Open AccessArticle
Bayesian Hierarchical Regression to Assess Variation of Stream Temperature with Atmospheric Temperature in a Small Watershed
Hydrology 2017, 4(3), 44; doi:10.3390/hydrology4030044 -
Abstract
This paper described the variability of stream temperature, Ts, and compared relationships between Ts and air temperature, Ta, at 10 sites along a 1.2 km reach in a 2 km2 basin in New Jersey, USA, using Bayesian
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This paper described the variability of stream temperature, Ts, and compared relationships between Ts and air temperature, Ta, at 10 sites along a 1.2 km reach in a 2 km2 basin in New Jersey, USA, using Bayesian Hierarchical Regression. Mean daily mean Ts was significantly cooler at two sites and significantly warmer at three sites relative to the mean daily Ts for all sites combined. Seasonal daily mean Ts showed the greatest variation between sites in the summer within the reach for both daily mean and daily maximum temperatures. Posterior distributions for slope parameters (βj) for regressions varied significantly by season and showed the greatest variation in summer. The strongest relationships occurred in autumn with β=0.743±0.019 (β=0.712±0.022), and the weakest relationships occurred in the summer with β=0.254±0.030 (β=0.193±0.039). Results support the conclusion that riparian shading impacts the effect of Ta on Ts, and that Ts shows a stronger relationship with measured Ta at sites in open areas that are more likely to have meteorologic conditions similar to bulk conditions. Full article
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Open AccessArticle
Differences in Stream Water Nitrate Concentrations between a Nitrogen-Saturated Upland Forest and a Downstream Mixed Land Use River Basin
Hydrology 2017, 4(3), 43; doi:10.3390/hydrology4030043 -
Abstract
Nitrogen (N) saturation of upland forests has been assumed to be a substantial N source downstream. However, removal processes of N, including assimilation and denitrification in the downstream area, have not been clarified. To evaluate the N removal processes, nitrate (NO3
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Nitrogen (N) saturation of upland forests has been assumed to be a substantial N source downstream. However, removal processes of N, including assimilation and denitrification in the downstream area, have not been clarified. To evaluate the N removal processes, nitrate (NO3) and organic N concentrations, as well as nitrogen isotope ratio (δ15N) and oxygen isotope ratio (δ18O) of NO3 were measured along three rivers of Tatara River Basin, Japan where upland forests have already been N-saturated. Geographic information system (GIS) based topographical analysis was also conducted to evaluate the land use as urban area in relation to topography. In two of the three rivers, NO3 concentrations did not increase from upstream to downstream, despite the potential non-point N sources of urban areas. In another river, NO3 concentrations rather decreased. The values of δ15N and δ18O of NO3 and organic N concentrations suggested the presence of denitrification and assimilation over N pollutants in the river whose watersheds have a lower percentage of urban area. The lower percentage of urban area could be explained by the lower topographic index. This study concluded that the NO3 leaching from upland N-saturated forests was substantially assimilated or denitrified in the downstream area. Full article
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Open AccessReview
Groundwater Discharge in the Arctic: A Review of Studies and Implications for Biogeochemistry
Hydrology 2017, 4(3), 41; doi:10.3390/hydrology4030041 -
Abstract
Groundwater discharge, including submarine groundwater discharge, discharge to lakes and rivers, and subglacial discharge, affects freshwater and marine ecosystems across the globe. The implications for biogeochemistry include the transport of nutrients, metals, and gases to these systems. The Arctic is one region of
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Groundwater discharge, including submarine groundwater discharge, discharge to lakes and rivers, and subglacial discharge, affects freshwater and marine ecosystems across the globe. The implications for biogeochemistry include the transport of nutrients, metals, and gases to these systems. The Arctic is one region of the globe that has been understudied with respect to groundwater discharge until recently, when a handful of studies sought to understand the nature of groundwater discharge and its impacts on aquatic ecosystems. Those studies are summarized here, and the implications for biogeochemistry are synthesized. Carbon and nitrogen are the most frequently studied solutes with respect to groundwater discharge in the Arctic. The transport of carbon and nitrogen through groundwater discharge are discussed across study sites, and scientists expect their transport through this mechanism to significantly change with the onset of climate change. The Arctic is of special interest in terms of groundwater discharge, as climate change data predicts that it will warm faster than other environments. Lastly, the effects of climate change on the physical and biogeochemical aspects of groundwater discharge in the Arctic are discussed, as are research priorities. Full article
