Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Water, Volume 10, Issue 6 (June 2018)

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Cover Story (view full-size image) Agricultural intensification has the undesirable effect of degrading water quality. Water quality [...] Read more.
View options order results:
result details:
Displaying articles 1-148
Export citation of selected articles as:
Open AccessReview Reuse and Recycling of Livestock and Municipal Wastewater in Chilean Agriculture: A Preliminary Assessment
Water 2018, 10(6), 817; https://doi.org/10.3390/w10060817
Received: 17 May 2018 / Revised: 11 June 2018 / Accepted: 14 June 2018 / Published: 20 June 2018
PDF Full-text (3782 KB) | HTML Full-text | XML Full-text
Abstract
Chile is an agricultural power, but also one of the most vulnerable countries to climate change and water shortage. About 50% of the irrigated agriculture land in Chile is in the central zone, thanks to its agricultural-climatic characteristics that provide an adequate water
[...] Read more.
Chile is an agricultural power, but also one of the most vulnerable countries to climate change and water shortage. About 50% of the irrigated agriculture land in Chile is in the central zone, thanks to its agricultural-climatic characteristics that provide an adequate water supply (100–4000 m3/s). However, the vulnerability scenario in this zone is high due to the seasonal availability of water resources. Therefore, opportunities to use non-conventional alternative sources (e.g., wastewater) become an appealing and feasible option due to the high population and animal density (>76%) in this part of the country. Moreover, the physicochemical characteristics of the municipal and livestock wastewater suggest that there are potential opportunities to recycle nutrients for agricultural production. In Chile, wastewater reuse opportunities are noted by the wide coverage of wastewater treatment programs, with municipal and intensified livestock production taking up most of the percentage (>99%). Nevertheless, more than 70% of wastewater treatment systems reach biological secondary treatment, which suggests reuse possibilities only for non-food crops. Therefore, this paper is focused on a preliminary analysis of the potential of reusing and recycling municipal and livestock wastewater for Chilean agriculture. There is some reuse work occurring in Chile, specifically in the use of municipal and livestock wastewater for cereal crops (animal feed), forests, and grasslands. However, aspects related to the long-term effects of these practices have not yet been evaluated. Therefore, municipal and livestock wastewater in Chile could be re-valued in agriculture, but the current quality and condition of treated wastewater do not ensure its safe use in food crops. In addition, state policies are needed to provide sustainability (circular and ethic economy) to water reusing/recycling in agriculture. Full article
(This article belongs to the Section Water and Wastewater Treatment)
Figures

Figure 1

Open AccessFeature PaperArticle Phosphorus Fluxes from Three Coastal Watersheds under Varied Agriculture Intensities to the Northern Gulf of Mexico
Water 2018, 10(6), 816; https://doi.org/10.3390/w10060816
Received: 21 May 2018 / Revised: 3 June 2018 / Accepted: 16 June 2018 / Published: 20 June 2018
PDF Full-text (5140 KB) | HTML Full-text | XML Full-text
Abstract
This study aims to evaluate recent total phosphorus (TP) and dissolved inorganic phosphorus (DIP) transport from three coastal rivers—the Calcasieu, Mermentau, and Vermilion Rivers—that drain watersheds with varied agriculture intensities (21%, 67%, and 61%, respectively) into the northern Gulf of Mexico, one of
[...] Read more.
This study aims to evaluate recent total phosphorus (TP) and dissolved inorganic phosphorus (DIP) transport from three coastal rivers—the Calcasieu, Mermentau, and Vermilion Rivers—that drain watersheds with varied agriculture intensities (21%, 67%, and 61%, respectively) into the northern Gulf of Mexico, one of the world’s largest summer hypoxic zones. The study also examined the spatial trends of TP and DIP from freshwater to saltwater along an 88-km estuarine reach with salinity increasing from 0.02 to 29.50. The results showed that from 1990–2009 to 2010–2017, the TP fluxes for one of the agriculture-intensive rivers increased while no significant change was found for the other two rivers. Change in river discharge was the main reason for this TP flux trend. The two more agriculture-intensive river basins showed consistently higher TP and DIP concentrations and fluxes, as well as higher DIP:TP ratios than the river draining less agriculture-intensive land, confirming the strong effect of land uses on phosphorus input and speciation. Longitudinal profiles of DIP along the salinity gradient of the estuarine reach displayed characteristic input behavior. Desorption of DIP from suspended solids and river bed sediments, urban inputs, as well as stronger calcium carbonate and phosphorus co-precipitation at the marine endmember could be the reasons for such mixing dynamics. Full article
(This article belongs to the Special Issue Recent Progress in River Biogeochemistry Research)
Figures

