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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.

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18 pages, 1432 KiB  
Review
Porous Biochar Materials for Sustainable Water Treatment: Synthesis, Modification, and Application
by Ruichenzhi Li, Yujiao Wu, Xujun Lou, Haorui Li, Jing Cheng, Bin Shen and Lei Qin
Water 2023, 15(3), 395; https://doi.org/10.3390/w15030395 - 18 Jan 2023
Cited by 29 | Viewed by 10017
Abstract
In the current world, the increasingly developed industries of mankind have caused huge pollution to the earth on which we live. And the water resources, which are the source of human life, are also being seriously polluted and destroyed. Water pollution has become [...] Read more.
In the current world, the increasingly developed industries of mankind have caused huge pollution to the earth on which we live. And the water resources, which are the source of human life, are also being seriously polluted and destroyed. Water pollution has become an urgent need to deal with in today’s world. In order to achieve sustainable development, people are constantly using new materials in the process of water treatment. Biochar material is one of them. In the thermochemical process, biomass produces a common by-product coke, which is also called biochar as a result of biomass decomposition. Due to the low price and large specific surface area which can reach over 1000 m2·g−1, it has many applications and advantages in catalysis, adsorption, fuel cell, soil improvement, etc., and has a wide range of application prospects. Therefore, effectively prepared and used biochar in water treatment has become a method to improve the efficiency and economic benefits of thermochemical processes. In this overview, we first introduced the preparation methods of different new types of biomass materials, we then classified and discussed the various modification strategies, and finally discussed the application potential of biochar material for wastewater treatment. Full article
(This article belongs to the Special Issue Advances in Wastewater Resourcezation)
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18 pages, 5152 KiB  
Article
Quantification of Evapotranspiration by Calculations and Measurements Using a Lysimeter
by Branislav Kandra, Andrej Tall, Milan Gomboš and Dana Pavelková
Water 2023, 15(2), 373; https://doi.org/10.3390/w15020373 - 16 Jan 2023
Cited by 11 | Viewed by 5767
Abstract
Evapotranspiration is one of the key elements of water balance in nature. It significantly influences the water supply in the unsaturated zone of a soil profile. The unsaturated zone is a water source for the biosphere. The aim of this study is to [...] Read more.
Evapotranspiration is one of the key elements of water balance in nature. It significantly influences the water supply in the unsaturated zone of a soil profile. The unsaturated zone is a water source for the biosphere. The aim of this study is to measure, calculate and analyze the course of actual evapotranspiration, precipitation and dew totals as well as the totals of water flows at the lower boundary of unsaturated zone and the change in water content in specified soil volume. The measurements are used for verifying the results of numerical simulation. The methods used in the study were chosen based on the hypothesis that dynamics of water supply changes in the unsaturated zone is the result of the interactions between atmosphere, soil and plant cover. The elements of water balance were quantified by the methods of water balance, lysimeter measurements and numerical simulation on the model HYDRUS-1D, version 4. The abovementioned parameters were quantified for the East Slovakian Lowland, with an hourly time step during the years 2017, 2018 and 2020. The measurements have shown that evapotranspiration exceeded precipitation during all monitored periods, specifically by 22% in 2017, by 14% in 2019, and by 10% in 2020. The deficit was compensated for by capillary inflow from the groundwater level and the water supply in the unsaturated zone. A verification by measurement has shown that numerical simulation is imprecise in relation to the quantification of water flows at the lower boundary of the unsaturated zone. This inaccuracy is manifested in the higher value of the actual evapotranspiration, which is on average exceeded by 11%. The performance of the mathematical model is assessed as satisfactory for the analysis of the soil water regime. Full article
(This article belongs to the Special Issue Advances in Sustainable Agriculture Progress under Climate Change)
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18 pages, 2445 KiB  
Review
Recent Advances in Bacterial Degradation of Hydrocarbons
by Emiliana Pandolfo, Anna Barra Caracciolo and Ludovica Rolando
Water 2023, 15(2), 375; https://doi.org/10.3390/w15020375 - 16 Jan 2023
Cited by 68 | Viewed by 20156
Abstract
Hydrocarbons occur in fossil fuels such as crude oil and consist mainly of hydrogen and carbon. Although they are natural chemicals, crude oil refining results in commercial products with new physico-chemical properties, which can increase their complexity and toxicity, and hamper their degradation. [...] Read more.
Hydrocarbons occur in fossil fuels such as crude oil and consist mainly of hydrogen and carbon. Although they are natural chemicals, crude oil refining results in commercial products with new physico-chemical properties, which can increase their complexity and toxicity, and hamper their degradation. The presence of biodiverse natural microbial communities is a prerequisite for an effective homeostatic response to the various hydrocarbons, that contaminate ecosystems. However, their removal depends on the compartment contaminated (water, sediment, soil), their molecular weight, and their toxicity not hampering microbial activity. This paper reports different bacterial species involved in the biodegradation of aliphatic and aromatic hydrocarbons. Hydrocarbon contamination is generally due to the co-presence of a mixture of these chemicals, and their removal from the environment cannot rely on only a single species but generally requires bacterial consortia. Versatile bacterial metabolism relies on specific genes encoding the key enzymes involved in the peripheral metabolic and central metabolic pathways for degrading aliphatic and polycyclic aromatic hydrocarbons. Although microbial metabolism can have the potential for natural attenuation of these contaminants, hydrocarbon bioremediation, through biostimulation (e.g., use of surfactants, plants, earthworms, and nanoparticles) and bioaugmentation, can be a valid tool for removing them from actually contaminated soil, freshwater, groundwater, and seawater. Full article
(This article belongs to the Section Soil and Water)
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17 pages, 4451 KiB  
Article
Research on the Uplift Pressure Prediction of Concrete Dams Based on the CNN-GRU Model
by Guowei Hua, Shijie Wang, Meng Xiao and Shaohua Hu
Water 2023, 15(2), 319; https://doi.org/10.3390/w15020319 - 12 Jan 2023
Cited by 22 | Viewed by 3964
Abstract
Dam safety is considerably affected by seepage, and uplift pressure is a key indicator of dam seepage. Thus, making accurate predictions of uplift pressure trends can improve dam hazard forecasting. In this study, a convolutional neural network, (CNN)-gated recurrent neural network, (GRU)-based uplift [...] Read more.
Dam safety is considerably affected by seepage, and uplift pressure is a key indicator of dam seepage. Thus, making accurate predictions of uplift pressure trends can improve dam hazard forecasting. In this study, a convolutional neural network, (CNN)-gated recurrent neural network, (GRU)-based uplift pressure prediction model was developed, which included the CNN model’s feature extractability and the GRU model’s learnability for time series correlation data. Then, the model performance was verified using a dam as an example. The results showed that the mean absolute errors (MAEs) of the CNN-GRU model were 0.1554, 0.0398, 0.2306, and 0.1827, and the root mean square errors (RMSEs) were 0.1903, 0.0548, 0.2916, and 0.2127. The prediction performance was better than that of the particle swarm optimization–back propagation (PSO-BP), artificial bee colony optimization–support vector machines (ABC-SVM), GRU, long short-term memory network (LSTM), and CNN-LSTM models. The method improves the utilization rate of dam safety monitoring results and has engineering utility for safe dam operations. Full article
(This article belongs to the Special Issue Safety Monitoring and Management of Reservoir and Dams)
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16 pages, 4273 KiB  
Article
Experimental Study of Geometric Shape and Size of Sill Effects on the Hydraulic Performance of Sluice Gates
by Rasoul Daneshfaraz, Reza Norouzi, Parisa Ebadzadeh, Silvia Di Francesco and John Patrick Abraham
Water 2023, 15(2), 314; https://doi.org/10.3390/w15020314 - 11 Jan 2023
Cited by 22 | Viewed by 3538
Abstract
The present research was conducted to investigate the effect of sill geometry and sill width on the discharge coefficient and hydraulic jump characteristics. For this purpose, sills with semi-cylindrical, cylindrical, pyramidal, and rectangular cube geometries with widths of 0.075, 0.10, 0.15, and 0.2 [...] Read more.
The present research was conducted to investigate the effect of sill geometry and sill width on the discharge coefficient and hydraulic jump characteristics. For this purpose, sills with semi-cylindrical, cylindrical, pyramidal, and rectangular cube geometries with widths of 0.075, 0.10, 0.15, and 0.2 m were installed under a sluice gate. Results showed that increasing the sill width increased the sluice gate discharge coefficient compared to the no-sill mode. The results of placing a sill with different geometric shapes under a sluice gate indicate that using a semi-cylindrical sill increases the discharge coefficient. The ranked order of other sills, from the largest to smallest discharge coefficient, is: cylindrical, pyramidal, and rectangular cubic sills, respectively. The results show that the use of a sill increases the energy dissipation. Examining sills of different widths indicates that with increasing width, the increase in velocity and consequent decrease in the depth of the hydraulic jump causes an increase in energy loss. When employing sills of maximum width (b = 0.20 m) for pyramidal, semi-cylindrical, cylindrical, and rectangular shapes, the energy loss increased by 125, 119, 116, and 125% in section A, respectively. The semi-cylindrical sill is most effective in increasing the discharge coefficient, while the pyramidal sill is most effective for increasing energy dissipation. Full article
(This article belongs to the Section Hydraulics and Hydrodynamics)
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16 pages, 1715 KiB  
Article
Zeolite Adsorbents for Selective Removal of Co(II) and Li(I) from Aqueous Solutions
by Eduardo Díez, Cinthya Redondo, José María Gómez, Ruben Miranda and Araceli Rodríguez
Water 2023, 15(2), 270; https://doi.org/10.3390/w15020270 - 9 Jan 2023
Cited by 24 | Viewed by 7215
Abstract
Cobalt and lithium are critical metals because of its shortage, difficulty of extraction and huge economic impact due to their market value. The purpose of this work is to study their selective removal from aqueous solutions in different conditions using two commercial FAU [...] Read more.
Cobalt and lithium are critical metals because of its shortage, difficulty of extraction and huge economic impact due to their market value. The purpose of this work is to study their selective removal from aqueous solutions in different conditions using two commercial FAU zeolites as adsorbent materials. These solids were characterized by XRD, XRF and BET analysis, to follow up of their FAU structure integrity, their Si/Al ratio, and their specific surface area evolutions through their preparation process. The kinetic study indicates that using both zeolites with a dosage of 5 g/L a 100% cobalt removal from aqueous solutions is achievable, while lithium removal is kept around 30% (separation factor of 3.33). This selectivity is important as these two metals frequently appear together in leaching solutions form, for example, ion-Li batteries. In relation to the adsorption equilibrium, cobalt adsorption presents a finite adsorption capacity while this behavior is not observed in lithium adsorption. For this reason, Langmuir model is the most adequate to represent cobalt adsorption, while lithium adsorption is better represented by Freundlich model. Full article
(This article belongs to the Special Issue Adsorbents for Water and Wastewater Treatment and Resource Recovery, 2nd Edition)
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14 pages, 2517 KiB  
Article
Analysis of Water Resource Carrying Capacity and Obstacle Factors Based on GRA-TOPSIS Evaluation Method in Manas River Basin
by Anfuding Gulishengmu, Guang Yang, Lijun Tian, Yue Pan, Zhou Huang, Xingang Xu, Yongli Gao and Yi Li
Water 2023, 15(2), 236; https://doi.org/10.3390/w15020236 - 5 Jan 2023
Cited by 24 | Viewed by 2579
Abstract
The investigation of water resource carrying capacity (WRCC) in oasis cities in Northwest China is useful for guiding the sustainable development of arid regions. To quantify the WRCC of Shihezi, an oasis city in the Manas River Basin (MRB), Northwest China, a total [...] Read more.