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Open AccessArticle
Lithological Identification and Underground Water Conditions in Jeddo Using Geophysical and Geochemical Methods
Hydrology 2017, 4(3), 42; doi:10.3390/hydrology4030042 -
Abstract
Resistivity soundings and hydrogeochemical methods were carried out in order to establish the characteristics of the aquifer in Jeddo, Southern Nigeria. Results of the resistivity sounding revealed that the formation is made up of clay, clayey sand, and fine- to coarse-grained sand. The
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Resistivity soundings and hydrogeochemical methods were carried out in order to establish the characteristics of the aquifer in Jeddo, Southern Nigeria. Results of the resistivity sounding revealed that the formation is made up of clay, clayey sand, and fine- to coarse-grained sand. The mean depth of the aquifer was obtained as 12.7 m while the aquifer resistivity ranged from 161 to 1728 Ωm. The mean value of transmissivity obtained for the aquifer is 169 m2 day−1 while analysis of the transmissivity revealed that about 6% of the study area has greatest potential for a productive aquifer. The study also revealed that the underground water flows in the northeast–southwest direction. The hydro geochemical analysis of water samples showed that some parameters such as lead, color and pH exceeded the permissible limits, which were established by Federal Environmental Protection Agency and the World Health Organization. It is concluded from the water quality index (WQI) that the groundwater is of poor quality and requires some remediation before it can be used for domestic and industrial purposes. Full article
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Open AccessArticle
Water Balance Analysis over the Niger Inland Delta-Mali: Spatio-Temporal Dynamics of the Flooded Area and Water Losses
Hydrology 2017, 4(3), 40; doi:10.3390/hydrology4030040 -
Abstract
The Niger Inland Delta (NID) wetland comprises a large flooded area that plays an important role in the ecosystem services. This study provides a comprehensive understanding of the NID’s hydro-climatological functioning using water balance approach. After a clear description of the water budget’s
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The Niger Inland Delta (NID) wetland comprises a large flooded area that plays an important role in the ecosystem services. This study provides a comprehensive understanding of the NID’s hydro-climatological functioning using water balance approach. After a clear description of the water budget’s elements specific to the NID catchment, a spatial and temporal dynamics of the annual flood across the NID over the period 2000–2009 was performed using data from satellite QuickSCAT and its associated sensor SeaWinds. The estimated areas were used along with observed discharge and remotely-sensed climatic data to quantitatively evaluate each water balance component. The results indicate: (i) a clear spatiotemporal of the flooded areas varied between 25,000 km2 in wet periods and 2000 km2 in dry periods; (ii) an average evapotranspiration loss of 17.31 km3 (43% of the total inflow) was assessed in the catchment; (iii) precipitation’s contribution to the NID’s budget totals 5.16 km3 (12.8% of the total inflow); and (iv) the contribution of return flow from irrigated fields totals 1.8 km3 (4.5% of the total inflow, among which 1.2 km3 are from Office du Niger) to the flooded areas, refined the NID’s water balance estimates. Knowledge gained on NID’s water balance analysis will be used to develop and calibrate hydrological models in the Niger Inland Delta of the basin. Full article
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Open AccessArticle
Hydrological Evaluation of Satellite and Reanalysis Precipitation Products in the Upper Blue Nile Basin: A Case Study of Gilgel Abbay
Hydrology 2017, 4(3), 39; doi:10.3390/hydrology4030039 -
Abstract
The aim of this study is to assess the performance of various global precipitation products for water resources application in the Upper Blue Nile basin, Ethiopia. Three precipitation products of gauge-adjusted (corrected) CMORPH, (TRMM) TMPA 3B42v7 and ECMWF reanalysis products are evaluated. A