Figure 1

Open AccessTechnical Note Parameter Estimation for Soil Water Retention Curve Using the Salp Swarm Algorithm
Water 2018, 10(6), 815; https://doi.org/10.3390/w10060815
Received: 17 May 2018 / Revised: 15 June 2018 / Accepted: 18 June 2018 / Published: 20 June 2018
PDF Full-text (522 KB) | HTML Full-text | XML Full-text
Abstract
This paper employs an optimization algorithm called the salp swarm algorithm (SSA) for the parameter estimation of the soil water retention curve model. The SSA simulates the behavior of searching for food of the salp swarm and manages to find the optimal solutions
[...] Read more.
This paper employs an optimization algorithm called the salp swarm algorithm (SSA) for the parameter estimation of the soil water retention curve model. The SSA simulates the behavior of searching for food of the salp swarm and manages to find the optimal solutions for optimization problems. In this paper, parameter estimation of the van Genuchten model based on nine soil samples, covering eight soil textures, is conducted. The optimization problem that minimizes the difference between the measured and the estimated water content is formulated, and the SSA is applied to solve this problem. To validate the competitive advantage of the SSA, the experimental results are compared with Particle Swarm Optimization algorithm, the Differential Evolution algorithm and the RETC program, which indicates that SSA performs better than the three methods. Full article
(This article belongs to the Special Issue Data-Driven Methods for Agricultural Water Management)
Figures

Figure 1

Open AccessArticle The Impacts of Climate Variability and Land Use Change on Streamflow in the Hailiutu River Basin
Water 2018, 10(6), 814; https://doi.org/10.3390/w10060814
Received: 6 March 2018 / Revised: 16 June 2018 / Accepted: 17 June 2018 / Published: 20 June 2018
PDF Full-text (10512 KB) | HTML Full-text | XML Full-text
Abstract
The Hailiutu River basin is a typical semi-arid wind sandy grass shoal watershed in northwest China. Climate and land use have changed significantly during the period 1970–2014. These changes are expected to impact hydrological processes in the basin. The Mann–Kendall (MK) test and
[...] Read more.
The Hailiutu River basin is a typical semi-arid wind sandy grass shoal watershed in northwest China. Climate and land use have changed significantly during the period 1970–2014. These changes are expected to impact hydrological processes in the basin. The Mann–Kendall (MK) test and sequential t-test analysis of the regime shift method were used to detect the trend and shifts of the hydrometeorological time series. Based on the analyzed results, seven scenarios were developed by combining different land use and/or climate situations. The Soil Water Assessment Tool (SWAT) model was applied to analyze the impacts of climate variability and land use change on the values of the hydrological components. The China Meteorological Assimilation Driving Datasets for the SWAT model (CMADS) was applied to enhance the spatial expressiveness of precipitation data in the study area during the period 2008–2014. Rather than solely using observed precipitation or CMADS precipitation, the precipitation values of CMADS and the observed precipitation values were combined to drive the SWAT model for better simulation results. From the trend analysis, the annual streamflow and wind speed showed a significant downward trend. No significant trend was found for the annual precipitation series; however, the temperature series showed upward trends. With the change point analysis, the whole study period was divided into three sub-periods (1970–1985, 1986–2000, and 2001–2014). The annual precipitation, mean wind speed, and average temperature values were 316 mm, 2.62 m/s, and 7.9 °C, respectively, for the sub-period 1970–1985, 272 mm, 2.58 m/s, and 8.4 °C, respectively, for the sub-period 1986–2000, and 391 mm, 2.2 m/s, and 9.35 °C, respectively, for the sub-period 2001–2014. The simulated mean annual streamflow was 35.09 mm/year during the period 1970–1985. Considering the impact of the climate variability, the simulated mean annual streamflow values were 32.94 mm/year (1986–2000) and 36.78 mm/year (2001–2014). Compared to the period 1970–1985, the simulated mean annual streamflow reduced by 2.15 mm/year for the period 1986–2000 and increased by 1.69 mm/year for the period 2001–2014. The main variations of land use from 1970 to 2014 were the increased area of shrub and grass land and decreased area of sandy land. In the simulation it was shown that these changes caused the mean annual streamflow to decrease by 0.23 mm/year and 0.68 mm/year during the periods 1986–2000 and 2001–2014, respectively. Thus, the impact of climate variability on the streamflow was more profound than that of land use change. Under the impact of coupled climate variability and land use change, the mean annual streamflow decreased by 2.45 mm/year during the period 1986–2000, and the contribution of this variation to the decrease in observed streamflow was 27.8%. For the period 2001–2014, the combined climate variability and land use change resulted in an increase of 0.84 mm/year in annual streamflow. The results obtained in this study could provide guidance for water resource management and planning in the Erdos plateau. Full article
Figures