The investigation of water resource carrying capacity (WRCC) in oasis cities in Northwest China is useful for guiding the sustainable development of arid regions. To quantify the WRCC of Shihezi, an oasis city in the Manas River Basin (MRB), Northwest China, a total of 21 indicators from three subsystems were selected to construct an evaluation index system based on the theory of the water resource–socio-economic–ecological complex system. Our study utilized a combination of the CRITIC method and the entropy weight method to determine the synthesis weight, the GRA-TOPSIS approach to comprehensively evaluate the WRCC, and the obstacle degree model to identify its main obstacle factors. Our results showed that the WRCC of Shihezi showed an increasing trend from 2011 to 2020, with the compositive index increasing from 0.3454 to 0.5210. The carrying capacities of the ecological environment and socio-economic subsystems were generally on the rise, but the rate of change was relatively gentle from 2017 to 2020. The carrying capacity index of the water resource subsystem dropped significantly from year to year from 2016 to 2020. The irrigation coverage rate, the proportion of agricultural water, water consumption per 10,000 CNY of GDP, the modulus of water production, water resource development and its utilization ratio, the water supply modulus, and the proportion of ecological water were the seven most significant obstacles. Our findings could serve as scientific references for enhancing WRCC and promoting the sustainable development of oasis cities in arid regions. Full article
(This article belongs to the Section Water Resources Management, Policy and Governance)
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28 pages, 2436 KiB  
Review
A Review of the Hydraulic Performance of Permeable Reactive Barriers Based on Granular Zero Valent Iron
by Stefania Bilardi, Paolo Salvatore Calabrò and Nicola Moraci
Water 2023, 15(1), 200; https://doi.org/10.3390/w15010200 - 3 Jan 2023
Cited by 21 | Viewed by 4497
Abstract
Permeable reactive barriers (PRBs) based on the use of zero valent iron (ZVI) represent an efficient technology for the remediation of contaminated groundwater, but the literature evidences “failures”, often linked to the difficulty of fully understanding the long-term performance of ZVI-based PRBs in [...] Read more.
Permeable reactive barriers (PRBs) based on the use of zero valent iron (ZVI) represent an efficient technology for the remediation of contaminated groundwater, but the literature evidences “failures”, often linked to the difficulty of fully understanding the long-term performance of ZVI-based PRBs in terms of their hydraulic behavior. The aim of this paper is to provide an overview of the long-term hydraulic behavior of PRBs composed of ZVI mixed with other reactive or inert materials. The literature on the hydraulic performance of ZVI-based PRBs in full-scale applications, on long-term laboratory testing and on related mathematical modeling was thoroughly analyzed. The outcomes of this review include an in-depth analysis of factors influencing the long-term behavior of ZVI-based PRBs (i.e., reactive medium, contamination and the geotechnical, geochemical and hydrogeological characteristics of the aquifer) and a critical revision of the laboratory procedures aimed at investigating their hydraulic performance. The analysis clearly shows that admixing ZVI with nonexpansive granular materials is the most suitable choice for obtaining a long-term hydraulically efficient PRB. Finally, the paper summarizes a procedure for the correct hydraulic design of ZVI-based PRBs and outlines that research should aim at developing numerical models able to couple PRBs’ hydraulic and reactive behaviors. Full article
(This article belongs to the Special Issue The Remediation of Groundwater Polluted by Metals)
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23 pages, 5152 KiB  
Article
Evaluation of Groundwater Quality for Irrigation in Deep Aquifers Using Multiple Graphical and Indexing Approaches Supported with Machine Learning Models and GIS Techniques, Souf Valley, Algeria
by Mohamed Hamdy Eid, Mohssen Elbagory, Ahmed A. Tamma, Mohamed Gad, Salah Elsayed, Hend Hussein, Farahat S. Moghanm, Alaa El-Dein Omara, Attila Kovács and Szűcs Péter
Water 2023, 15(1), 182; https://doi.org/10.3390/w15010182 - 2 Jan 2023
Cited by 80 | Viewed by 6657
Abstract
Irrigation has made a significant contribution to supporting the population’s expanding food demands, as well as promoting economic growth in irrigated regions. The current investigation was carried out in order to estimate the quality of the groundwater for agricultural viability in the Algerian [...] Read more.
Irrigation has made a significant contribution to supporting the population’s expanding food demands, as well as promoting economic growth in irrigated regions. The current investigation was carried out in order to estimate the quality of the groundwater for agricultural viability in the Algerian Desert using various water quality indices and geographic information systems (GIS). In addition, support vector machine regression (SVMR) was applied to forecast eight irrigation water quality indices (IWQIs), such as the irrigation water quality index (IWQI), sodium adsorption ratio (SAR), sodium percentage (Na%), soluble sodium percentage (SSP), potential salinity (PS), Kelly index (KI), permeability index (PI), potential salinity (PS), permeability index (PI), and residual sodium carbonate (RSC). Several physicochemical variables, such as temperature (T°), hydrogen ion concentration (pH), total dissolved solids (TDS), electrical conductivity (EC), K+, Na2+, Mg2+, Ca2+, Cl−, SO42−, HCO3−, CO32−, and NO3−, were measured from 45 deep groundwater wells. The hydrochemical facies of the groundwater resources were Ca–Mg–Cl/SO4 and Na–Cl−, which revealed evaporation, reverse ion exchange, and rock–water interaction processes. The IWQI, Na%, SAR, SSP, KI, PS, PI, and RSC showed mean values of 50.78, 43.07, 4.85, 41.78, 0.74, 29.60, 45.65, and −20.44, respectively. For instance, the IWQI for the obtained results indicated that the groundwater samples were categorized into high restriction to moderate restriction for irrigation purposes, which can only be used for plants that are highly salt tolerant. The SVMR model produced robust estimates for eight IWQIs in calibration (Cal.), with R2 values varying between 0.90 and 0.97. Furthermore, in validation (Val.), R2 values between 0.88 and 0.95 were achieved using the SVMR model, which produced reliable estimates for eight IWQIs. These findings support the feasibility of using IWQIs and SVMR models for the evaluation and management of the groundwater of complex terminal aquifers for irrigation. Finally, the combination of IWQIs, SVMR, and GIS was effective and an applicable technique for interpreting and forecasting the irrigation water quality used in both arid and semi-arid regions. Full article
(This article belongs to the Section Hydrogeology)
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18 pages, 2086 KiB  
Review
Real-Time Urban Flood Forecasting Systems for Southeast Asia—A Review of Present Modelling and Its Future Prospects
by Detchphol Chitwatkulsiri and Hitoshi Miyamoto
Water 2023, 15(1), 178; https://doi.org/10.3390/w15010178 - 1 Jan 2023
Cited by 25 | Viewed by 8675
Abstract
Many urban areas in tropical Southeast Asia, e.g., Bangkok in Thailand, have recently been experiencing unprecedentedly intense flash floods due to climate change. The rapid flood inundation has caused extremely severe damage to urban residents and social infrastructures. In addition, urban Southeast Asia [...] Read more.
Many urban areas in tropical Southeast Asia, e.g., Bangkok in Thailand, have recently been experiencing unprecedentedly intense flash floods due to climate change. The rapid flood inundation has caused extremely severe damage to urban residents and social infrastructures. In addition, urban Southeast Asia usually has inadequate capacities in drainage systems, complicated land use patterns, and a large vulnerable population in limited urban areas. To reduce the urban flood risk and enhance the resilience of vulnerable urban communities, it has been of essential importance to develop real-time urban flood forecasting systems for flood disaster prevention authorities and the urban public. This paper reviewed the state-of-the-art models of real-time forecasting systems for urban flash floods. The real-time system basically consists of the following subsystems, i.e., rainfall forecasting, drainage system modelling, and inundation area mapping. This paper summarized the recent radar data utilization methods for rainfall forecasting, physical-process-based hydraulic models for flood inundation prediction, and data-driven artificial intelligence (AI) models for the real-time forecasting system. This paper also dealt with available technologies for modelling, e.g., digital surface models (DSMs) for the finer urban terrain of drainage systems. The review indicated that an obstacle to using process-based hydraulic models was the limited computational resources and shorter lead time for real-time forecasting in many urban areas in tropical Southeast Asia. The review further discussed the prospects of data-driven AI models for real-time forecasting systems. Full article
(This article belongs to the Special Issue Urban Water-Related Problems)
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15 pages, 13938 KiB  
Article
Impact of Inorganic Solutes’ Release in Groundwater during Oil Shale In Situ Exploitation
by Qingyu Li, Laijun Lu, Quansheng Zhao and Shuya Hu
Water 2023, 15(1), 172; https://doi.org/10.3390/w15010172 - 31 Dec 2022
Cited by 46 | Viewed by 3435
Abstract
Oil shale can produce oil and shale gas by heating the oil shale at 300–500 °C. The high temperature and the release of organic matter can change the physical and mechanical properties of rocks and make the originally tight impervious layer become a [...] Read more.
Oil shale can produce oil and shale gas by heating the oil shale at 300–500 °C. The high temperature and the release of organic matter can change the physical and mechanical properties of rocks and make the originally tight impervious layer become a permeable layer under in situ exploitation conditions. To realize the potential impact of the in situ exploitation of oil shale on groundwater environments, a series of water–rock interaction experiments under different temperatures was conducted. The results show that, with the increase of the reaction temperature, the anions and cations in the aqueous solution of oil shale, oil shale–ash, and the surrounding rock show different trends, and the release of anions and cations in the oil shale–ash solution is most affected by the ambient temperature. The hydrochemical type of oil shale–ash solution is HCO3-SO4-Na-K at 80 °C and 100 °C, which changes the water quality. The main reasons are that (1) the high temperature (≥80 °C) can promote the dissolution of FeS in oil shale and (2) the porosity of oil shale increases after pyrolysis, making it easier to react with water. This paper is an important supplement to the research on the impact of the in situ exploitation of oil shale on the groundwater environment. Therefore, the impacts of in situ mining on groundwater inorganic minerals should be taken into consideration when evaluating in situ exploitation projects of oil shale. Full article
(This article belongs to the Special Issue Soil-Groundwater Pollution Investigations)
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19 pages, 853 KiB  
Review
Arsenic Occurrence and Cycling in the Aquatic Environment: A Comparison between Freshwater and Seawater
by Ningxin Wang, Zijun Ye, Liping Huang, Chushu Zhang, Yunxue Guo and Wei Zhang
Water 2023, 15(1), 147; https://doi.org/10.3390/w15010147 - 30 Dec 2022
Cited by 48 | Viewed by 11792
Abstract
Owing to the toxicity and adverse effects of arsenic on human health, its levels in aquatic environments are among the most serious threats to humans globally. To improve our understanding of its occurrence and cycling in aquatic environments, herein we review the concentration, [...] Read more.
Owing to the toxicity and adverse effects of arsenic on human health, its levels in aquatic environments are among the most serious threats to humans globally. To improve our understanding of its occurrence and cycling in aquatic environments, herein we review the concentration, speciation, and distribution of arsenic in freshwater, seawater, and sediments. Many natural processes, such as rock weathering and geothermal activities, contribute to the background arsenic concentrations in the natural environment, whereas metal mining and smelting are anthropogenic sources of arsenic in the water. The high solubility and mobility of arsenic in aquatic environments affects its global cycling. Furthermore, the biological processes in the aquatic environment are discussed, especially the possible microbe-mediated reactions of arsenic in sediments. In addition, various environmental factors, such as redox conditions, pH, and salinity, which influence the transformation of arsenic species, are summarized. Finally, the differences between freshwater and seawater with reference to the concentration as well as speciation and distribution patterns of arsenic are addressed. This review provides deep insights into arsenic occurrence and cycling between freshwater and seawater aquatic environments, which can more accurately distinguish the risks of arsenic in different water environments, and provides theoretical guidance for the prevention and control of arsenic risks. Full article
(This article belongs to the Section Water Quality and Contamination)
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34 pages, 6190 KiB  
Article
Assessment of Surface Water Quality Using the Water Quality Index (IWQ), Multivariate Statistical Analysis (MSA) and Geographic Information System (GIS) in Oued Laou Mediterranean Watershed, Morocco
by Hamza El Azhari, El Khalil Cherif, Otmane Sarti, El Mustapha Azzirgue, Houria Dakak, Hasna Yachou, Joaquim C. G. Esteves da Silva and Farida Salmoun
Water 2023, 15(1), 130; https://doi.org/10.3390/w15010130 - 29 Dec 2022
Cited by 43 | Viewed by 8159
Abstract
Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate [...] Read more.