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The aim of this study is to assess the performance of various global precipitation products for water resources application in the Upper Blue Nile basin, Ethiopia. Three precipitation products of gauge-adjusted (corrected) CMORPH, (TRMM) TMPA 3B42v7 and ECMWF reanalysis products are evaluated. A Coupled Routing and Excess Storage (CREST) distributed hydrological model is calibrated and used for the evaluation. The model is calibrated for 2000–2005 and validated for 2006–2011 periods using daily observed rainfall and discharge datasets. The results indicate the precipitation products consistently provide a better performance of runoff estimation when they are independently calibrated than simulation modes of the products. We conclude as long as each product is calibrated independently, global precipitation products can provide enough information for water resource management in data-scarce regions of upper Blue Nile Basin. Further analysis is underway to understand the response characteristics of the precipitation products at larger spatio-temporal scales. Full article
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Open AccessArticle
Trends and Changes in Recent and Future Penman-Monteith Potential Evapotranspiration in Benin (West Africa)
Hydrology 2017, 4(3), 38; doi:10.3390/hydrology4030038 -
Abstract
In this study, the recent variability of the annual potential evapotranspiration (PET) of six synoptic stations of Benin was carried out. The future changes of PET under RCP4.5 and RCP8.5 scenarios were also quantified under three different projected periods (P1 = 2011–2040, P2
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In this study, the recent variability of the annual potential evapotranspiration (PET) of six synoptic stations of Benin was carried out. The future changes of PET under RCP4.5 and RCP8.5 scenarios were also quantified under three different projected periods (P1 = 2011–2040, P2 = 2041–2070 and P3 = 2071–2100) compared to the reference period (1981–2010). The results show a high variability of PET at all stations over the baseline period with alternating of deficit and excess periods. The Representative Concentration Pathways (RCP4.5 and RCP8.5) scenarios indicate that annual PET gradually increase and reach its maximum on 2100. However, PET’s changes from the two forcing scenarios start to diverge only around 2070 and this divergence is maximal on 2100. The rates of changes related to the baseline period vary from 2 to 7% for P1 and both scenarios, 5 to 10% for P2 and both scenarios, 7 to 12% for P3 and RCP4.5 scenario and 15 to 20% for P3 and RCP8.5 scenario. At seasonal scale, the results show a progressive increase (from 15 to 25% related to the baseline period) of PET until 2100 for January, February, June, July and December. In April, May, August, September and October, there is a slight decrease (from −5 to 0%) of PET according to RCP4.5 scenario while there is a slight increase (0 to 5%) for RCP8.5 scenario. Full article
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Open AccessArticle
Groundwater Engineering in an Environmentally Sensitive Urban Area: Assessment, Landuse Change/Infrastructure Impacts and Mitigation Measures
Hydrology 2017, 4(3), 37; doi:10.3390/hydrology4030037 -
Abstract
A rise in the shallow unconfined groundwater at a site in Australia is causing water logging of the underground facility in the affected area. Realizing this problem, a study was conducted to identify the source of water that is causing the rise and
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A rise in the shallow unconfined groundwater at a site in Australia is causing water logging of the underground facility in the affected area. Realizing this problem, a study was conducted to identify the source of water that is causing the rise and to develop an implementation and operation plan of the mitigation (dewatering system). Modelling was undertaken using MODFLOW-SURFACT code, within the framework of Visual MODFLOW, to assess the spatial and temporal groundwater level at the site. The study undertaken incorporates compilation and assessment of available data, including a list of factual information reviewed, development of a conceptual groundwater model for the site and modelling of the pre and post development conditions. The outcomes of the assessment indicate water level rises due to the construction of the embankment are likely less than 0.12 m and changes in land, such as affected area burial, may change aquifer characteristics more significantly than the embankment. It is concluded that the elevated groundwater levels in the affected area are most likely a result of above average rainfall since 2007 and long term cumulative land use changes. The embankment construction is just one of many land use changes that have occurred both within and surrounding the affected area and likely only a minor contributor to the elevated water levels. Greater contribution may be attributed to re-direction of the natural flow paths the railway culvert weir reducing the overland flow gradient and ongoing changes (burial) within the affected area and including the embankment. The model findings gives answers on what factors may be/are causing/contributing to, the higher than usual groundwater levels in the study area. A combination of drainage and/or pumping (dewatering system) is suggested as a solution to overcome the problem of rising groundwater levels at the site. Further, the model output can aid in assessing mitigation options, including horizontal drainage networks and pumping to control for the rising water table conditions in the area, depending on the level of treatment and pathogenic criteria. Full article