Figure 1

Open AccessArticle Extrapolation of Leaf Measurements to Obtain the Whole-Canopy Transpiration of C3 and C4 Xerophytic Shrubs
Water 2018, 10(6), 813; https://doi.org/10.3390/w10060813
Received: 9 May 2018 / Revised: 4 June 2018 / Accepted: 7 June 2018 / Published: 20 June 2018
PDF Full-text (1380 KB) | HTML Full-text | XML Full-text
Abstract
Quantifying the water balance within areas with sparse vegetation requires frequent measurement of transpiration in water-limited, arid, desert ecosystems. Field experiments were conducted in Shapotou, northwestern China, to examine the feasibility of up-scaling the transpiration of C3 and C4 xerophytic shrubs
[...] Read more.
Quantifying the water balance within areas with sparse vegetation requires frequent measurement of transpiration in water-limited, arid, desert ecosystems. Field experiments were conducted in Shapotou, northwestern China, to examine the feasibility of up-scaling the transpiration of C3 and C4 xerophytic shrubs (Reaumuria soongorica and Salsola passerina, respectively) from the leaf to the canopy level throughout the growing season in 2015. The large weighing lysimeter method and LI-6400XT portable photosynthesis system were used to make relatively long-term measurements of transpiration. The results indicated that meteorological factors coupled with stomatal conductance affected the transpiration rate of the two shrubs at the leaf level, and that the vapor pressure deficit other than net radiation and the air temperature affected the transpiration rate of S. passerina at the canopy level. Precipitation and vegetation characteristics determined the transpiration amount of the C3 and C4 xerophytic shrubs. The leaf gas exchange measurements were arithmetically scaled up to the canopy level based on the leaf area. The validity of the extrapolation was evaluated by comparing the upscale values of transpiration with the calculated values obtained from lysimeter measurement. The up-scaling approach accurately (±0.005 mm h−1, RMSE = 35%) obtained canopy transpiration from the leaf measurements. Our study suggests that the up-scaling method based on leaf area can be adopted to determine the canopy transpiration of C3 and C4 xerophytic shrubs in arid desert environments. Full article
(This article belongs to the Section Hydrology)
Figures

Figure 1

Open AccessArticle An Improved Approach for Evapotranspiration Estimation Using Water Balance Equation: Case Study of Yangtze River Basin
Water 2018, 10(6), 812; https://doi.org/10.3390/w10060812
Received: 24 May 2018 / Revised: 7 June 2018 / Accepted: 16 June 2018 / Published: 19 June 2018
PDF Full-text (6621 KB) | HTML Full-text | XML Full-text
Abstract
Evapotranspiration (ET) is a critical component of the water cycle, and it plays an important role in global water exchange and energy flow. However, accurate estimation and numerical simulation of regional ET remain difficult. In this work, based on the water balance equation,
[...] Read more.
Evapotranspiration (ET) is a critical component of the water cycle, and it plays an important role in global water exchange and energy flow. However, accurate estimation and numerical simulation of regional ET remain difficult. In this work, based on the water balance equation, an improved regional ET estimating approach was developed by using Gravity Recovery and Climate Experiment (GRACE), daily precipitation, and discharge data. Firstly, the method and algorithm were validated by simulation study. Compared with ET estimated from previous methods, the result derived from our method present significant improvement, with the correlation coefficient great than 0.9. Secondly, using our improved method, the spatially averaged ET over the Yangtze River Basin (YRB) was computed for the period 2003–2013. The ET estimations were in good consistency with different ET products, and the mean annual value of ET estimation over the YRB was close to the difference between precipitation and discharge over the YRB. Thirdly, the comparison between ET estimation and independent estimates of meteorological factors and soil moisture over the entire YRB were conducted through the entire YRB. The analysis indicated that near-surface temperature, as responsive to atmospheric demand, was the limiting factor of time variation of ET, with the correlation coefficients of 0.69. We also analyzed the relationship between the mean annual ET and atmospheric demand for seven subcatchments of the YRB, which indicated that the spatial distribution characteristics of ET estimated by our method were in accord with atmospheric conditions. These results indicated the good performance of our improved approach in estimating ET variations over the YRB. It also demonstrates the applicability of GRACE to the analysis of hydrological features such as regional ET. Full article
(This article belongs to the Section Hydrology)
Figures