Surface water is used for a variety of purposes, including agriculture, drinking water, and other services. Therefore, its quality is crucial for irrigation, human welfare, and health. Thus, the main objective is to improve surface water quality assessment and geochemical analysis to evaluate anthropogenic activities’ impact on surface water quality in the Oued Laou watershed, Northern Morocco. Thirteen surface water samples were characterized for 26 physicochemical and biological parameters. In this aspect, emerging techniques such as multivariate statistical approaches (MSA), water quality indices (WQI), irrigation water quality (IWQI), and Geographic Information System (GIS) were employed to identify the sources of surface water pollution, their suitability for consumption, and the distribution of surface water quality. The results showed that the major ion concentrations were reported in the following order: Ca2+, Na+, Mg2+, and K+; and HCO3− > CO32− > Cl− > SO42− > NO3− > F− > PO43− > NO2−. It was also demonstrated that almost all parameters had concentrations lower than World Health Organization (WHO) limits, except for bicarbonate ions (HCO3−) and the biochemical oxygen demand for five days (BOD5), which exceeded the WHO limits at 120 mg/L and 3 mg/L, respectively. Furthermore, the types of Ca2+-HCO3− (Calcium-Bicarbonate) and Ca2+-Mg2+-HCO3− (Calcium-Magnesium-Bicarbonate) predominated in surface water. The Principal Component Analysis (PCA) indicates that the Oued Laou river was exposed to two forms of contamination, the first being attributed to anthropogenic activities such as agriculture, while the second reflects the water-sediment interaction. The Hierarchical Cluster Analysis (HCA), reflecting the mineralization in the study area, has classified the samples into four clusters. The Inverse Distance Weighting (IDW) of the WQI indicates that 7.69% and 38.46% of the surface water represent, respectively, excellent and good quality for drinking. At the same time, the IWQI revealed that 92.30% of the water surface is good for irrigation. As a result, the combination of WQIs, PCA, IWQI, and GIS techniques is effective in providing clear information for assessing the suitability of surface water for drinking and its controlling factors and can also support decision-making in susceptible locations such as the Oued Laou river in northern Morocco. Full article
(This article belongs to the Section Water Quality and Contamination)
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23 pages, 11776 KiB  
Commentary
Assessing and Mitigating Ice-Jam Flood Hazards and Risks: A European Perspective
by Karl-Erich Lindenschmidt, Knut Alfredsen, Dirk Carstensen, Adam Choryński, David Gustafsson, Michał Halicki, Bernd Hentschel, Niina Karjalainen, Michael Kögel, Tomasz Kolerski, Marika Kornaś-Dynia, Michał Kubicki, Zbigniew W. Kundzewicz, Cornelia Lauschke, Albert Malinger, Włodzimierz Marszelewski, Fabian Möldner, Barbro Näslund-Landenmark, Tomasz Niedzielski, Antti Parjanne, Bogusław Pawłowski, Iwona Pińskwar, Joanna Remisz, Maik Renner, Michael Roers, Maksymilian Rybacki, Ewelina Szałkiewicz, Michał Szydłowski, Grzegorz Walusiak, Matylda Witek, Mateusz Zagata and Maciej Zdralewiczadd Show full author list remove Hide full author list
Water 2023, 15(1), 76; https://doi.org/10.3390/w15010076 - 26 Dec 2022
Cited by 16 | Viewed by 5202
Abstract
The assessment and mapping of riverine flood hazards and risks is recognized by many countries as an important tool for characterizing floods and developing flood management plans. Often, however, these management plans give attention primarily to open-water floods, with ice-jam floods being mostly [...] Read more.
The assessment and mapping of riverine flood hazards and risks is recognized by many countries as an important tool for characterizing floods and developing flood management plans. Often, however, these management plans give attention primarily to open-water floods, with ice-jam floods being mostly an afterthought once these plans have been drafted. In some Nordic regions, ice-jam floods can be more severe than open-water floods, with floodwater levels of ice-jam floods often exceeding levels of open-water floods for the same return periods. Hence, it is imperative that flooding due to river ice processes be considered in flood management plans. This also pertains to European member states who are required to submit renewed flood management plans every six years to the European governance authorities. On 19 and 20 October 2022, a workshop entitled “Assessing and mitigating ice-jam flood hazard and risk” was hosted in Poznań, Poland to explore the necessity of incorporating ice-jam flood hazard and risk assessments in the European Union’s Flood Directive. The presentations given at the workshop provided a good overview of flood risk assessments in Europe and how they may change due to the climate in the future. Perspectives from Norway, Sweden, Finland, Germany, and Poland were presented. Mitigation measures, particularly the artificial breakage of river ice covers and ice-jam flood forecasting, were shared. Advances in ice processes were also presented at the workshop, including state-of-the-art developments in tracking ice-floe velocities using particle tracking velocimetry, characterizing hanging dam ice, designing new ice-control structures, detecting, and monitoring river ice covers using composite imagery from both radar and optical satellite sensors, and calculating ice-jam flood hazards using a stochastic modelling approach. Full article
(This article belongs to the Special Issue Surface Water Quality Modelling)
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18 pages, 6072 KiB  
Article
Differentiating Nitrate Origins and Fate in a Semi-Arid Basin (Tunisia) via Geostatistical Analyses and Groundwater Modelling
by Kaouther Ncibi, Micòl Mastrocicco, Nicolò Colombani, Gianluigi Busico, Riheb Hadji, Younes Hamed and Khan Shuhab
Water 2022, 14(24), 4124; https://doi.org/10.3390/w14244124 - 18 Dec 2022
Cited by 26 | Viewed by 3345
Abstract
Despite efforts to protect the hydrosystems from increasing pollution, nitrate (NO3−) remains a major groundwater pollutant worldwide, and determining its origin is still crucial and challenging. To disentangle the origins and fate of high NO3− (>900 mg/L) in [...] Read more.
Despite efforts to protect the hydrosystems from increasing pollution, nitrate (NO3−) remains a major groundwater pollutant worldwide, and determining its origin is still crucial and challenging. To disentangle the origins and fate of high NO3− (>900 mg/L) in the Sidi Bouzid North basin (Tunisia), a numerical groundwater flow model (MODFLOW-2005) and an advective particle tracking (MODPATH) have been combined with geostatistical analyses on groundwater quality and hydrogeological characterization. Correlations between chemical elements and Principal Component Analysis (PCA) suggested that groundwater quality was primarily controlled by evaporite dissolution and subsequently driven by processes like dedolomitization and ion exchange. PCA indicated that NO3− origin is linked to anthropic (unconfined aquifer) and geogenic (semi-confined aquifer) sources. To suggest the geogenic origin of NO3− in the semi-confined aquifer, the multi-aquifer groundwater flow system and the forward and backward particle tracking was simulated. The observed and calculated hydraulic heads displayed a good correlation (R2 of 0.93). The residence time of groundwater with high NO3− concentrations was more significant than the timespan during which chemical fertilizers were used, and urban settlements expansion began. This confirmed the natural origin of NO3− associated with pre-Triassic embankment landscapes and located on domed geomorphic surfaces with a gypsum, phosphate, or clay cover. Full article
(This article belongs to the Special Issue Groundwater Hydrological Model Simulation)
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15 pages, 1786 KiB  
Article
Evaluation of the Adsorptive Performances of Rapeseed Waste in the Removal of Toxic Metal Ions in Aqueous Media
by Teodora Arsenie, Irina Gabriela Cara, Maria-Cristina Popescu, Iuliana Motrescu and Laura Bulgariu
Water 2022, 14(24), 4108; https://doi.org/10.3390/w14244108 - 16 Dec 2022
Cited by 28 | Viewed by 2262
Abstract
Rapeseed seeds are one of the most important categories of raw materials used to obtain biofuels. However, the biomass resulting after oil extraction is still considered waste, for which valorization solutions are sought. In this study, we propose the use of this type [...] Read more.
Rapeseed seeds are one of the most important categories of raw materials used to obtain biofuels. However, the biomass resulting after oil extraction is still considered waste, for which valorization solutions are sought. In this study, we propose the use of this type of residual biomass (rapeseed waste biomass (RWB)) as a biosorbent for the removal of toxic metal ions from aqueous media. Two toxic metal ions were selected for the experimental studies, namely: Pb(II) and Hg(II). The optimal biosorption conditions, for both metal ions, were selected based on response surface methodology and were verified experimentally in batch systems. More than 92% of the initial amount of Pb(II) and Hg(II) are retained under the following conditions: pH = 6.5 for Pb(II) and 4.0 for Hg(II); biosorbent dosage = 4.0 g/L; contact time = 3 h; temperature = 25 ± 1 °C. Isotherm (Langmuir, Freundlich and Temkin models) and kinetic (pseudo-first order, pseudo-second order and intra-particle diffusion models) modelling of the experimental data were used for the quantitative evaluation of both biosorption processes. Although the Langmuir maximum biosorption capacities are different (higher in the case of Pb(II) (61.97 mg/g) than in the case of Hg(II) (51.32 mg/g)), the pseudo-second order kinetic constants have the same order of magnitude. This shows that the retention of both metal ions involves similar elementary steps and that RWB behaves as a typical biosorbent. These characteristics, together with the very good desorption behavior, provide a complete picture of the possible applications of this waste in environmental decontamination processes. Full article
(This article belongs to the Special Issue Advances in Wastewater Treatment Processes)
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27 pages, 1133 KiB  
Review
Bioponics as a Promising Approach to Sustainable Agriculture: A Review of the Main Methods for Producing Organic Nutrient Solution for Hydroponics
by Iris Szekely and M. Haïssam Jijakli
Water 2022, 14(23), 3975; https://doi.org/10.3390/w14233975 - 6 Dec 2022
Cited by 35 | Viewed by 18395
Abstract
Hydroponics is a soilless cultivation technique in which plants are grown in a nutrient solution typically made from mineral fertilizers. This alternative to soil farming can be advantageous in terms of nutrient and water use efficiency, plant pest management, and space use. However, [...] Read more.
Hydroponics is a soilless cultivation technique in which plants are grown in a nutrient solution typically made from mineral fertilizers. This alternative to soil farming can be advantageous in terms of nutrient and water use efficiency, plant pest management, and space use. However, developing methods to produce nutrient solutions based on local organic materials is crucial to include hydroponics within a perspective of sustainability. They would also allow hydroponics to be developed in any context, even in remote areas or regions that do not have access to commercial fertilizers. This emerging organic form of hydroponics, which can be qualified as “bioponics”, typically recycles organic waste into a nutrient-rich solution that can be used for plant growth. Many methods have been developed and tested in the past three decades, leading to greatly heterogenous results in terms of plant yield and quality. This review describes the main organic materials used to produce nutrient solutions and characterizes and categorizes the different types of methods. Four main categories emerged: a “tea”-type method, an aerobic microbial degradation method, an anaerobic digestion method, and a combined anaerobic-aerobic degradation method. The advantages and drawbacks of each technique are discussed, as well as potential lines of improvement. This aims at better understanding the links between agronomic results and the main biochemical processes involved during the production, as well as discussing the most suitable method for certain plants and/or contexts. Full article
(This article belongs to the Special Issue New Advances in Hydroponics and Aquaponics for Urban Agriculture)
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11 pages, 987 KiB  
Review
Advances in the Study of Heavy Metal Adsorption from Water and Soil by Modified Biochar
by Yizhuo Wang, He Li and Shaohua Lin
Water 2022, 14(23), 3894; https://doi.org/10.3390/w14233894 - 29 Nov 2022
Cited by 38 | Viewed by 10191
Abstract
Heavy metal contamination in water and soil has gradually become a concern with the development of industry in recent years and may pose a serious threat to human health if left untreated. Biochar is commonly used as an adsorbent/immobilizer of heavy metals from [...] Read more.
Heavy metal contamination in water and soil has gradually become a concern with the development of industry in recent years and may pose a serious threat to human health if left untreated. Biochar is commonly used as an adsorbent/immobilizer of heavy metals from water and substrates because of its wide—ranging raw materials, low production cost, and good adsorption performance. Based on the adsorption mechanism of biochar, this paper analyzes different modification methods of biochar, aiming to provide an effective material for the treatment of heavy metals from water and sediment and provide a certain reference for its application to practical projects. Full article
(This article belongs to the Special Issue Advances in Wastewater Treatment: Resources Recovery, Energy Neutralization, Water Reuse)
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19 pages, 6164 KiB  
Article
Shallow Water Bathymetry Mapping from ICESat-2 and Sentinel-2 Based on BP Neural Network Model
by Xiaozu Guo, Xiaoyi Jin and Shuanggen Jin
Water 2022, 14(23), 3862; https://doi.org/10.3390/w14233862 - 27 Nov 2022
Cited by 25 | Viewed by 4583
Abstract
Accurate shallow water bathymetry data are essential for coastal construction and management, marine traffic, and shipping. With the development of remote sensing satellites and sensors, the satellite-derived bathymetry (SDB) method has been widely used for bathymetry in shallow water areas. However, traditional satellite [...] Read more.