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Open AccessArticle
Extreme Precipitation Indices Trend Assessment over the Upper Oueme River Valley-(Benin)
Hydrology 2017, 4(3), 36; doi:10.3390/hydrology4030036 -
Abstract
This study analyzed trends in extreme precipitation based on daily rainfall data provided by Bénin Méteo Agency for the Upper Ouémé valley in Benin over the period 1951–2014. Eleven indices divided into two groups were considered. The first group consists of frequency indices:
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This study analyzed trends in extreme precipitation based on daily rainfall data provided by Bénin Méteo Agency for the Upper Ouémé valley in Benin over the period 1951–2014. Eleven indices divided into two groups were considered. The first group consists of frequency indices: number of heavy rainfall days, very heavy rainfall days and extremely heavy rainfall days; and maximum number of Consecutive dry days and wet days. The second group concerns intensity: daily maximum rainfall (RX1day), maximum five-day rainfall (RX5day), annual total wet-day rainfall (PRCPTOT), simple daily intensity index (SDII), very wet day (R95P) and extremely wet day rainfall (R99P). The non-parametric Mann-Kendall test was used to assess trends in those indices. The results show that only 30% of the stations experienced decreasing trends for the number of heavy rainfall days (R10mm) and daily maximum rainfall (RX1day). For the annual total wet-day rainfall (PRCPTOT), the simple daily intensity index (SDII) and the very wet day rainfall (R95P), 20% of stations faced significant negative trends. In addition, the decreasing trends are observed for 10% stations considering the number of very heavy rainfall days (R20mm), the maximum five-day rainfall (RX5day) and the extremely wet day rainfall (R99P). About the increasing trend, 10% stations are identified for the number of consecutive dry days (CDD), very heavy rainfall days (R20mm), the daily maximum rainfall (RX1day), the simple daily intensity index, and the extremely wet day rainfall (R99P). These results show the absence of clear trend of climate indices evolution in almost all stations. Consequently, uncertainties in the evolution of rainfall indices must be taken into account in the definition of adaptation strategies for flood or drought risks. Similarly, these results show a slight drop in the dry sequences of the 1970s and 1980s revealed in the region by previous studies. Full article
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Open AccessArticle
“Cape Fear”—A Hybrid Hillslope Plot for Monitoring Hydrological Processes
Hydrology 2017, 4(3), 35; doi:10.3390/hydrology4030035 -
Abstract
Innovative experimental field designs and methods are instrumental for dissecting hydrological processes in hillslopes. However, experimental studies at the catchment scale are rarely affordable to most research groups, and laboratory flumes are oversimplified to reproduce natural phenomena. In this work, we present the
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Innovative experimental field designs and methods are instrumental for dissecting hydrological processes in hillslopes. However, experimental studies at the catchment scale are rarely affordable to most research groups, and laboratory flumes are oversimplified to reproduce natural phenomena. In this work, we present the innovative “hybrid” experimental plot of Cape Fear, which features controllable water fluxes and boundary conditions, but it is directly exposed to external atmospheric agents. We demonstrate the suitability of Cape Fear to study hydrological phenomena through a feasibility test, whereby the response of the plot to a natural storm is in line with the well-known hydrological response of natural hillslopes. Future studies will address the influence of the plot geometry parameters on rill formation. Full article
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Open AccessArticle
Evaluation of Variations in Frequency of Landslide Events Affecting Pyroclastic Covers in Campania Region under the Effect of Climate Changes
Hydrology 2017, 4(3), 34; doi:10.3390/hydrology4030034 -
Abstract
In recent years, pyroclastic covers mantling slopes in the Campania region of southern Italy have frequently been affected by flowslides. Due to high exposure and demographic pressure in these areas, assessment of the potential effects of climate change on the frequency of such