Figure 1

Open AccessArticle Simulation of Fluid and Complex Obstacle Coupling Based on Narrow Band FLIP Method
Water 2018, 10(6), 811; https://doi.org/10.3390/w10060811
Received: 1 May 2018 / Revised: 8 June 2018 / Accepted: 11 June 2018 / Published: 19 June 2018
PDF Full-text (8775 KB) | HTML Full-text | XML Full-text
Abstract
With the continuous development of fluid simulation theory and technology, there are increasingly higher requirements for simulation of complex fluid interaction. Fluid simulation based on the Eulerian method is limited by the grid resolution, and the sawtooth phenomenon occurs near the obstacle boundary.
[...] Read more.
With the continuous development of fluid simulation theory and technology, there are increasingly higher requirements for simulation of complex fluid interaction. Fluid simulation based on the Eulerian method is limited by the grid resolution, and the sawtooth phenomenon occurs near the obstacle boundary. To enhance the fluid interaction performance with complex obstacle, an advanced fluid interaction method was proposed based on NBFLIP. Improved from FLIP method, the NBFLIP method combines the advantages of Euler method and Lagrangian method. The SDF method is proposed in complex obstacle discretion, with an expectation to facilitate the processing with obstacle boundary and efficiency improvement. Compared with FLIP method, particle number in NBFLIP method is reduced by 86.2% and the average running time per frame is reduced by 36.1%. Full article
(This article belongs to the Section Hydraulics)
Figures

Figure 1

Open AccessArticle End Use Level Water and Energy Interactions: A Large Non-Residential Building Case Study
Water 2018, 10(6), 810; https://doi.org/10.3390/w10060810
Received: 11 May 2018 / Revised: 13 June 2018 / Accepted: 15 June 2018 / Published: 19 June 2018
PDF Full-text (2641 KB) | HTML Full-text | XML Full-text
Abstract
Within the European Union, buildings account for around 40% of the energy use and 36% of CO2 emissions, thus representing a significant challenge in the context of recent EU directives that require all new buildings to be nearly zero-energy by 2020. Reduced
[...] Read more.
Within the European Union, buildings account for around 40% of the energy use and 36% of CO2 emissions, thus representing a significant challenge in the context of recent EU directives that require all new buildings to be nearly zero-energy by 2020. Reduced consumption of water, and hot water in particular, provides a significant opportunity to reduce energy consumption. While there have been numerous studies pertaining to the water-energy nexus of residential buildings, the complexity of water networks in larger buildings has meant that this area has been relatively unexplored. The paper presents a comprehensive investigation of the hot water use profile, associated energy use, on-site pumping energy use, carbon emissions, and solar energy harvesting potential in an Irish university building over periods before and after water conservation efforts. Total water-related energy consumption (including the heating and pumping losses) were analysed using the WHAM model and modified pumping energy expressions. The results revealed that water heating including losses contributed to as high as 30% of total building energy consumption, and stringent water conservation measures reduced the average hot water use rate by 8.5 m3/day. It was found that 10% of the total pumping energy was constituted by pump start-ups. Simulation results for solar harvesting potential in the study site found that around 60% of water heating energy demand could be met by solar energy in the new water demand scenario. The study results can act as a benchmark for similar buildings, and the model combination can be emulated in future studies. Full article
(This article belongs to the Special Issue Carbon Footprint of Water Supply and Wastewater Treatment)
Figures