Accurate shallow water bathymetry data are essential for coastal construction and management, marine traffic, and shipping. With the development of remote sensing satellites and sensors, the satellite-derived bathymetry (SDB) method has been widely used for bathymetry in shallow water areas. However, traditional satellite bathymetry requires in-situ bathymetric data. Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) with the advanced high-resolution topographic laser altimeter system (ATLAS) provides a new technical tool and makes up for the shortcomings of traditional bathymetric methods in shallow waters. In this study, a new method is proposed to automatically detect photons reflected from the shallow seafloor with ICESat-2 altimetry data. Two satellite bathymetry models were trained, to obtain shallow water depth from Sentinel-2 satellite images. First, sea surface and seafloor signal photons from ICESat-2 were detected in the Oahu (in the U.S. Hawaiian Islands) and St. Thomas (in the U.S. Virgin Islands) sampling areas, to obtain water depths along the surface track. The results show that the RMSE is between 0.35 and 0.71 m and the R2 is greater than 0.92, when compared to the airborne LiDAR bathymetry (ALB) data in the field. Second, the ICESat-2 bathymetric points from Oahu Island are used to train the Back Propagation (BP) neural network model and obtain the SDB. The RMSE is between 0.97 and 1.43 m and the R2 is between 0.90 and 0.96, which are better than the multi-band ratio model with RMSE of 1.03–1.57 m and R2 of 0.89–0.95. The results show that the BP neural network model can effectively improve bathymetric accuracy, when compared to the traditional multi-band ratio model. This approach can obtain shallow water bathymetry more easily, without the in-situ bathymetric data. Therefore, it extends to a greater extent with the free ICESat-2 and Sentinel-2 satellite data for bathymetry in shallow water areas, such as coastal, island and inland water bodies. Full article
(This article belongs to the Special Issue Application of Ocean Colour Remote Sensing in Turbidity Monitoring)
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23 pages, 3904 KiB  
Article
Extreme Rainfall Indices in Southern Levant and Related Large-Scale Atmospheric Circulation Patterns: A Spatial and Temporal Analysis
by Ala A. M. Salameh, Matilde García-Valdecasas Ojeda, María Jesús Esteban-Parra, Yolanda Castro-Díez and Sonia R. Gámiz-Fortis
Water 2022, 14(23), 3799; https://doi.org/10.3390/w14233799 - 22 Nov 2022
Cited by 15 | Viewed by 4021
Abstract
This study aims to provide a comprehensive spatio-temporal analysis of the annual and seasonal extreme rainfall indices over the southern Levant from 1970 to 2020. For this, temporal and spatial trends of 15 climate extreme indices based on daily precipitation at 66 stations [...] Read more.
This study aims to provide a comprehensive spatio-temporal analysis of the annual and seasonal extreme rainfall indices over the southern Levant from 1970 to 2020. For this, temporal and spatial trends of 15 climate extreme indices based on daily precipitation at 66 stations distributed across Israel and Palestine territories were annually and seasonally analyzed through the nonparametric Mann–Kendall test and the Sen’s slope estimator. The annual averages for frequency-based extreme indices exhibited decreasing trends, significantly for the Consecutive Dry Days. In contrast, the percentiles- and intensity-based extreme indices showed increasing trends, significant for extremely wet days, Max 1- and 3-day precipitation amount indices. The study area had expanding periods of extreme dry spells for spring and correspondingly shortening extreme wet spells for spring, winter and the combined winter–spring. Moreover, most of spring indices showed negative trends. Conversely, most winter indices displayed positive trends. Regarding the influence of large-scale circulation patterns, the North Sea Caspian pattern, the Western Mediterranean Oscillation, and ENSO were the primary regulators of the winter, spring, and autumn extreme indices, respectively. These findings contribute to a better understanding of extreme rainfall variability in the Levant region and could be utilized in the management of water resources, drought monitoring, and flood control. Full article
(This article belongs to the Special Issue Impacts of Climate Change on Hydrology and Water Resources)
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20 pages, 5191 KiB  
Review
The Baltic Sea under Anthropopressure—The Sea of Paradoxes
by Aldona Dobrzycka-Krahel and Magdalena Bogalecka
Water 2022, 14(22), 3772; https://doi.org/10.3390/w14223772 - 20 Nov 2022
Cited by 29 | Viewed by 10777
Abstract
The Baltic Sea is a unique ecosystem that is especially sensitive to anthropogenic pressure. We analysed human pressure in this sea, which may be considered as paradoxes. One of these, is paradox of “marine” pollution. The Baltic Sea is almost totally surrounded by [...] Read more.
The Baltic Sea is a unique ecosystem that is especially sensitive to anthropogenic pressure. We analysed human pressure in this sea, which may be considered as paradoxes. One of these, is paradox of “marine” pollution. The Baltic Sea is almost totally surrounded by land and therefore sources of marine pollution are located mainly on the land. Another paradox is connected with shipping traffic intensity and maritime accidents. The Baltic Sea is characterised by the large shipping traffic, but the last decades’ data show only more than 100, usually insignificant and minor, accidents and incidents at the Baltic Sea every year. Although the Baltic Sea is characterised by a relatively low native species number compared to most marine systems, it is home to alien species. Moreover, despite the common opinion that a sea is a source of living marine resources, available riches in the Baltic Sea under anthropopressure are limited and the sea does not give expected benefits—it is the next paradox. The fact that the Baltic Sea is warming rapidly due to climate change and more suitable for bathing when the weather is favourable, massive algae growth often prevents it. Therefore, strong human impact on the Baltic Sea should be limited and sustainable use of this sea should be prioritised. Full article
(This article belongs to the Special Issue Seas under Anthropopressure)
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14 pages, 3130 KiB  
Article
Application of Machine Learning Techniques for the Estimation of the Safety Factor in Slope Stability Analysis
by Yaser Ahangari Nanehkaran, Tolga Pusatli, Jin Chengyong, Junde Chen, Ahmed Cemiloglu, Mohammad Azarafza and Reza Derakhshani
Water 2022, 14(22), 3743; https://doi.org/10.3390/w14223743 - 18 Nov 2022
Cited by 73 | Viewed by 6511
Abstract
Slope stability is the most important stage in the stabilization process for different scale slopes, and it is dictated by the factor of safety (FS). The FS is a relationship between the geotechnical characteristics and the slope behavior under various loading conditions. Thus, [...] Read more.
Slope stability is the most important stage in the stabilization process for different scale slopes, and it is dictated by the factor of safety (FS). The FS is a relationship between the geotechnical characteristics and the slope behavior under various loading conditions. Thus, the application of an accurate procedure to estimate the FS can lead to a fast and precise decision during the stabilization process. In this regard, using computational models that can be operated accurately is strongly needed. The performance of five different machine learning models to predict the slope safety factors was investigated in this study, which included multilayer perceptron (MLP), support vector machines (SVM), k-nearest neighbors (k-NN), decision tree (DT), and random forest (RF). The main objective of this article is to evaluate and optimize the various machine learning-based predictive models regarding FS calculations, which play a key role in conducting appropriate stabilization methods and stabilizing the slopes. As input to the predictive models, geo-engineering index parameters, such as slope height (H), total slope angle (β), dry density (γd), cohesion (c), and internal friction angle (φ), which were estimated for 70 slopes in the South Pars region (southwest of Iran), were considered to predict the FS properly. To prepare the training and testing data sets from the main database, the primary set was randomly divided and applied to all predictive models. The predicted FS results were obtained for testing (30% of the primary data set) and training (70% of the primary data set) for all MLP, SVM, k-NN, DT, and RF models. The models were verified by using a confusion matrix and errors table to conclude the accuracy evaluation indexes (i.e., accuracy, precision, recall, and f1-score), mean squared error (MSE), mean absolute error (MAE), and root mean square error (RMSE). According to the results of this study, the MLP model had the highest evaluation with a precision of 0.938 and an accuracy of 0.90. In addition, the estimated error rate for the MLP model was MAE = 0.103367, MSE = 0.102566, and RMSE = 0.098470. Full article
(This article belongs to the Special Issue Application of AI and UAV Techniques in Urban Water Science)
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18 pages, 3963 KiB  
Article
Study on the Application of Shell-Activated Carbon for the Adsorption of Dyes and Antibiotics
by Jinlong Wang, Rui Wang, Jingqian Ma and Yongjun Sun
Water 2022, 14(22), 3752; https://doi.org/10.3390/w14223752 - 18 Nov 2022
Cited by 34 | Viewed by 6240
Abstract
In this study, we prepared homemade fruit shell-activated carbon (SAC) with efficient adsorption of new pollutants and used it in the removal of methylene blue dye (MB) and ofloxacin antibiotic (OFL) in water. We fitted the experimental data for MB and OFL adsorption [...] Read more.
In this study, we prepared homemade fruit shell-activated carbon (SAC) with efficient adsorption of new pollutants and used it in the removal of methylene blue dye (MB) and ofloxacin antibiotic (OFL) in water. We fitted the experimental data for MB and OFL adsorption with isothermal and kinetic models and performed extensive characterization to study the properties of SAC. We also studied the effects of solution pH, dosage amount, initial concentration, and coexisting ions on the adsorption capacity. The results show that SAC has a rich pore structure, and electrostatic interactions are its main adsorption mechanism. Adjusting the solution pH by changing the SAC dosage and removing the K+, SO42−, and Cu2+ could increase the removal of MB and OFL to 99.9% and 97.6%, respectively. In addition, the adsorption capacity of SAC for MB remained at more than 50% of the initial state after three iterations of adsorption regeneration, showing a good regeneration ability. These results show the potential of SAC in replacing conventional activated carbon to remove new pollutants. Full article
(This article belongs to the Special Issue Water-Sludge-Nexus)
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19 pages, 5177 KiB  
Article
Deformation Prediction System of Concrete Dam Based on IVM-SCSO-RF
by Shi Zhang, Dongjian Zheng and Yongtao Liu
Water 2022, 14(22), 3739; https://doi.org/10.3390/w14223739 - 17 Nov 2022
Cited by 19 | Viewed by 2381
Abstract
Deformation prediction is an important part of concrete dam safety monitoring. In recent years, the random forest (RF) algorithm has attracted more and more attention in the field of dam safety monitoring because of its fast speed and strong generalization ability. However, the [...] Read more.
Deformation prediction is an important part of concrete dam safety monitoring. In recent years, the random forest (RF) algorithm has attracted more and more attention in the field of dam safety monitoring because of its fast speed and strong generalization ability. However, the performance of RF is easily affected by many factors, such as the drift of measured value in displacement and the inappropriate setting of parameters of RF. To solve the above problems, the indicator variable model (IVM) is used to identify and eliminate the drift of measured values in this paper, and the sand cat swarm optimization (SCSO) is applied to optimize RF for the first time. On the grounds of this, a deformation prediction system of a concrete dam based on the IVM and RF algorithm optimized by SCSO is proposed. The case study shows that IVM can correct the interference of monitoring data accurately, and the maximum error rate is less than 3%; in the aspect of parameter optimization of RF, the results of the SCSO algorithm are obviously better than those of the TAE method and PSO algorithm, and the corresponding OOB error is the minimum; in terms of prediction performance, compared with TAE-RF, PSO-RF, LSTM and SVM, SCSO-RF has higher accuracy and stronger stability, and its SSE and MSE are reduced by at least 91%, MAE and RMSE are reduced by at least 71%, and R2 is very close to 1. The results of study provide a new method for the automatic online evaluation of dam safety performance. Full article
(This article belongs to the Special Issue Dam Safety. Protection against Overtopping and Prevention of Geo-Structural Failure)
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22 pages, 10541 KiB  
Article
Multi-Step Ahead Probabilistic Forecasting of Daily Streamflow Using Bayesian Deep Learning: A Multiple Case Study
by Fatemeh Ghobadi and Doosun Kang
Water 2022, 14(22), 3672; https://doi.org/10.3390/w14223672 - 14 Nov 2022
Cited by 22 | Viewed by 4745
Abstract
In recent decades, natural calamities such as drought and flood have caused widespread economic and social damage. Climate change and rapid urbanization contribute to the occurrence of natural disasters. In addition, their destructive impact has been altered, posing significant challenges to the efficiency, [...] Read more.