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In recent years, pyroclastic covers mantling slopes in the Campania region of southern Italy have frequently been affected by flowslides. Due to high exposure and demographic pressure in these areas, assessment of the potential effects of climate change on the frequency of such events has become a crucial issue. In this regard, our paper proposes a simulation chain comprising three main elements: (i) climate simulation at the highest horizontal resolution available for Italy (8 km); (ii) a bias correction procedure in an attempt to remove systematic errors in the entire weather forcing probability distribution; (iii) the data obtained used as input for an interpretative tool estimating the evolution of soil pore water pressure and water storage (bulk water content) by means of a well-calibrated coupled thermo-hydraulic approach able to adequately take into account soil-atmosphere interaction dynamics. The predictive ability of the geotechnical model to reproduce failure conditions was tested by forcing it with temperature and precipitation observations. Subsequently, the performance of the entire modeling chain was evaluated for a period from 1981 to 2010. Lastly, variations in landslide occurrence were assessed up to 2100 under two concentration scenarios. An increase with different features was estimated under both scenarios depending on the time horizon and the severity of the concentration scenario. Full article
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Open AccessArticle
Numerical Tests of the Lookup Table Method in Solving Richards’ Equation for Infiltration and Drainage in Heterogeneous Soils
Hydrology 2017, 4(3), 33; doi:10.3390/hydrology4030033 -
Abstract
The lookup table option, as an alternative to analytical calculation for evaluating the nonlinear heterogeneous soil characteristics, is introduced and compared for both the Picard and Newton iterative schemes in the numerical solution of Richards’ equation. The lookup table method can be a
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The lookup table option, as an alternative to analytical calculation for evaluating the nonlinear heterogeneous soil characteristics, is introduced and compared for both the Picard and Newton iterative schemes in the numerical solution of Richards’ equation. The lookup table method can be a cost-effective alternative to analytical evaluation in the case of heterogeneous soils, but it has not been examined in detail in the hydrological modeling literature. Three layered soil test problems are considered, and the robustness and accuracy of the lookup table approach are assessed for uniform and non-uniform distributions of lookup points in the soil moisture retention curves. Results from the three one-dimensional test simulations show that the uniform distributed option gives improved convergence and robustness for the drainage problem compared to the non-uniform strategy. On the other hand, the non-uniform technique can be chosen for test problems involving flow into initially dry layered soils. Full article
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Open AccessArticle
Studying Water Quality Using Socio-Environmental Synthesis Approach: A Case Study in Baltimore’s Watershed
Hydrology 2017, 4(2), 32; doi:10.3390/hydrology4020032 -
Abstract
While almost 87% of the world’s population now has access to an improved drinking water source, the risk of water pollution remains, often due to environmental factors such as increasing urbanization and industrialization. Last year, as the country watched the tragic Flint, Michigan
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While almost 87% of the world’s population now has access to an improved drinking water source, the risk of water pollution remains, often due to environmental factors such as increasing urbanization and industrialization. Last year, as the country watched the tragic Flint, Michigan tap water quality deterioration unfold, the issue was brought closer to home: How good is Baltimore’s water system? Baltimore’s water source is primarily surface water, which feeds into the Liberty, Loch Raven and Prettyboy reservoirs. The Socio-Environmental Synthesis (SES) approach was used to investigate the factors that contribute to water quality impairment. SES is a research method that integrates existing knowledge and data from natural and social sciences to advance understanding of socio-environmental systems. The study found out that while the quality of the drinking water is generally good, there is a growing concern with the quality of water in the watersheds. The high levels of nitrate-nitrogen and increased concentrations of carbon dioxide are especially alarming. The high levels of Biological Oxygen Demand are also good indicators of the intensity of agriculture and urbanization in the watersheds. This study believes that maximizing the current watershed conservation and restoration efforts would reduce the treatment costs and safeguard the urban water supplies. Full article