Graphical abstract

Open AccessArticle Multi-Source Uncertainty Analysis in Simulating Floodplain Inundation under Climate Change
Water 2018, 10(6), 809; https://doi.org/10.3390/w10060809
Received: 30 May 2018 / Revised: 14 June 2018 / Accepted: 15 June 2018 / Published: 19 June 2018
PDF Full-text (8048 KB) | HTML Full-text | XML Full-text
Abstract
Floodplains are highly complex and dynamic systems in terms of their hydrology. Thus, they harbor highly specialized floodplain plant species depending on different inundation characteristics. Climate change will most likely alter those characteristics. This study investigates the potential impact of climate change on
[...] Read more.
Floodplains are highly complex and dynamic systems in terms of their hydrology. Thus, they harbor highly specialized floodplain plant species depending on different inundation characteristics. Climate change will most likely alter those characteristics. This study investigates the potential impact of climate change on the inundation characteristics of a floodplain of the Rhine River in Hesse, Germany. We report on the cascading uncertainty introduced through climate projections, climate model structure, and parameter uncertainty. The established modeling framework integrates projections of two general circulation models (GCMs), three emission scenarios, a rainfall–runoff model, and a coupled surface water–groundwater model. Our results indicate large spatial and quantitative uncertainties in the simulated inundation characteristics, which are mainly attributed to the GCMs. Overall, a shift in the inundation pattern, possible in both directions, and an increase in inundation extent are simulated. This can cause significant changes in the habitats of species adapted to these highly-endangered ecosystems. Full article
(This article belongs to the Section Hydrology)
Figures

Figure 1

Open AccessArticle Research on Cascade Reservoirs’ Short-Term Optimal Operation under the Effect of Reverse Regulation
Water 2018, 10(6), 808; https://doi.org/10.3390/w10060808
Received: 7 May 2018 / Revised: 2 June 2018 / Accepted: 4 June 2018 / Published: 19 June 2018
PDF Full-text (3122 KB) | HTML Full-text | XML Full-text
Abstract
Currently research on joint operation of a large reservoir and its re-regulating reservoir focuses on either water quantity regulation or water head regulation. The accuracy of relevant models is in need of improvement if the influence of factors such as water flow hysteresis
[...] Read more.
Currently research on joint operation of a large reservoir and its re-regulating reservoir focuses on either water quantity regulation or water head regulation. The accuracy of relevant models is in need of improvement if the influence of factors such as water flow hysteresis and the aftereffect of tail water level variation are taken into consideration. In this paper, given the actual production of Pankou-Xiaoxuan cascade hydropower stations that combines two operation modes (‘electricity to water’ and ‘water to electricity’), a coupling model of their short-term optimal operation is developed, which considers Xiaoxuan reservoir’s regulating effect on Pankou reservoir’s outflow volume and water head. Factors such as water flow hysteresis and the aftereffect of tail water level variation are also considered to enhance the model’s accuracy. The Backward Propagation (BP) neural network is employed for precise calculation of the downstream reservoir’s inflow and the upstream reservoir’s tail water level. Besides, we put forth Accompanying Progressive Optimality Algorithm (APOA) to solve the coupling model with aftereffect. An example is given to verify the scientificity of the proposed model and the advantages of APOA. Through analysis of the model calculation results, the optimal operation rules of the cascade reservoirs are obtained in terms of water quantity regulation and water head regulation, which can provide scientific reference for cascade reservoirs’ optimal operation. Full article
(This article belongs to the Special Issue Adaptive Catchment Management and Reservoir Operation)
Figures

Figure 1

Open AccessArticle Improving the Muskingum Flood Routing Method Using a Hybrid of Particle Swarm Optimization and Bat Algorithm
Water 2018, 10(6), 807; https://doi.org/10.3390/w10060807
Received: 21 May 2018 / Revised: 12 June 2018 / Accepted: 15 June 2018 / Published: 19 June 2018
PDF Full-text (2168 KB) | HTML Full-text | XML Full-text
Abstract
Flood prediction and control are among the major tools for decision makers and water resources planners to avoid flood disasters. The Muskingum model is one of the most widely used methods for flood routing prediction. The Muskingum model contains four parameters that must
[...] Read more.
Flood prediction and control are among the major tools for decision makers and water resources planners to avoid flood disasters. The Muskingum model is one of the most widely used methods for flood routing prediction. The Muskingum model contains four parameters that must be determined for accurate flood routing. In this context, an optimization process that self-searches for the optimal values of these four parameters might improve the traditional Muskingum model. In this study, a hybrid of the bat algorithm (BA) and the particle swarm optimization (PSO) algorithm, i.e., the hybrid bat-swarm algorithm (HBSA), was developed for the optimal determination of these four parameters. Data for the three different case studies from the USA and the UK were utilized to examine the suitability of the proposed HBSA for flood routing. Comparative analyses based on the sum of squared deviations (SSD), sum of absolute deviations (SAD), error of peak discharge, and error of time to peak showed that the proposed HBSA based on the Muskingum model achieved excellent flood routing accuracy compared to that of other methods while requiring less computational time. Full article
(This article belongs to the Special Issue Flood Forecasting Using Machine Learning Methods)
Figures