In recent decades, natural calamities such as drought and flood have caused widespread economic and social damage. Climate change and rapid urbanization contribute to the occurrence of natural disasters. In addition, their destructive impact has been altered, posing significant challenges to the efficiency, equity, and sustainability of water resources allocation and management. Uncertainty estimation in hydrology is essential for water resources management. By quantifying the associated uncertainty of reliable hydrological forecasting, an efficient water resources management plan is obtained. Moreover, reliable forecasting provides significant future information to assist risk assessment. Currently, the majority of hydrological forecasts utilize deterministic approaches. Nevertheless, deterministic forecasting models cannot account for the intrinsic uncertainty of forecasted values. Using the Bayesian deep learning approach, this study developed a probabilistic forecasting model that covers the pertinent subproblem of univariate time series models for multi-step ahead daily streamflow forecasting to quantify epistemic and aleatory uncertainty. The new model implements Bayesian sampling in the Long short-term memory (LSTM) neural network by using variational inference to approximate the posterior distribution. The proposed method is verified with three case studies in the USA and three forecasting horizons. LSTM as a point forecasting neural network model and three probabilistic forecasting models, such as LSTM-BNN, BNN, and LSTM with Monte Carlo (MC) dropout (LSTM-MC), were applied for comparison with the proposed model. The results show that the proposed Bayesian long short-term memory (BLSTM) outperforms the other models in terms of forecasting reliability, sharpness, and overall performance. The results reveal that all probabilistic forecasting models outperformed the deterministic model with a lower RMSE value. Furthermore, the uncertainty estimation results show that BLSTM can handle data with higher variation and peak, particularly for long-term multi-step ahead streamflow forecasting, compared to other models. Full article
(This article belongs to the Special Issue Artificial Intelligence Techniques in Hydrology and Water Resources Management)
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18 pages, 3560 KiB  
Article
SPI-Based Drought Classification in Italy: Influence of Different Probability Distribution Functions
by Benedetta Moccia, Claudio Mineo, Elena Ridolfi, Fabio Russo and Francesco Napolitano
Water 2022, 14(22), 3668; https://doi.org/10.3390/w14223668 - 14 Nov 2022
Cited by 27 | Viewed by 3657
Abstract
Drought is ranked second in type of natural phenomena associated with billion dollars weather disaster during the past years. It is estimated that in EU countries the number of people affected by drought was increased by 20% over the last decades. It is [...] Read more.
Drought is ranked second in type of natural phenomena associated with billion dollars weather disaster during the past years. It is estimated that in EU countries the number of people affected by drought was increased by 20% over the last decades. It is widely recognized that the Standardized Precipitation Index (SPI) can effectively provide drought characteristics in time and space. The paper questions the standard approach to estimate the SPI based on the Gamma probability distribution function, assessing the fitting performance of different biparametric distribution laws to monthly precipitation data. We estimate SPI time series, for different scale of temporal aggregation, on an unprecedented dataset consisting of 332 rain gauge stations deployed across Italy with observations recorded between 1951 and 2000. Results show that the Lognormal distribution performs better than the Gamma in fitting the monthly precipitation data at all time scales, affecting drought characteristics estimated from SPI signals. However, drought events detected using the original and the best fitting approaches does not diverge consistently in terms of return period. This suggests that the SPI in its original formulation can be applied for a reliable detection of drought events and for promoting mitigation strategies over the Italian peninsula. Full article
(This article belongs to the Section Hydrology)
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13 pages, 2329 KiB  
Article
Assessment of Spatial Heterogeneity of Soil Moisture in the Critical Zone of Gully Consolidation and Highland Protection
by Aidi Huo, Zhixin Zhao, Pingping Luo, Chunli Zheng, Jianbing Peng and Mohamed EL-Sayed Abuarab
Water 2022, 14(22), 3674; https://doi.org/10.3390/w14223674 - 14 Nov 2022
Cited by 17 | Viewed by 2473
Abstract
The Gully Consolidation and Highland Protection (GCHP) project (such as for gully head landfills), a consideration of soil and water conservation measures, has been explored and developed continuously in recent decades in the Chinese Loess Plateau. Using high-precision images taken by drones to [...] Read more.
The Gully Consolidation and Highland Protection (GCHP) project (such as for gully head landfills), a consideration of soil and water conservation measures, has been explored and developed continuously in recent decades in the Chinese Loess Plateau. Using high-precision images taken by drones to extract the topography of the basin, the changes in vegetation and land use were also analyzed. The observation of soil moisture in the critical gully head area of the GCHP was carried out. The results indicated that the critical zones of the GCHP project implementation include the gully head landfill, the gully, and the highland farming area. The soil moisture of the landfill area was 6.91% and 23.61% higher than that of the gully and farming area, respectively, with obvious spatial heterogeneity. The soil sand content in the gully head landfill area was higher than that in the gully area and the agricultural area of the plateau. The main reason for the high soil moisture in the gully head landfill area is that the terrain at the outlet is low, and it is at the lowest point of the whole basin. Analyzing the spatial distribution of soil moisture can point out the direction for the monitoring, prevention, and treatment of geological disasters, such as landslides and debris flow, induced by water erosion. This study will help to understand in detail the spatial heterogeneity and influencing factors of soil moisture under the implementation of the GCHP and improve the GCHP project management system. Full article
(This article belongs to the Special Issue Landslides and Sediment Disasters Prevention)
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19 pages, 4350 KiB  
Article
Hydrological Drought Forecasting Using a Deep Transformer Model
by Amobichukwu C. Amanambu, Joann Mossa and Yin-Hsuen Chen
Water 2022, 14(22), 3611; https://doi.org/10.3390/w14223611 - 9 Nov 2022
Cited by 34 | Viewed by 6863
Abstract
Hydrological drought forecasting is essential for effective water resource management planning. Innovations in computer science and artificial intelligence (AI) have been incorporated into Earth science research domains to improve predictive performance for water resource planning and disaster management. Forecasting of future hydrological drought [...] Read more.
Hydrological drought forecasting is essential for effective water resource management planning. Innovations in computer science and artificial intelligence (AI) have been incorporated into Earth science research domains to improve predictive performance for water resource planning and disaster management. Forecasting of future hydrological drought can assist with mitigation strategies for various stakeholders. This study uses the transformer deep learning model to forecast hydrological drought, with a benchmark comparison with the long short-term memory (LSTM) model. These models were applied to the Apalachicola River, Florida, with two gauging stations located at Chattahoochee and Blountstown. Daily stage-height data from the period 1928–2022 were collected from these two stations. The two deep learning models were used to predict stage data for five different time steps: 30, 60, 90, 120, and 180 days. A drought series was created from the forecasted values using a monthly fixed threshold of the 75th percentile (75Q). The transformer model outperformed the LSTM model for all of the timescales at both locations when considering the following averages: MSE=0.11, MAE=0.21, RSME=0.31, and R2=0.92 for the Chattahoochee station, and MSE=0.06, MAE=0.19, RSME=0.23, and R2=0.93 for the Blountstown station. The transformer model exhibited greater accuracy in generating the same drought series as the observed data after applying the 75Q threshold, with few exceptions. Considering the evaluation criteria, the transformer deep learning model accurately forecasts hydrological drought in the Apalachicola River, which could be helpful for drought planning and mitigation in this area of contested water resources, and likely has broad applicability elsewhere. Full article
(This article belongs to the Section New Sensors, New Technologies and Machine Learning in Water Sciences)
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18 pages, 3115 KiB  
Article
Geochemical Characterisation and Health Concerns of Mineral Bottled Waters in Catalonia (North-Eastern Spain)
by Josefina C. Tapias, Raquel Melián, Alex Sendrós, Xavier Font and Albert Casas
Water 2022, 14(21), 3581; https://doi.org/10.3390/w14213581 - 7 Nov 2022
Cited by 12 | Viewed by 5379
Abstract
Spain currently produces around 7000 million litres of mineral water a year, of which about 20% is produced in Catalonia, and there is a need for greater regulation and research into bottled waters and their impact on human health. A total of 29 [...] Read more.
Spain currently produces around 7000 million litres of mineral water a year, of which about 20% is produced in Catalonia, and there is a need for greater regulation and research into bottled waters and their impact on human health. A total of 29 samples were analysed from different brands of commercially bottled water, and 71 chemical elements were determined in each sample. The aim was to classify each brand based on composition, compare lithological origins, verify compliance with international standards for drinking water, and report benefits for human health. More than 60% of the samples were of the calcium bicarbonate type, had a low mineral content, and were associated with granitic aquifers, ranging from leucogranites to granodiorites. In contrast, 17% were of the sodium bicarbonate type, had harder waters, and were related to thermal springs. The thermal springs of the bottled waters from the Montseny-Guilleres massif (Vichy Catalán, Malavella, and San Narciso) emerge at a temperature of 60 °C with their own natural gas. Two samples exceeded European standards for As and Hg concentrations in water for human consumption, while one showed a concentration of U greater than that set out in international recommendations. Full article
(This article belongs to the Special Issue Geochemistry of Mineral Groundwater)
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18 pages, 5539 KiB  
Article
Adsorption of Methylene Blue by Coal-Based Activated Carbon in High-Salt Wastewater
by Jinlong Wang, Jingqian Ma and Yongjun Sun
Water 2022, 14(21), 3576; https://doi.org/10.3390/w14213576 - 7 Nov 2022
Cited by 38 | Viewed by 6737
Abstract
High-salt printing and dyeing wastewater is a difficult industrial wastewater to treat. Coal-based activated carbon (CBAC) can be used as an adsorbent to treat high-salt printing and dyeing wastewater and realize the resource utilization of CBAC. In this study, simulated wastewater that contained [...] Read more.
High-salt printing and dyeing wastewater is a difficult industrial wastewater to treat. Coal-based activated carbon (CBAC) can be used as an adsorbent to treat high-salt printing and dyeing wastewater and realize the resource utilization of CBAC. In this study, simulated wastewater that contained methylene blue (MB) was used as the research object, and CBAC was used as the adsorbent. The effects of CBAC dosage, NaCl concentration, coexisting ions, adsorption time, MB concentration, humic acid concentration, and solution pH on the adsorption performance of CBAC with MB were discussed. The results showed that when the CBAC dosage was 0.6 g/L, the solution pH was greater than 6, the adsorption time was 8 h, the adsorption temperature was 308 K, and the MB concentration was 10 mg/L. Thus, the maximum adsorption capacity of CBAC with MB was obtained. The maximum adsorption capacity and removal rate were 15.5 mg/L and 90%, respectively. High-salt wastewater can inhibit the adsorption of methylene blue by coal-based activated carbon. In addition, 20 g/L of NaCl reduced the adsorption capacity of coal-based activated carbon by 1.8 mg/g. Compared to the other coexisting ions, the influence of the presence of Cu2+ and Fe3+ on the removal of methylene blue was greater. However, when Cu2+, Fe3+ and high-salt wastewater coexist, the inhibition effect decreases. Full article
(This article belongs to the Special Issue Water-Sludge-Nexus)
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31 pages, 2963 KiB  
Review
A General Overview of Heterogeneous Photocatalysis as a Remediation Technology for Wastewaters Containing Pharmaceutical Compounds
by Donia Friedmann
Water 2022, 14(21), 3588; https://doi.org/10.3390/w14213588 - 7 Nov 2022
Cited by 48 | Viewed by 9500
Abstract
The presence of persistent, difficult to degrade pharmaceutical compounds in wastewaters is a significant environmental concern. While heterogeneous photocatalysis can degrade a range of pharmaceutical compounds, as a technology, it is yet to be applied. Current research on heterogeneous photocatalysis for pharmaceutical removal [...] Read more.
The presence of persistent, difficult to degrade pharmaceutical compounds in wastewaters is a significant environmental concern. While heterogeneous photocatalysis can degrade a range of pharmaceutical compounds, as a technology, it is yet to be applied. Current research on heterogeneous photocatalysis for pharmaceutical removal is focused on the development of photocatalytic materials that are both efficient photocatalysts and solar driven as well as materials that combine both adsorption and photocatalysis. The formation of toxic by-products during photocatalytic degradation can be an issue, hence, mechanistic studies to identify reaction pathways and intermediates are important and are discussed in this review. The potential application of photocatalytic systems coupled with other technologies, to achieve complete pollutant removal and avoid toxin formation are also discussed. Given the broad range of properties of these pharmaceutical compounds and their corresponding wastewater matrices, each system needs to be optimised accordingly, with the need for pilot scale studies. Other than end of pipe solutions to reduce the occurrence of pharmaceutical pollutants in the environment, a comprehensive environmental management approach involving strategies such as the reduction of pharmaceutical prescriptions and the introduction of take back schemes are also needed to achieve a reduction of pharmaceutical compounds in the environment. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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29 pages, 2953 KiB  
Review
Insights into the Domestic Wastewater Treatment (DWWT) Regimes: A Review
by Bhupendra Koul, Dhananjay Yadav, Swati Singh, Manoj Kumar and Minseok Song
Water 2022, 14(21), 3542; https://doi.org/10.3390/w14213542 - 4 Nov 2022
Cited by 98 | Viewed by 24576
Abstract
It is expected that, by 2050, the rapid rise in population and simultaneous urbanization shall deplete clean water supplies. Domestic wastewater (DWW) contains inorganic and organic components that can be harmful to aquatic organisms. Traditional remediation approaches (physical, chemical and biological) can be [...] Read more.