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Open AccessCase Report
Flood Response System—A Case Study
Hydrology 2017, 4(2), 30; doi:10.3390/hydrology4020030 -
Abstract
Flood Response System (FRS) is a network-enabled solution developed using open-source software. The system has query based flood damage assessment modules with outputs in the form of spatial maps and statistical databases. FRS effectively facilitates the management of post-disaster activities caused due to
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Flood Response System (FRS) is a network-enabled solution developed using open-source software. The system has query based flood damage assessment modules with outputs in the form of spatial maps and statistical databases. FRS effectively facilitates the management of post-disaster activities caused due to flood, like displaying spatial maps of area affected, inundated roads, etc., and maintains a steady flow of information at all levels with different access rights depending upon the criticality of the information. It is designed to facilitate users in managing information related to flooding during critical flood seasons and analyzing the extent of damage. The inputs to FRS are provided using two components: (1) a semi-automated application developed indigenously, to delineate inundated areas for Near-Real Time Flood Monitoring using Active Microwave Remote Sensing data and (2) a two-dimensional (2D) hydrodynamic river model generated outputs for water depth and velocity in flooded areas for an embankment breach scenario. The 2D Hydrodynamic model, CCHE2D (Center for Computational Hydroscience and Engineering Two-Dimensional model), was used to simulate an area of 600 km2 in the flood-prone zone of the Brahmaputra basin. The resultant inundated area from the model was found to be 85% accurate when validated with post-flood optical satellite data. Full article
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Open AccessArticle
Advancing Understanding of the Surface Water Quality Regime of Contemporary Mixed-Land-Use Watersheds: An Application of the Experimental Watershed Method
Hydrology 2017, 4(2), 31; doi:10.3390/hydrology4020031 -
Abstract
A representative watershed was instrumented with five gauging sites (n = 5), partitioning the catchment into five nested-scale sub-watersheds. Four physiochemical variables were monitored: water temperature, pH, total dissolved solids (TDS), and dissolved oxygen (DO). Data were collected four days per week
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A representative watershed was instrumented with five gauging sites (n = 5), partitioning the catchment into five nested-scale sub-watersheds. Four physiochemical variables were monitored: water temperature, pH, total dissolved solids (TDS), and dissolved oxygen (DO). Data were collected four days per week from October 2010–May 2014 at each gauging site. Statistical analyses indicated significant differences (p < 0.05) between nearly every monitoring site pairing for each physiochemical variable. The water temperature regime displayed a threshold/step-change condition, with an upshifted and more variable regime attributable to the impacts of urban land uses. TDS, pH, and DO displayed similar spatiotemporal trends, with increasing median concentrations from site #1 (agriculture) to #3 (mixed-use urban) and decreasing median concentrations from site #3 to #5 (suburban). Decreasing concentrations and increasing streamflow volume with stream distance, suggest the contribution of dilution processes to the physiochemical regime of the creek below urban site #3. DO concentrations exceeded water quality standards on an average of 31% of observation days. Results showed seasonal trends for each physiochemical parameter, with higher TDS, pH, and DO during the cold season (November–April) relative to the warm season (May–October). Multivariate modeling results emphasize the importance of the pH/DO relationship in these systems, and demonstrate the potential utility of a simple two factor model (water temperature and pH) in accurately predicting DO. Collectively, results highlight the interacting influences of natural (autotrophic photosynthesis, organic detritus loading) and anthropogenic (road salt application) factors on the physiochemical regime of mixed-land-use watersheds. Full article
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Open AccessArticle
Analysis of Precipitation and Drought Data in Hexi Corridor, Northwest China
Hydrology 2017, 4(2), 29; doi:10.3390/hydrology4020029 -
Abstract
Precipitation data from nine meteorological stations in arid oases of Hexi Corridor, northwest China during 1970–2012 were analyzed to detect trends in precipitation and Standardized Precipitation Index (SPI) at multiple time scales using linear regression, Mann–Kendall and Spearman’s Rho tests. The results found