Figure 1

Open AccessArticle Water Quality Prediction Model of a Water Diversion Project Based on the Improved Artificial Bee Colony–Backpropagation Neural Network
Water 2018, 10(6), 806; https://doi.org/10.3390/w10060806
Received: 1 May 2018 / Revised: 15 June 2018 / Accepted: 16 June 2018 / Published: 18 June 2018
PDF Full-text (5551 KB) | HTML Full-text | XML Full-text
Abstract
Prediction of water quality which can ensure the water supply and prevent water pollution is essential for a successful water transfer project. In recent years, with the development of artificial intelligence, the backpropagation (BP) neural network has been increasingly applied for the prediction
[...] Read more.
Prediction of water quality which can ensure the water supply and prevent water pollution is essential for a successful water transfer project. In recent years, with the development of artificial intelligence, the backpropagation (BP) neural network has been increasingly applied for the prediction and forecasting field. However, the BP neural network frame cannot satisfy the demand of higher accuracy. In this study, we extracted monitoring data from the water transfer channel of both the water resource and the intake area as training samples and selected some distinct indices as input factors to establish a BP neural network whose connection weight values between network layers and the threshold of each layer had already been optimized by an improved artificial bee colony (IABC) algorithm. Compared with the traditional BP and ABC-BP neural network model, it was shown that the IABC-BP neural network has a greater ability for forecasting and could achieve much better accuracy, nearly 25% more precise than the BP neural network. The new model is particularly practical for the water quality prediction of a water diversion project and could be readily applied in this field. Full article
(This article belongs to the Special Issue Water Quality: A Component of the Water-Energy-Food Nexus)
Figures

Figure 1

Open AccessArticle Presence of Antibiotic-Resistant Escherichia coli in Wastewater Treatment Plant Effluents Utilized as Water Reuse for Irrigation
Water 2018, 10(6), 805; https://doi.org/10.3390/w10060805
Received: 20 May 2018 / Revised: 8 June 2018 / Accepted: 15 June 2018 / Published: 18 June 2018
PDF Full-text (1162 KB) | HTML Full-text | XML Full-text
Abstract
Providing safe water through water reuse is becoming a global necessity. One concern with water reuse is the introduction of unregulated contaminants to the environment that cannot be easily removed by conventional wastewater treatment plants (WWTP). The occurrence of ampicillin, sulfamethoxazole, ciprofloxacin, and
[...] Read more.
Providing safe water through water reuse is becoming a global necessity. One concern with water reuse is the introduction of unregulated contaminants to the environment that cannot be easily removed by conventional wastewater treatment plants (WWTP). The occurrence of ampicillin, sulfamethoxazole, ciprofloxacin, and tetracycline-resistant Escherichia coli through the treatment stages of a WWTP (raw sewage, post-secondary, post-UV and post-chlorination) was investigated from January to May 2016. The highest concentrations of antibiotic resistant E. coli in the effluent were detected in April after rainfall. Ampicillin-resistant E. coli was the most common at the post UV and chlorination stages comprising 63% of the total E. coli population. The minimum inhibitory concentration (MIC) analysis showed that one in five isolates was resistant to three or more antibiotics, and the majority of these E. coli were resistant to ampicillin, followed by sulfamethoxazole and ciprofloxacin. The highest MIC was detected at the finished water after application of multiple disinfection methods. Tetracycline resistance was the least observed among others, indicating that certain drug families may respond to wastewater treatment differently. Currently, there are no policies to enforce the monitoring of antibiotic-resistant pathogen removal in WWTP. Better guidelines are needed to better regulate reuse water and prevent health risk upon exposure to antibiotic-resistant bacteria. Full article
(This article belongs to the Special Issue Antimicrobial Resistance in Environmental Waters)
Figures