It is expected that, by 2050, the rapid rise in population and simultaneous urbanization shall deplete clean water supplies. Domestic wastewater (DWW) contains inorganic and organic components that can be harmful to aquatic organisms. Traditional remediation approaches (physical, chemical and biological) can be used on-site or off-site to purify polluted domestic water (activated sludge, built-wetlands, stabilization ponds, trickling filters and membrane bioreactors), and each has its own advantages and limitations. Biosorption through microorganisms, bacteria (microbe-mediated remediation), fungi (mycoremediation) and algae (phycoremediation) has shown promising results in removing toxic chemicals and nutrients. The type of waste and its concentration, heterogeneity level and percentage of clean-up required; and the feasibility of the clean-up technique and its efficiency, practicability, operational difficulties, environmental impact and treatment costs are all factors that are to be considered when choosing a technique for domestic wastewater treatment (DWWT). This review focuses on the roles of conventional methods in DWWT, including their merits, demerits and future prospects. It promotes the concept of “reduce, reuse and recycle” of DWWT and also highlights the problem of emerging contaminants in WWT regimes. We provide insights into the different membrane filtration procedures and water purification techniques and the synergism of conventional and non-conventional WWT strategies for human and environment health security. Full article
(This article belongs to the Special Issue Water Quality Engineering and Wastewater Treatment Ⅱ)
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14 pages, 1104 KiB  
Article
Comparative Influence of Biochar and Zeolite on Soil Hydrological Indices and Growth Characteristics of Corn (Zea mays L.)
by Mohammad Ghorbani, Elnaz Amirahmadi, Petr Konvalina, Jan Moudrý, Jan Bárta, Marek Kopecký, Răzvan Ionuț Teodorescu and Roxana Dana Bucur
Water 2022, 14(21), 3506; https://doi.org/10.3390/w14213506 - 2 Nov 2022
Cited by 33 | Viewed by 4772
Abstract
Biochar and zeolite, due to their porous structure, are supposed to be appropriate soil amendments especially in agricultural areas with a lack of water or unsuitable soils with coarse texture. Two soil additions that are intended to assist an increase soil water content [...] Read more.
Biochar and zeolite, due to their porous structure, are supposed to be appropriate soil amendments especially in agricultural areas with a lack of water or unsuitable soils with coarse texture. Two soil additions that are intended to assist an increase soil water content (AWC) are biochar and zeolite. With this aim, the effects of biochar and zeolite at two levels of 5 and 10 t ha−1 (known as B5, B10, Z5, and Z10) on soil hydrological properties and consequently corn growth were investigated in this study. The results showed that the application of B5 and B10 significantly improved AWC by 76% and 48% due to increasing soil micro- and meso-pores. The application of Z5 and Z10, associated with an increase of macro-pores in soil, enhanced saturated hydraulic conductivity (Ks) up to 174% and 303% and caused losses. The highest specific surface area and mean weight diameter in soil obtained from B10 had an increase of 171% and 197% over the control. Biochar treatments considerably affected plant growth features and shoot nutrient content, whilst zeolite treatments had an impact that is much less apparent than that of biochar. Observations indicate that biochar greatly boosted nutrient availability and water retention in the soil by raising the share of micro- and mezzo-pores, respectively, and as a result, has benefited plant growth. Increasing the level of biochar application from 5 to 10% would have more positive effects on the water available in the soil and on plant root systems. In contrast, the high rate of application of zeolite particles due to coarseness and adding Na+ ions to the soil caused the dispersion of soil particles, the destruction of soil structure, increasing Ks and water loss and consequently a reduction in plant growth. Full article
(This article belongs to the Special Issue Environmental Impact Assessment on Soil and Water Conservation)
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29 pages, 2028 KiB  
Review
Aging Process of Microplastics in the Aquatic Environments: Aging Pathway, Characteristic Change, Compound Effect, and Environmentally Persistent Free Radicals Formation
by Cong Li, Bo Jiang, Jiaqi Guo, Chunmeng Sun, Changjie Shi, Saikai Huang, Wang Liu, Chengzhang Wu and Yunshu Zhang
Water 2022, 14(21), 3515; https://doi.org/10.3390/w14213515 - 2 Nov 2022
Cited by 60 | Viewed by 10546
Abstract
Plastic wastes are becoming one of the most serious environmental pollutants because of their high antidegradation properties and the damage they cause to human health. More seriously, plastics can become smaller in size and form microplastics (MPs), attributing to the oxidation, weathering, and [...] Read more.
Plastic wastes are becoming one of the most serious environmental pollutants because of their high antidegradation properties and the damage they cause to human health. More seriously, plastics can become smaller in size and form microplastics (MPs), attributing to the oxidation, weathering, and fragmentation processes. The influx of MPs into water bodies seriously affects the quality of the aquatic environment. Therefore, it is necessary to summarize the aging process of MPs. In this review, we first provided an overview of the definition and source of MPs. Then we analyzed the potential aging pathways of MPs in the current aquatic environment and elaborated on the changes in the physicochemical properties of MPs during the aging process (e.g., particle size, crystallinity, thermodynamic properties, and surface functional groups). In addition, the possible synergistic contamination of MPs with other pollutants in the environment is illustrated. Finally, the mechanisms of generation and toxicity of environmental persistent free radicals (EPFRs) that may be generated during the photoaging of MPs were described, and the feasibility of using photoaged MPs as photosensitizers to catalyze photoreactive degradation of organic pollutants is proposed. Overall, this review provides a comprehensive and objective evaluation of the behavior of MPs in the aquatic environment. Full article
(This article belongs to the Special Issue Soluble Microbial Products and Perfluorinated Compounds in Wastewater Treatment)
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17 pages, 6688 KiB  
Article
Identification of Suitable Sites Using GIS for Rainwater Harvesting Structures to Meet Irrigation Demand
by Preeti Preeti, Yuri Shendryk and Ataur Rahman
Water 2022, 14(21), 3480; https://doi.org/10.3390/w14213480 - 31 Oct 2022
Cited by 24 | Viewed by 8221
Abstract
This study uses a multi-criteria decision analysis approach based on geographic information system (GIS) to identify suitable sites for rainwater harvesting (RWH) structures (such as farm dam, check dam and contour bund) to meet irrigation demand in Greater Western Sydney region, New South [...] Read more.
This study uses a multi-criteria decision analysis approach based on geographic information system (GIS) to identify suitable sites for rainwater harvesting (RWH) structures (such as farm dam, check dam and contour bund) to meet irrigation demand in Greater Western Sydney region, New South Wales, Australia. Data on satellite image, soil, climate, and digital elevation model (DEM) were stored in GIS layers and merged to create a ranking system, which were then used to identify suitable RWH (rainwater harvesting) areas. The resulting thematic layers (such as rainfall, land use/land cover, soil type, slope, runoff depth, drainage density, stream order and distance from road) were combined into one overlay to produce map of RWH suitability. The results showed that 9% of the study region is ‘very highly suitable’ and 25% is ‘highly suitable’. On the other hand, 36% of the area, distributed in the north-west, west and south-west of the study region, is ‘moderately suitable’. While 21% of the region, distributed in east and south-east part of the region, has ‘low suitability’ and 9% is found as ‘unsuitable area’. The findings of this research will contribute towards wider adoption of RWH in Greater Western Sydney region to meet irrigation demand. The developed methodology can be adapted to any other region/country. Full article
(This article belongs to the Special Issue Sustainable Water Futures: Climate, Community and Circular Economy)
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23 pages, 14521 KiB  
Article
Assessment of Urbanization-Induced Land-Use Change and Its Impact on Temperature, Evaporation, and Humidity in Central Vietnam
by Binh Quang Nguyen, Thanh-Nhan-Duc Tran, Maria Grodzka-Łukaszewska, Grzegorz Sinicyn and Venkataraman Lakshmi
Water 2022, 14(21), 3367; https://doi.org/10.3390/w14213367 - 24 Oct 2022
Cited by 39 | Viewed by 3804
Abstract
In the present day, the acceleration of urban surface heat impacts resulting from urbanization and industrialization is critical for citizens and municipal governments in developing-country cities. The previous key findings have indicated the association between urban surface heat and the following areas: forests, [...] Read more.
In the present day, the acceleration of urban surface heat impacts resulting from urbanization and industrialization is critical for citizens and municipal governments in developing-country cities. The previous key findings have indicated the association between urban surface heat and the following areas: forests, mixed agricultural land, built-up area, and water bodies. This study was motivated by a lack of knowledge regarding the variation of temperature, evaporation, and humidity in Central Vietnam’s major region. The non-parametric Mann–Kendall test, Sen’s slope estimator, and Landsat image analysis were employed to determine the trend and statistical significance of the variables across the 42-year study period for Da Nang city and Quang Nam province. Our results show that Da Nang city has a consistent trend with a high correlation between temperature, evaporation, and relative humidity, whereas Quang Nam province showed an inverse relationship between temperature and relative humidity since the beginning of the regional urbanization. The maximum, minimum, and mean temperatures have increased by at least 0.29 °C in Quang Nam province and 0.71 °C in Da Nang city since 2000. Between 1979 and 2021, the frequency of days with temperatures exceeding 35 °C has increased by two and seven days during the past decade at the meteorological stations in Da Nang and Tam Ky, respectively. The temperature in Da Nang city varied from 31.80 °C to 32.82 °C with high temperatures concentrated in urbanized regions with less coverage of small trees, plants, and water bodies. Thus, the results of this study will serve as a scientific basis for decision-makers and regional officials for land-use management and to increase community awareness of sustainable planning, particularly in Da Nang city and Quang Nam province in Central Vietnam. Full article
(This article belongs to the Section Water and Climate Change)
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22 pages, 5952 KiB  
Article
Synthesis and Investigation of TiO2/g-C3N4 Performance for Photocatalytic Degradation of Bromophenol Blue and Eriochrome Black T: Experimental Design Optimization and Reactive Oxygen Species Contribution
by Fadimatou Hassan, Pierre Bonnet, Jean Marie Dangwang Dikdim, Nadege Gatcha Bandjoun, Christophe Caperaa, Sadou Dalhatou, Abdoulaye Kane and Hicham Zeghioud
Water 2022, 14(20), 3331; https://doi.org/10.3390/w14203331 - 21 Oct 2022
Cited by 20 | Viewed by 5642
Abstract
Graphitic carbon nitride (g-C3N4) based photocatalyst was synthesized and the photocatalytic performance was investigated for the removal of Eriochrome Black T (EBT) and Bromophenol Blue (BPB) under UV irradiation. The prepared materials were characterized by SEM-EDX, XRD, Raman, FTIR [...] Read more.
Graphitic carbon nitride (g-C3N4) based photocatalyst was synthesized and the photocatalytic performance was investigated for the removal of Eriochrome Black T (EBT) and Bromophenol Blue (BPB) under UV irradiation. The prepared materials were characterized by SEM-EDX, XRD, Raman, FTIR and DRS. Higher degradation efficiency for the same initial concentrations of EBT and BPB in presence of TiO2/g-C3N4 have been achieved within 160 min of irradiation. The kinetic study showed that the photodegradation of BPB by TiO2/g-C3N4 follows pseudo-first-order kinetics with an R2 value of 0.98. The addition of persulfate (PS) in BPB solution improved the degradation yield from 8.81% to 80.14% within 20 min of UV light irradiation. A Box-Behnken model was developed from three factors and Response surface methodology (RSM) was employed to identify the optimum conditions for the treatment of BPB solution by TiO2/g-C3N4. The experimental values of degradation of BPB agreed with predicted values obtained from central composite design (CCD) analysis with an R2 value of 0.9999. The scavenger study revealed that superoxide radical anion (O2•−) plays a key role (68.89% of contribution) followed by OH• and h+ with 22.40% and 15.55% of contribution, respectively. This study has obviously exhibited the potential of TiO2/g-C3N4 composite as a promising catalyst for photocatalytic purposes. Full article
(This article belongs to the Special Issue Physicochemical Technology for Wastewater Treatment: Theory, Methods and Applications)
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18 pages, 6210 KiB  
Article
Comparing Performance of ANN and SVM Methods for Regional Flood Frequency Analysis in South-East Australia
by Amir Zalnezhad, Ataur Rahman, Nastaran Nasiri, Mehdi Vafakhah, Bijan Samali and Farhad Ahamed
Water 2022, 14(20), 3323; https://doi.org/10.3390/w14203323 - 20 Oct 2022
Cited by 19 | Viewed by 2886
Abstract
Design flood estimations at ungauged catchments are a challenging task in hydrology. Regional flood frequency analysis (RFFA) is widely used for this purpose. This paper develops artificial intelligence (AI)-based RFFA models (artificial neural networks (ANN) and support vector machine (SVM)) using data from [...] Read more.
