribution, a standardized BMP protocol was tested in a large inter-laboratory project, and results were used to [...] Read more.
Biochemical methane potential (BMP) tests used to determine the ultimate methane yield of organic substrates are not sufficiently standardized to ensure reproducibility among laboratories. In this contribution, a standardized BMP protocol was tested in a large inter-laboratory project, and results were used to quantify sources of variability and to refine validation criteria designed to improve BMP reproducibility. Three sets of BMP tests were carried out by more than thirty laboratories from fourteen countries, using multiple measurement methods, resulting in more than 400 BMP values. Four complex but homogenous substrates were tested, and additionally, microcrystalline cellulose was used as a positive control. Inter-laboratory variability in reported BMP values was moderate. Relative standard deviation among laboratories (RSDR) was 7.5 to 24%, but relative range (RR) was 31 to 130%. Systematic biases were associated with both laboratories and tests within laboratories. Substrate volatile solids (VS) measurement and inoculum origin did not make major contributions to variability, but errors in data processing or data entry were important. There was evidence of negative biases in manual manometric and manual volumetric measurement methods. Still, much of the observed variation in BMP values was not clearly related to any of these factors and is probably the result of particular practices that vary among laboratories or even technicians. Based on analysis of calculated BMP values, a set of recommendations was developed, considering measurement, data processing, validation, and reporting. Recommended validation criteria are: (i) test duration at least 1% net 3 d, (ii) relative standard deviation for cellulose BMP not higher than 6%, and (iii) mean cellulose BMP between 340 and 395 NmLCH4 gVS−1. Evidence from this large dataset shows that following the recommendations—in particular, application of validation criteria—can substantially improve reproducibility, with RSDR < 8% and RR < 25% for all substrates. The cellulose BMP criterion was particularly important. Results show that is possible to measure very similar BMP values with different measurement methods, but to meet the recommended validation criteria, some laboratories must make changes to their BMP methods. To help improve the practice of BMP measurement, a new website with detailed, up-to-date guidance on BMP measurement and data processing was established. Full article
(This article belongs to the Special Issue Biomethane Potential Tests—A Key Tool for Anaerobic Digestion Research and Practice)
►▼ Show Figures

Figure 1

15 pages, 552 KiB  
Article
Scarce Water Resources and Cereal Import Dependency: The Role of Integrated Water Resources Management
by Bente Castro Campos, Yanjun Ren and Jens-Peter Loy
Water 2020, 12(6), 1750; https://doi.org/10.3390/w12061750 - 19 Jun 2020
Cited by 4 | Viewed by 3671
Abstract
This study globally analyzes the nonlinear relationship between cereal import dependency and total renewable water resources per capita by testing for potential thresholds in water resources. Data are from the Food and Agriculture Organization (FAO), and consider the years of 2002, 2007, and [...] Read more.
This study globally analyzes the nonlinear relationship between cereal import dependency and total renewable water resources per capita by testing for potential thresholds in water resources. Data are from the Food and Agriculture Organization (FAO), and consider the years of 2002, 2007, and 2012. The results show evident ceiling effects with a threshold of 1588 m3/(capita/year) in the multiple predictor model. Above this value, the total renewable water resources per capita no longer have a considerable effect on cereal import dependency. Importantly, we found that if integrated water resource management improves, cereal import dependency will increase for countries with total renewable water resources per capita between 1588 m3/(capita/year) and 5000 m3/(capita/year), but not for countries below or equal to the threshold of 1588 m3/(capita/year). Water-scarce countries above the threshold use cereal imports as a coping strategy to save limited national water resources. This strategy might be suggested to extremely water-scarce countries below the threshold to increase their water use efficiency. Global solidarity of grain exporters with water-scarce countries is required to guarantee their food security, while water-scarce countries need to overcome their skepticism of foreign dominance through food imports. Full article
(This article belongs to the Section Water Resources Management, Policy and Governance)
►▼ Show Figures