Figure 1

Open AccessFeature PaperArticle Delineation of Suitable Zones for the Application of Managed Aquifer Recharge (MAR) in Coastal Aquifers Using Quantitative Parameters and the Analytical Hierarchy Process
Water 2018, 10(6), 804; https://doi.org/10.3390/w10060804
Received: 18 April 2018 / Revised: 6 June 2018 / Accepted: 15 June 2018 / Published: 18 June 2018
PDF Full-text (29622 KB) | HTML Full-text | XML Full-text
Abstract
Coastal aquifer salinization is usually related to groundwater overexploitation and water table decline. Managed Aquifer Recharge (MAR) can be applied as a measure to reverse and prevent this phenomenon. A detailed literature review was performed to identify the various methods and parameters commonly
[...] Read more.
Coastal aquifer salinization is usually related to groundwater overexploitation and water table decline. Managed Aquifer Recharge (MAR) can be applied as a measure to reverse and prevent this phenomenon. A detailed literature review was performed to identify the various methods and parameters commonly used to determine suitable sites of MAR application. Based on the review results, a new multi-criteria index (SuSAM) that is compatible to coastal aquifers was developed to delineate suitable zones for MAR application. New parameters were introduced into the index, such as distance from the shore and hydraulic resistance of the vadose zone, while factor weights were determined using the Analytical Hierarchy Process (AHP) and single sensitivity analysis. The applicability of the new index was examined in the coastal aquifer of the Anthemountas basin located in northern Greece. The most suitable areas for MAR application cover 28% of the aquifer’s surface area, while 16% of the area was characterized as non-suitable for MAR application. The new method constitutes the first step of the managed aquifer recharge concept for the delineation of MAR-suitable zones in coastal aquifers. Full article
(This article belongs to the Special Issue Salinization of Coastal Aquifer Systems)
Figures

Graphical abstract

Open AccessArticle Modeling the Spatial and Seasonal Variations of Groundwater Head in an Urbanized Area under Low Impact Development
Water 2018, 10(6), 803; https://doi.org/10.3390/w10060803
Received: 9 May 2018 / Revised: 7 June 2018 / Accepted: 15 June 2018 / Published: 17 June 2018
PDF Full-text (4914 KB) | HTML Full-text | XML Full-text
Abstract
Increasing impervious land cover has great impacts on groundwater regimes in urbanized areas. Low impact development (LID) is generally regarded as a sustainable solution for groundwater conservation. However, the effects of LID on the spatial-temporal distribution of groundwater are not yet fully understood.
[...] Read more.
Increasing impervious land cover has great impacts on groundwater regimes in urbanized areas. Low impact development (LID) is generally regarded as a sustainable solution for groundwater conservation. However, the effects of LID on the spatial-temporal distribution of groundwater are not yet fully understood. In this case study, a coupled Storm Water Management Model (SWMM) and Finite Element Subsurface FLOW system (FEFLOW) model was used to simulate surface and groundwater flow in an urbanized area in Shenzhen, China. After verification, the model was used to analyze the spatial-seasonal variations of groundwater head and hydrological processes under different LID scenarios. The results indicate that if the runoff from 7.5% and 15% of impervious area is treated by LID facilities, the annual surface runoff decreases by 5% and 9%, respectively, and the spatial average groundwater head relative to sea level pressure increases by 0.9 m and 1.7 m in the study area, respectively. The rise in groundwater head generally decreases from the recharge zones to the discharge zones surrounded by the streams and coastal waters. However, the groundwater head change is determined not only by the location in the catchment, but also by the hydraulic conductivity of underlying aquifer and LID infiltration intensity. Moreover, LID significantly enhances groundwater recharge and aquifer storage in the wet seasons; in turn it increases aquifer release and groundwater discharge in the dry seasons. However, LID has the potential to increase the risk of groundwater flooding during wet seasons in areas with poor aquifer drainage capacity and shallow groundwater depth. The findings from this study provide the basis for further assessing the benefit and risk of LID infiltration for groundwater supplementation in the urbanized areas. Full article
(This article belongs to the Section Urban Water Management)
Figures

Figure 1

Back to Top