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Precipitation data from nine meteorological stations in arid oases of Hexi Corridor, northwest China during 1970–2012 were analyzed to detect trends in precipitation and Standardized Precipitation Index (SPI) at multiple time scales using linear regression, Mann–Kendall and Spearman’s Rho tests. The results found that annual precipitation in the observed stations was rare and fell into the arid region category according to the aridity index analysis. The monthly analysis of precipitation found that three stations showed significant increasing trends in different months, while on the annual level, only Yongchang station had a significant increasing trend. The analysis of SPI-12 found three main drought intervals, i.e., 1984–1987, 1991–1992 and 2008–2011, and an extremely dry year among the stations was recorded in 1986; the southeast and middle portions of the study area are expected to have more precipitation and less dry conditions. Full article
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Open AccessArticle
Understanding the Effects of Parameter Uncertainty on Temporal Dynamics of Groundwater-Surface Water Interaction
Hydrology 2017, 4(2), 28; doi:10.3390/hydrology4020028 -
Abstract
This study presents the understanding of temporal dynamics of groundwater-surface water (GW-SW) interaction due to parameter uncertainty by using a physically-based and distributed gridded surface subsurface hydrologic analysis (GSSHA) model combined with a Monte Carlo simulation. A study area along the main stem
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This study presents the understanding of temporal dynamics of groundwater-surface water (GW-SW) interaction due to parameter uncertainty by using a physically-based and distributed gridded surface subsurface hydrologic analysis (GSSHA) model combined with a Monte Carlo simulation. A study area along the main stem of the Kiskatinaw River of the Kiskatinaw River watershed, Northeast British Columbia, Canada, was used as a case study. Two different greenhouse gas (GHG) emission scenarios (i.e., A2: heterogeneous world with self-reliance and preservation of local identities, and B1: a more integrated and environmental-friendly world) of the Special Report on Emissions Scenarios (SRES) from the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) for 2013 were used as case scenarios. Before conducting uncertainty analysis, a sensitivity analysis was performed to find the most sensitive parameters to the model output (i.e., mean monthly groundwater contribution to stream flow). Then, a Monte Carlo simulation was used to conduct the uncertainty analysis. The uncertainty analysis results under both case scenarios revealed that the pattern of the cumulative relative frequency distribution of the mean monthly and annual groundwater contributions to stream flow varied monthly and annually, respectively, due to the uncertainties of the sensitive model parameters. In addition, the pattern of the cumulative relative frequency distribution of a particular month’s groundwater contribution to the stream flow differed significantly between both scenarios. These results indicated the complexities and uncertainties in the GW-SW interaction system. Therefore, it is of necessity to use such uncertainty analysis results rather than the point estimates for better water resources management decision-making. Full article
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Open AccessArticle
Comparison of SWAT and GSSHA for High Time Resolution Prediction of Stream Flow and Sediment Concentration in a Small Agricultural Watershed
Hydrology 2017, 4(2), 27; doi:10.3390/hydrology4020027 -
Abstract
In this study, two hydrologic models, the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) and the Soil and Water Assessment Tool (SWAT), were applied to predict stream flow and suspended sediment concentration (SSC) in a small agricultural watershed in Ishigaki Island, Japan, in which
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In this study, two hydrologic models, the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) and the Soil and Water Assessment Tool (SWAT), were applied to predict stream flow and suspended sediment concentration (SSC) in a small agricultural watershed in Ishigaki Island, Japan, in which the typical time scale of flood event was several hours. The performances of these two models were compared in order to select the right model for the study watershed. Both models were calibrated and validated against hourly stream flow and SSC for half-month periods of 15 to 31 May 2011 and 17 March to 7 April 2013, respectively. The results showed that both models successfully estimated hourly stream flow and SSC in a satisfactory way. For the short-term simulations, the GSSHA model performed slightly better in simulating stream flow as compared to SWAT during both calibration and validation periods. GSSHA only gave better accuracy when predicting SSC during calibration, while SWAT performed slightly better during validation. For long-term simulations, both models yielded comparable results for long-term stream flow and SSC with acceptable agreement. However, SWAT predicted the overall variation of long-term SSC better than GSSHA. Full article