Figure 1

18 pages, 4833 KiB  
Article
Retrieval of Soil Moisture by Integrating Sentinel-1A and MODIS Data over Agricultural Fields
by Yizhi Han, Xiaojing Bai, Wei Shao and Jie Wang
Water 2020, 12(6), 1726; https://doi.org/10.3390/w12061726 - 17 Jun 2020
Cited by 21 | Viewed by 3577
Abstract
Soil moisture is an essential variable in the land surface ecosystem, which plays an important role in agricultural drought monitoring, crop status monitoring, and crop yield prediction. High-resolution radar data can be combined with optical remote-sensing data to provide a new approach to [...] Read more.
Soil moisture is an essential variable in the land surface ecosystem, which plays an important role in agricultural drought monitoring, crop status monitoring, and crop yield prediction. High-resolution radar data can be combined with optical remote-sensing data to provide a new approach to estimate high-resolution soil moisture over vegetated areas. In this paper, the Sentinel-1A data and the Moderate Resolution Imaging Spectroradiometer (MODIS) data are combined to retrieve soil moisture over agricultural fields. The advanced integral equation model (AIEM) is utilized to calculate the scattering contribution of the bare soil surface. The water cloud model (WCM) is applied to model the backscattering coefficient of vegetated areas, which use two vegetation parameters to parameterize the scattering and attenuation properties of vegetation. Four different vegetation parameters extracted from MODIS products are combined to predict the scattering contribution of vegetation, including the leaf area index (LAI), the fraction of photosynthetically active radiation (FPAR), normalized difference vegetation index (NDVI), and the enhanced vegetation index (EVI). The effective roughness parameters are chosen to parameterize the AIEM. The Sentinel-1A and MODIS data in 2017 are used to calibrate the coupled model, and the datasets in 2018 are used for soil moisture estimation. The calibration results indicate that the Sentinel-1A backscattering coefficient can be accurately predicted by the coupled model with the Pearson correlation coefficient (R) ranging from 0.58 to 0.81 and a root mean square error (RMSE) ranging from 0.996 to 1.401 dB. The modeled results show that the retrieved soil moisture can capture the seasonal dynamics of soil moisture with R ranging from 0.74 to 0.81. With the different vegetation parameter combinations used for parameterizing the scattering contribution of the canopy, the importance of suitable vegetation parameters for describing the scattering and attenuation properties of vegetation is confirmed. The LAI is recommended to characterize the scattering properties. There is no obvious clue for selecting vegetation descriptors to characterize the attenuation properties of vegetation. These promising results confirm the feasibility and validity of the coupled model for soil moisture retrieval from the Sentinel-1A and MODIS data. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

18 pages, 2420 KiB  
Article
Snowmelt-Driven Streamflow Prediction Using Machine Learning Techniques (LSTM, NARX, GPR, and SVR)
by Samit Thapa, Zebin Zhao, Bo Li, Lu Lu, Donglei Fu, Xiaofei Shi, Bo Tang and Hong Qi
Water 2020, 12(6), 1734; https://doi.org/10.3390/w12061734 - 17 Jun 2020
Cited by 50 | Viewed by 6064
Abstract
Although machine learning (ML) techniques are increasingly popular in water resource studies, they are not extensively utilized in modeling snowmelt. In this study, we developed a model based on a deep learning long short-term memory (LSTM) for snowmelt-driven discharge modeling in a Himalayan [...] Read more.
Although machine learning (ML) techniques are increasingly popular in water resource studies, they are not extensively utilized in modeling snowmelt. In this study, we developed a model based on a deep learning long short-term memory (LSTM) for snowmelt-driven discharge modeling in a Himalayan basin. For comparison, we developed the nonlinear autoregressive exogenous model (NARX), Gaussian process regression (GPR), and support vector regression (SVR) models. The snow area derived from moderate resolution imaging spectroradiometer (MODIS) snow images along with remotely sensed meteorological products were utilized as inputs to the models. The Gamma test was conducted to determine the appropriate input combination for the models. The shallow LSTM model with a hidden layer achieved superior results than the deeper LSTM models with multiple hidden layers. Out of seven optimizers tested, Adamax proved to be the aptest optimizer for this study. The evaluation of the ML models was done by the coefficient of determination (R2), mean absolute error (MAE), modified Kling–Gupta efficiency (KGE’), Nash–Sutcliffe efficiency (NSE), and root-mean-squared error (RMSE). The LSTM model (KGE’ = 0.99) enriched with snow cover input achieved the best results followed by NARX (KGE’ = 0.974), GPR (KGE’ = 0.95), and SVR (KGE’ = 0.949), respectively. The outcome of this study proves the applicability of the ML models, especially the LSTM model, in predicting snowmelt driven discharge in the data-scant mountainous watersheds. Full article
(This article belongs to the Section Hydrology)
►▼ Show Figures