Design flood estimations at ungauged catchments are a challenging task in hydrology. Regional flood frequency analysis (RFFA) is widely used for this purpose. This paper develops artificial intelligence (AI)-based RFFA models (artificial neural networks (ANN) and support vector machine (SVM)) using data from 181 gauged catchments in South-East Australia. Based on an independent testing, it is found that the ANN method outperforms the SVM (the relative error values for the ANN model range 33–54% as compared to 37–64% for the SVM). The ANN and SVM models generate more accurate flood quantiles for smaller return periods; however, for higher return periods, both the methods present a higher estimation error. The results of this study will help to recommend new AI-based RFFA methods in Australia. Full article
(This article belongs to the Special Issue Sustainable Water Futures: Climate, Community and Circular Economy)
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19 pages, 4275 KiB  
Article
Agro-Industrial Waste as Potential Heavy Metal Adsorbents and Subsequent Safe Disposal of Spent Adsorbents
by Daiana Simón, Cristina Palet, Agustín Costas and Adrián Cristóbal
Water 2022, 14(20), 3298; https://doi.org/10.3390/w14203298 - 19 Oct 2022
Cited by 37 | Viewed by 4697
Abstract
Water pollution is an environmental problem that affects the ecosystem and living beings. Adsorption is one of the best technologies for the removal of heavy metals. Since waste recovery is the basis of the Circular Economy, agro-industrial waste is emerging as low-cost adsorbents [...] Read more.
Water pollution is an environmental problem that affects the ecosystem and living beings. Adsorption is one of the best technologies for the removal of heavy metals. Since waste recovery is the basis of the Circular Economy, agro-industrial waste is emerging as low-cost adsorbents for these pollutants from wastewater. Residues of pine sawdust, sunflower seed hulls and corn residues mix were evaluated as adsorbents of synthetic aqueous solutions of Ni(II), Zn(II) and Cd(II). These residues were characterized to determine their structure and composition, and to understand the adsorption mechanism. Adsorption efficiencies and capacities for the adsorbents and adsorbates were determined and compared. From the obtained results, it is possible to affirm that all biomasses used are good alternatives to the synthetic materials, with adsorption efficiencies greater than 50%. The order of adsorption was Cd > Zn > Ni. At the concentration range checked, adsorption efficiencies decreased in sawdust when a mixture of all metals together was considered (as present in real sewage). Finally, the heavy metals were immobilized, with efficiencies over 88.5%, in clay ceramics (as brick’s precursors). This procedure would help to minimize the contamination that could be generated by the disposal of spent adsorbents, rarely explored in the literature. Full article
(This article belongs to the Special Issue Sustainable Processes for the Removing of Heavy Metals from Aqueous Solutions)
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15 pages, 5517 KiB  
Article
Spatiotemporal Variation and Influence Factors of Vegetation Cover in the Yellow River Basin (1982–2021) Based on GIMMS NDVI and MOD13A1
by Yi Cheng, Lijuan Zhang, Zhiqiang Zhang, Xueyin Li, Haiying Wang and Xu Xi
Water 2022, 14(20), 3274; https://doi.org/10.3390/w14203274 - 17 Oct 2022
Cited by 18 | Viewed by 3083
Abstract
Depicting the spatiotemporal dynamics of vegetation cover in the Yellow River Basin (YRB) and delineating the influences of climate change and human activities on the dynamics have been of significant importance for understanding the surface earth systems in general and also for formulating [...] Read more.
Depicting the spatiotemporal dynamics of vegetation cover in the Yellow River Basin (YRB) and delineating the influences of climate change and human activities on the dynamics have been of significant importance for understanding the surface earth systems in general and also for formulating ecological protection plans of the YRB in particular. This study uses the GIMMS NDVI dataset from 1982 to 2015 and the MOD13A1 NDVI dataset from 2000 to 2021 to explore the spatial and temporal characteristics of vegetation cover in the YRB for the period from 1982 to 2021 with an attempt to reveal the influencing factors. The spatial distribution and temporal variation characteristics of vegetation cover are analyzed by maximum value composite, Theil-Sen median trend analysis, and Mann–Kendall test. Combined with the mean annual temperature and annual precipitation in the same period, influencing factors of vegetation cover in the YRB are discussed by using binary linear regression analysis and residual analysis. Results show that: (1) the multi-year average NDVI values increase from the northwest to the southeast and that the annual mean values of the vegetation covers fluctuate relatively greatly along an increasing trend with a growth rate of 0.019/(10a). Understandably, the monthly mean NDVI values show a single-peak distribution pattern, with August being the peak time (0.4936). (2) 77.35% of the studied areas are characterized by exhibiting an increasing trend of vegetation cover during the study period (i.e., 1982–2021). (3) Vegetation cover of the YRB is affected by the combined effects of climate change and human activities, with human activities being more significant in the observed amelioration of vegetation cover. Full article
(This article belongs to the Special Issue Yellow River Basin Management under Pressure: Present State, Restoration and Protection II)
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28 pages, 8423 KiB  
Review
Energy Optimization Techniques in Underwater Internet of Things: Issues, State-of-the-Art, and Future Directions
by Delphin Raj Kesari Mary, Eunbi Ko, Dong Jin Yoon, Soo-Young Shin and Soo-Hyun Park
Water 2022, 14(20), 3240; https://doi.org/10.3390/w14203240 - 14 Oct 2022
Cited by 24 | Viewed by 5851
Abstract
The underwater internet of things (UIoT) has emerged as a booming technology in today’s digital world due to the enhancement of a wide range of underwater applications concerning ocean exploration, deep-sea monitoring, underwater surveillance, diver network monitoring, location and object tracking, etc. Generally, [...] Read more.
The underwater internet of things (UIoT) has emerged as a booming technology in today’s digital world due to the enhancement of a wide range of underwater applications concerning ocean exploration, deep-sea monitoring, underwater surveillance, diver network monitoring, location and object tracking, etc. Generally, acoustic, infrared (IR), visible light (VL), radiofrequency (RF), and magnet induction (MI) are used as the medium of communication in order to transfer information among digitally linked underwater devices. However, each communication medium has its advantages and limitations: for example, the acoustic communication medium is suitable for long-range data transmission but has challenges such as narrow bandwidth, long delay, and high cost, etc., and the optical medium is suitable for short-range data transmission but has challenges such as high attenuation, and optical scattering due to water particles, etc. Furthermore, UIoT devices are operated using batteries with limited capacity and high energy consumption; hence, energy consumption is considered as one of the most significant challenges in UIoT networks. Therefore, to support reliable and energy-efficient communication in UIoT networks, it is necessary to adopt robust energy optimization techniques for UIoT networks. Hence, this paper focuses on identifying the various issues concerning energy optimization in the underwater internet of things and state-of-the-art contributions relevant to inducement techniques of energy optimization in the underwater internet of things; that provides a systematic literature review (SLR) on various power-saving and optimization techniques of UIoT networks since 2010, along with core applications, and research gaps. Finally, future directions are proposed based on the analysis of various energy optimization issues and techniques of UIoT networks. This research contributes much to the profit of researchers and developers to build smart, energy-efficient, auto-rechargeable, and battery-less communication systems for UIoT networks. Full article
(This article belongs to the Special Issue AI and Deep Learning Applications for Water Management)
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16 pages, 1983 KiB  
Review
Constructed Wetlands as a Solution for Sustainable Sanitation: A Comprehensive Review on Integrating Climate Change Resilience and Circular Economy
by Ahmed M. N. Masoud, Amani Alfarra and Sabrina Sorlini
Water 2022, 14(20), 3232; https://doi.org/10.3390/w14203232 - 13 Oct 2022
Cited by 27 | Viewed by 9304
Abstract
About eighty percent of wastewater is discharged into the environment untreated. Many challenges are decelerating solving the global sanitation problem, such as the financial limitations and lack of technical capacities. Parallel to this, many countries are facing a growing demand on their limited [...] Read more.
About eighty percent of wastewater is discharged into the environment untreated. Many challenges are decelerating solving the global sanitation problem, such as the financial limitations and lack of technical capacities. Parallel to this, many countries are facing a growing demand on their limited water resources. Higher water demand and limited availability leads to over-abstraction and deterioration in the availability and quality water resources. In this situation, wastewater can be a new water source. Therefore, there is a growing interest in finding low-cost, easy-to-operate and sustainable sanitation solutions. Constructed wetlands (CWs) in recent years have proved their capability in the sanitation sector as an appropriate sanitation system in different contexts, CWs have proved their ability to treat several types of wastewaters for several decades. Several benefits and facts, such as the low construction and operational costs of CWs, low-energy, and less operational requirements, have raised the interests in CWs as a treatment technology. Several studies have investigated CWs suitability based on different sustainability indices (technical, social, environmental, etc.). In this paper, a comprehensive review covers the definition, types, treatment processes, sustainability criteria, limitations, and challenges of CWs. The paper also focuses on climate change resilience and circular economic approach under the technical and financial criteria, respectively. Full article
(This article belongs to the Special Issue Green Infrastructure as a Technology for Rainwater Retention)
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20 pages, 936 KiB  
Review
Assessing the Role of Water Resources Protection Practice for Sustainable Water Resources Management: A Review
by Koleka Makanda, Stanley Nzama and Thokozani Kanyerere
Water 2022, 14(19), 3153; https://doi.org/10.3390/w14193153 - 7 Oct 2022
Cited by 55 | Viewed by 12664
Abstract
Water resource protection is central to sustainable water supply management for human wellbeing and for the ecological ecosystem to flourish. This review paper focuses on highlighting the role of groundwater and surface water protection practice to improve their sustainable utilization in South Africa. [...] Read more.
Water resource protection is central to sustainable water supply management for human wellbeing and for the ecological ecosystem to flourish. This review paper focuses on highlighting the role of groundwater and surface water protection practice to improve their sustainable utilization in South Africa. Using an integrative approach, this paper initially reflects on the history of water resources utilization, and it examines what is understood by the term “water resources protection”. This review paper then continues by providing an analysis of the current practice at global and local levels. The study found evidence of water resource utilization in the ancient times with limited challenges despite unavailability of regulation mechanisms. However, in recent times water resource availability challenges linked to water availability and water quality deterioration are evident globally despite having policies and regulation in place. Based on the findings of the study, a novel conceptual results-oriented policy monitoring framework is proposed, and it was distinctively designed to address challenges identified in practice in the South African context. The framework is configured on (1) the vision of the catchment protection and sustainable use, (2) water resources protection practices, (3) the state of water resources, and (4) policy evaluation and review processes as the key elements to drive success in policy implementation and monitoring practice. Therefore, this paper provides a foundation for results-oriented policy monitoring for water resources protection to improve sustainable water resources utilization in the country. The proposed framework can be considered as a reference guide that can be used to monitor policy practice for water resources protection by following a result-oriented monitoring approach Full article
(This article belongs to the Special Issue Water Security and Governance in Catchments II)
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27 pages, 1621 KiB  
Review
The Effect Review of Various Biological, Physical and Chemical Methods on the Removal of Antibiotics
by Saikai Huang, Jianping Yu, Cong Li, Qijia Zhu, Yunshu Zhang, Eric Lichtfouse and Nicolas Marmier
Water 2022, 14(19), 3138; https://doi.org/10.3390/w14193138 - 5 Oct 2022
Cited by 50 | Viewed by 8176
Abstract
Antibiotics are highly effective bactericidal drugs that are widely used in human medicine, aquaculture and animal husbandry. Antibiotics enter the aquatic environment through various routes due to low metabolic levels and increased use. Not only are antibiotics inherently toxic, but the spread of [...] Read more.