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Open AccessArticle
Application of a Standardized Precipitation Index for Meteorological Drought Analysis of the Semi-Arid Climate Influence in Minas Gerais, Brazil
Hydrology 2017, 4(2), 26; doi:10.3390/hydrology4020026 -
Abstract
In recent years, the Southeast region in Brazil has suffered from the effects of drought events. Analyzing the history of drought events is fundamental to establish potential risks of the occurrence of droughts in the future. One of the many ways to prevent
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In recent years, the Southeast region in Brazil has suffered from the effects of drought events. Analyzing the history of drought events is fundamental to establish potential risks of the occurrence of droughts in the future. One of the many ways to prevent substantial impacts and evaluate a drought risk assessment is through analysis of severity, duration and frequency characteristics of these events. In this context, the current study developed Severity-Duration-Frequency curves and derived an isohyetal map for the area influenced by the semi-arid climate in the state of Minas Gerais, through the analysis of 17 rainfall stations. The drought events identification and the analysis of its conditions were assessed using the Standardized Precipitation Index (SPI) for a 12-month time scale. The SDF curves were developed using the minimum cumulative 12-month precipitation values fitted to the Gamma distribution for 1, 3, 6, 9 and 12-month drought durations. The computed SDF curves for each station were further regionalized in order to obtain a general result for the study area. It can be observed that for a return period of 100 years, the estimated cumulative 12-month precipitation varies from 353 mm in a 1-month drought duration to 458 mm in a 12-month drought duration. The derived isohyetal map provides a more accurate local application of the results. Full article
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Open AccessFeature PaperCase Report
Development of Flood Warning System and Flood Inundation Mapping Using Field Survey and LiDAR Data for the Grand River near the City of Painesville, Ohio
Hydrology 2017, 4(2), 24; doi:10.3390/hydrology4020024 -
Abstract
Abstract: Flooding is one of the most frequent natural disasters across the world, which damages properties and may take the lives of people. Flood warning systems can play a significant role in minimizing those effects by helping to evacuate people from the
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Abstract: Flooding is one of the most frequent natural disasters across the world, which damages properties and may take the lives of people. Flood warning systems can play a significant role in minimizing those effects by helping to evacuate people from the probable affected areas during peak flash flood times. Therefore, a conceptual approach of an automated flood warning system is presented in this research to protect several houses, roads, and infrastructures along the Grand River, which are vulnerable to flooding during a 500 year return period flash flood. The Grand River is a tributary of Lake Erie, which lies in the Grand River watershed in the northeastern region of the United States and has a humid continental climate and receives lake-effect precipitation. The flood warning system for the Grand River was developed specifically during high flow conditions by calculating flood travel time and generating the inundation mapping for 12 different selected flood stages, which were approximately 2 to 500 years in recurrence interval, ranging from 10 ft. to 21 ft. at gage station 04212100, near the City of Painesville, OH. A Hydraulic Engineering Center-River Analysis System (HEC-RAS) was utilized for hydraulic modeling. Geospatial data required for HEC-RAS was obtained using a Digital Elevation Model (DEM) derived from Light Detection and Ranging (LiDAR) datasets, which were pre-processed and post-processed in HEC-GeoRAS to produce flood inundation maps. The flood travel time and flood inundation maps were generated by integrating LiDAR data with field verified survey results in order to provide the evacuation lead time needed for the people of probable affected areas, which is different from earlier studies. The generated inundation maps estimate the aerial extent of flooding along the Grand River corresponding to the various flood stages at the gage station near the City of Painesville and Harpersfield. The inundation maps were overlaid on digital orthographic maps to visualize its aerial extents, which can be uploaded online to provide a real-time inundation warning to the public when the flood occurs in the river. Full article
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