Figure 1

18 pages, 2765 KiB  
Article
Effects of Land Use Changes on Streamflow and Sediment Yield in Atibaia River Basin—SP, Brazil
by Franciane Mendonça dos Santos, Rodrigo Proença de Oliveira and José Augusto Di Lollo
Water 2020, 12(6), 1711; https://doi.org/10.3390/w12061711 - 16 Jun 2020
Cited by 18 | Viewed by 3927
Abstract
The Soil and Water Assessment Tool (SWAT) is often used to evaluate the impacts of different land use scenarios on streamflow and sediment yield, but there is a need for some clear recommendations on how to select the parameter set that defines a [...] Read more.
The Soil and Water Assessment Tool (SWAT) is often used to evaluate the impacts of different land use scenarios on streamflow and sediment yield, but there is a need for some clear recommendations on how to select the parameter set that defines a given land use scenario and on what is the most appropriate methodology to change the selected parameters when describing possible future conditions. This paper reviews the SWAT formulation to identify the parameters that depend on the land use, performs a sensitivity analysis to determine the ones with larger impacts on the model results and discusses ways to consider future land use conditions. The case study is the Atibaia river basin, with 2838 km2 (São Paulo, Brazil). The parameters identified by sensitivity analysis with the largest impacts on streamflow and sediment yield were the initial curve number for moisture condition II (CN), maximum canopy storage for each land use (CANMX) and the cover and management factor (USLE_C). The identification and appropriate parameter change can provide real estimates of the magnitudes in the land use changes, which were verified in this study. Such information can be used as an instrument for proposing improvements in the basin’s environmental quality and management. Full article
(This article belongs to the Special Issue Hydrological Impacts of Climate Change and Land Use)
►▼ Show Figures

Figure 1

19 pages, 6689 KiB  
Article
The Link between Permeable Interlocking Concrete Pavement (PICP) Design and Nutrient Removal
by Bodi Kimberly Liu and Neil P. Armitage
Water 2020, 12(6), 1714; https://doi.org/10.3390/w12061714 - 16 Jun 2020
Cited by 9 | Viewed by 3926
Abstract
The construction of ‘hard’ impermeable surfaces in urban areas results in the increased flow of stormwater runoff and its associated pollutants into downstream receiving waters. Permeable Pavement Systems (PPS) can help mitigate this. The most common type of PPS in South Africa is [...] Read more.
The construction of ‘hard’ impermeable surfaces in urban areas results in the increased flow of stormwater runoff and its associated pollutants into downstream receiving waters. Permeable Pavement Systems (PPS) can help mitigate this. The most common type of PPS in South Africa is permeable interlocking concrete pavement (PICP), but there is currently insufficient information available on the relative treatment performance of different PICP designs. This paper describes an investigation into the performance of ten different PICP systems constructed in the Civil Engineering Laboratory at the University of Cape Town for the treatment of various nutrients commonly found in stormwater runoff. It was found that removal efficiencies ranged from 27.5% to 78.7% for ammonia-nitrogen and from −37% to 11% for orthophosphate-phosphorus; whilst 4% to 20.2% more nitrite-nitrogen and 160% to 2580% more nitrate-nitrogen were simultaneously added. The presence of a geotextile resulted in higher ammonia-nitrogen removal efficiencies but also higher nitrate-nitrogen addition than those cells without—with small differences between various types. The cell with a permanently wet ‘sump’ had the highest nitrate-nitrogen addition of all. Lower pH results in higher nitrate-nitrogen concentrations, whilst the electrical conductivity strongly depends on the length of the periods between rainfall ‘seasons’, decreasing rapidly during wet periods but increasing during dry periods. Paver type also had a minor impact on nutrient removal. Full article
(This article belongs to the Special Issue Permeable Pavement Systems: Advances and Challenges in Stormwater Management)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying article 901-950 on page 19 of 26.

Go to page    first_page chevron_left 17 18 19 20 21 chevron_right last_page
Back to TopTop