Antibiotics are highly effective bactericidal drugs that are widely used in human medicine, aquaculture and animal husbandry. Antibiotics enter the aquatic environment through various routes due to low metabolic levels and increased use. Not only are antibiotics inherently toxic, but the spread of potential drug resistance introduced has been identified by the World Health Organization as one of the major threats and risks to global public health security. Therefore, how to efficiently remove antibiotics from water and eliminate the ecological safety hazards caused by antibiotics has been a hot topic in recent years. There are various research methods for decontaminating water with antibiotics. This paper reviews the research and application of various biological, physical, chemical methods and combined processes in antibiotic pollution control. Moreover, this paper describes the degradation mechanism, removal efficiency, influencing factors and technical characteristics of different antibiotics by various methods in detail. Finally, an outlook on future research in antibiotic removal is provided to help promote the development of antibiotic removal technology. Full article
(This article belongs to the Special Issue Soluble Microbial Products and Perfluorinated Compounds in Wastewater Treatment)
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13 pages, 1775 KiB  
Article
The Impact of COVID-19 on Urban Water Consumption in the United States
by Mehdi Nemati and Dat Tran
Water 2022, 14(19), 3096; https://doi.org/10.3390/w14193096 - 1 Oct 2022
Cited by 21 | Viewed by 3488
Abstract
The COVID-19 pandemic has changed how we define “home”, which is recast as the new coffee shop, restaurant, entertainment center, and office during the pandemic. The shift toward working from home led to substantial changes in how consumers behave, affecting the consumption of [...] Read more.
The COVID-19 pandemic has changed how we define “home”, which is recast as the new coffee shop, restaurant, entertainment center, and office during the pandemic. The shift toward working from home led to substantial changes in how consumers behave, affecting the consumption of resources in some cases for years to come. Using data from six water utilities in various states in the U.S., we investigated how water consumption has changed attributable to the implementation of stay-at-home (SAH) orders. The results indicated an overall increase of between 3.08% and 13.65% in daily water consumption during the SAH orders compared to the same period in 2018 and 2019, with the gaps closing as lockdown restrictions eased. The findings also revealed that the changes in water consumption across sectors and user groups were heterogeneous. Specifically, the results showed that total daily residential water demand during SAH orders in 2020 increased significantly, between 11.80% and 13.65%, relative to the same period in 2018 and 2019, but the changes in water consumption for non-residential properties headed in opposite directions with reductions between −22.53% and −45.08%. In addition, we found that the low-income groups did not change their water consumption even with the lockdown. Full article
(This article belongs to the Section Urban Water Management)
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17 pages, 13666 KiB  
Review
Pharmaceutical and Microplastic Pollution before and during the COVID-19 Pandemic in Surface Water, Wastewater, and Groundwater
by Reza Pashaei, Reda Dzingelevičienė, Aida Bradauskaitė, Alireza Lajevardipour, Malgorzata Mlynska-Szultka, Nerijus Dzingelevičius, Saulius Raugelė, Artūras Razbadauskas, Sajjad Abbasi, Robert M. Rees and Boguslaw Buszewski
Water 2022, 14(19), 3082; https://doi.org/10.3390/w14193082 - 30 Sep 2022
Cited by 25 | Viewed by 6322
Abstract
Pharmaceuticals, microplastics, and oil spills are the most hazardous contaminants in aquatic environments. The COVID-19 pandemic enhanced pharmaceutical and microplastic contamination in aquatic environments. The present study aimed to investigate the prevalence of pharmaceutical and microplastic pollution on a global scale. This study [...] Read more.
Pharmaceuticals, microplastics, and oil spills are the most hazardous contaminants in aquatic environments. The COVID-19 pandemic enhanced pharmaceutical and microplastic contamination in aquatic environments. The present study aimed to investigate the prevalence of pharmaceutical and microplastic pollution on a global scale. This study assessed the results of pharmaceutical contamination in 25 countries and microplastic pollution in 13 countries. The findings show that pharmaceutical residues were detected in surface water, groundwater, and wastewater influents and effluents. In total, 43 types of pharmaceutical products were detected in 25 countries. Caffeine, acetaminophen, ibuprofen, sulfamethoxazole, and carbamazepine were the most abundant. In total, 32 types of polymers were detected in 13 countries. In the case of microplastics, polypropylene, polyethylene, polystyrene, and polyethylene terephthalate were the more abundant polymers. Particles with a size of 1–2.5 mm and 2.5–5 mm accounted for half of the microplastics present in 13 countries. This study provides new evidence of the importance of emerging pollutants in aquatic environments before and during the COVID-19 pandemic. Full article
(This article belongs to the Special Issue Micro(nano)plastics in Aquatic Environments: State of the Art and Beyond)
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16 pages, 6815 KiB  
Article
First Evidence of Microplastic Contamination in Antarctic Fish (Actinopterygii, Perciformes)
by Min Zhang, Shigang Liu, Jun Bo, Ronghui Zheng, Fukun Hong, Fulong Gao, Xing Miao, Hai Li and Chao Fang
Water 2022, 14(19), 3070; https://doi.org/10.3390/w14193070 - 29 Sep 2022
Cited by 29 | Viewed by 3907
Abstract
Microplastic (MP) pollution in Antarctica is a hot topic that has gained increasing attention in recent years. However, information regarding MP pollution in Antarctic fishes is currently very limited. The present study provides the first evidence of the occurrence and characteristics of MPs [...] Read more.
Microplastic (MP) pollution in Antarctica is a hot topic that has gained increasing attention in recent years. However, information regarding MP pollution in Antarctic fishes is currently very limited. The present study provides the first evidence of the occurrence and characteristics of MPs in species from five families of the order Perciformes, from the Amundsen Sea (AS) and Ross Sea (RS), Antarctica. MP abundances within the order Perciformes were at a medium level on a global scale, but were higher than those reported in other Antarctic organisms. The detection rate and abundance of MPs in the order Perciformes from the RS (50% and 1.286 items individual−1) were both higher than those from the AS (36% and 1.227 items individual−1). Moreover, the major composition and size of MPs were, respectively, polyacrylamide (PAM) and 100–200 μm in the RS, but rayon and 500–1000 μm in the AS. These differences may be attributed to the different onshore scientific research stations, wastewater treatment facilities, marine activities, ocean currents, and local gyres in the two sea areas. Among the five fish families, members of the Artedidraconidae ingested the smallest MPs and the highest proportion of PAM, which is probably associated with their habitat and degradation effect of unique gut microbiome. The higher hazard index of MPs in fish from the RS is due to the presence of PAM and epoxy resin, which may also have far-reaching health implications for other Antarctic organisms and humans through food web transmission. Overall, long-term monitoring of MP pollution in Antarctic fish and their surrounding marine environment is highly desirable. Full article
(This article belongs to the Special Issue Effects of Micro- and Nano-Plastic Pollution on Marine Ecosystems and Human Health)
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24 pages, 4753 KiB  
Article
Identifying Cost-Effective Low-Impact Development (LID) under Climate Change: A Multi-Objective Optimization Approach
by Yasir Abduljaleel and Yonas Demissie
Water 2022, 14(19), 3017; https://doi.org/10.3390/w14193017 - 25 Sep 2022
Cited by 23 | Viewed by 3910
Abstract
Low-impact development (LID) is increasingly used to reduce stormwater’s quality and quantity impacts associated with climate change and increased urbanization. However, due to the significant variations in their efficiencies and site-specific requirements, an optimal combination of different LIDs is required to benefit from [...] Read more.
Low-impact development (LID) is increasingly used to reduce stormwater’s quality and quantity impacts associated with climate change and increased urbanization. However, due to the significant variations in their efficiencies and site-specific requirements, an optimal combination of different LIDs is required to benefit from their full potential. In this article, the multi-objective genetic algorithm (MOGA) was coupled with the stormwater management model (SWMM) to identify both hydrological and cost-effective LIDs combinations within a large urban watershed. MOGA iteratively optimizes the types, sizes, and locations of different LIDs using a combined cost- and runoff-related objective function under both past and future stormwater conditions. The infiltration trench (IT), rain barrel (RB), rain gardens (RG), bioretention (BR), and permeable pavement were used as potential LIDs since they are common in our study area—the city of Renton, WA, USA. The city is currently adapting different LIDs to mitigate the recent increase in stormwater system failures and flooding. The results from our study showed that the optimum combination of LIDs in the city could reduce the peak flow and total runoff volume by up to 62.25% and 80% for past storms and by13% and 29% for future storms, respectively. The findings and methodologies presented in this study are expected to contribute to the ongoing efforts to improve the performance of large-scale implementations of LIDs. Full article
(This article belongs to the Special Issue Advances in Modeling and Risk Analysis of Floods under Changing Climate)
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22 pages, 6544 KiB  
Review
Contrasting Management and Fates of Two Sister Lakes: Great Salt Lake (USA) and Lake Urmia (Iran)
by Wayne A. Wurtsbaugh and Somayeh Sima
Water 2022, 14(19), 3005; https://doi.org/10.3390/w14193005 - 24 Sep 2022
Cited by 34 | Viewed by 11017
Abstract
Many saline lakes throughout the world are shrinking due to overexploitation of water in their drainage basins. Among them are two of the world’s largest saline lakes, the U.S.A.’s Great Salt Lake, and Iran’s Lake Urmia. Here we provide a comparative analysis of [...] Read more.
Many saline lakes throughout the world are shrinking due to overexploitation of water in their drainage basins. Among them are two of the world’s largest saline lakes, the U.S.A.’s Great Salt Lake, and Iran’s Lake Urmia. Here we provide a comparative analysis of the desiccation of these two lakes that provides insights on management decisions that may help save them and that are relevant to saline lake management worldwide. Great Salt Lake and Lake Urmia were once remarkably similar in size, depth, salinity, and geographic setting. High rates of population growth in both basins have fueled a demand for irrigated agriculture and other uses. In the Great Salt Lake basin, this development began in the late 1800’s and is continuing. The lake’s volume has decreased by 67%, with 75% of the loss driven by water development and 25% by a millennial drought which may portend the start of global climate change impacts. This has greatly increased salinities to 180 g·L−1 stressing the invertebrates in the lake on which birds depend. Only 1% of people in the basin are employed in agriculture; thus, reducing the demand for irrigation development. Population densities in the Urmia basin are double those of the Great Salt Lake basin, and 28% of people are employed in agriculture. These demographics have led to a rapid increase in reservoir construction since 2000 and the subsequent loss of 87% of Lake Urmia’s volume. The water development of Lake Urmia was later, but much faster than that of Great Salt Lake, causing Urmia’s salinity to increase from 190 to over 350 g·L−1 in just 20 years, with subsequent severe ecological decline. Dust storms from the exposed lakebeds of both systems threaten the health of the surrounding populations. To save these lakes and others will require: (1) transparent and collaborative involvement with local interest groups; (2) shifts away from an agricultural-based economy to one based on manufacturing and services; (3) consideration of the diverse ecosystem services of the lakes including mineral extraction, recreation, bird habitats in surrounding wetlands, and dust control. Full article
(This article belongs to the Special Issue Ecosystems of Inland Saline Waters)
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24 pages, 3189 KiB  
Article
Using Deep Learning Algorithms for Intermittent Streamflow Prediction in the Headwaters of the Colorado River, Texas
by Farhang Forghanparast and Ghazal Mohammadi
Water 2022, 14(19), 2972; https://doi.org/10.3390/w14192972 - 22 Sep 2022
Cited by 19 | Viewed by 4516
Abstract
Predicting streamflow in intermittent rivers and ephemeral streams (IRES), particularly those in climate hotspots such as the headwaters of the Colorado River in Texas, is a necessity for all planning and management endeavors associated with these ubiquitous and valuable surface water resources. In [...] Read more.
Predicting streamflow in intermittent rivers and ephemeral streams (IRES), particularly those in climate hotspots such as the headwaters of the Colorado River in Texas, is a necessity for all planning and management endeavors associated with these ubiquitous and valuable surface water resources. In this study, the performance of three deep learning algorithms, namely Convolutional Neural Networks (CNN), Long Short-Term Memory (LSTM), and Self-Attention LSTM models, were evaluated and compared against a baseline Extreme Learning Machine (ELM) model for monthly streamflow prediction in the headwaters of the Texas Colorado River. The predictive performance of the models was assessed over the entire range of flow as well as for capturing the extreme hydrologic events (no-flow events and extreme floods) using a suite of model evaluation metrics. According to the results, the deep learning algorithms, especially the LSTM-based models, outperformed the ELM with respect to all evaluation metrics and offered overall higher accuracy and better stability (more robustness against overfitting). Unlike its deep learning counterparts, the simpler ELM model struggled to capture important components of the IRES flow time-series and failed to offer accurate estimates of the hydrologic extremes. The LSTM model (K.G.E. > 0.7, R2 > 0.75, and r > 0.85), with better evaluation metrics than the ELM and CNN algorithm, and competitive performance to the SA–LSTM model, was identified as an appropriate, effective, and parsimonious streamflow prediction tool for the headwaters of the Colorado River in Texas. Full article
(This article belongs to the Special Issue Artificial Intelligence Techniques in Hydrology and Water Resources Management)
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