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, 2511 KiB  
Review
Review on Drip Irrigation: Impact on Crop Yield, Quality, and Water Productivity in China
by Pei Yang, Lifeng Wu, Minghui Cheng, Junliang Fan, Sien Li, Haidong Wang and Long Qian
Water 2023, 15(9), 1733; https://doi.org/10.3390/w15091733 - 30 Apr 2023
Cited by 15 | Viewed by 18165
Abstract
The scarcity of freshwater resources is a global concern that is exacerbated by an increasing global population and climate change induced by global warming. To address this issue, the largest water-consuming sector has taken a series of measures termed as drip irrigation schemes. [...] Read more.
The scarcity of freshwater resources is a global concern that is exacerbated by an increasing global population and climate change induced by global warming. To address this issue, the largest water-consuming sector has taken a series of measures termed as drip irrigation schemes. The primary purposes of drip irrigation are to reduce water scarcity near the root zone, reduce evaporation, and decrease water use. The application scope of drip irrigation is getting wider and wider, with the number of papers related to drip irrigation increasing year by year from 1990 to 2022. This study reviews crops planted in China that had been irrigated by drip irrigation equipment. The effects of drip irrigation technology on crop growth, physiology, quality, yield, and water use efficiency are summarized. This paper also provides an overview of drip irrigation technology on crop root development and nitrogen uptake. Through a global meta-analysis, it is found that in the case of water shortage, drip irrigation can save water and ensure crop yield compared to flooding irrigation, border irrigation, furrow irrigation, sprinkler irrigation, and micro-sprinkler irrigation. When the drip irrigation amount is more (100–120%), drip irrigation significantly increases crop yields by 28.92%, 14.55%, 8.03%, 2.32%, and 5.17% relative to flooding irrigation, border irrigation, furrow irrigation, sprinkler irrigation, and micro-sprinkler irrigation, respectively. When water resources are sufficient, increasing the amount of drip irrigation also improves crop yield. Moreover, the researchers found that drip irrigation can reduce fertilizer leaching and soil salinity. However, more studies should be conducted in the future to enrich the research on drip irrigation. In conclusion, drip irrigation technology is effective in improving crop growth, water use efficiency, and reducing water scarcity while decreasing fertilizer leaching and soil salinity, making it an ideal solution to the issue of freshwater resource scarcity globally. Full article
(This article belongs to the Special Issue Insight into Drip Irrigation)
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16 pages, 2572 KiB  
Article
Projection of Future Meteorological Droughts in Lake Urmia Basin, Iran
by Babak Ghazi, Sanjana Dutt and Ali Torabi Haghighi
Water 2023, 15(8), 1558; https://doi.org/10.3390/w15081558 - 16 Apr 2023
Cited by 10 | Viewed by 1833
Abstract
Future changes (2015–2100) in precipitation and meteorological droughts in Lake Urmia Basin were investigated using an average mean ensemble of eight general circulation models (GCMs) with high-resolution datasets in socioeconomic pathway scenarios (SSPs) from the Coupled Model Intercomparison Project (CMIP6). In order to [...] Read more.
Future changes (2015–2100) in precipitation and meteorological droughts in Lake Urmia Basin were investigated using an average mean ensemble of eight general circulation models (GCMs) with high-resolution datasets in socioeconomic pathway scenarios (SSPs) from the Coupled Model Intercomparison Project (CMIP6). In order to project the drought, the standardized precipitation index (SPI) was calculated. Overall, the results revealed that precipitation in Lake Urmia Basin will decrease by 3.21% and 7.18% in the SSP1-2.6 and SSP5-8.5 scenarios, respectively. The results based on 6-month-timescale SPI indices projected more “Extremely dry” events in SSP5-8.5 scenarios. The frequency of “Extremely dry” months in SSP5-8.5 compared to SSP1-2.6 is expected to increase by 14, 7, 14, 10, 5, 14, and 7 months for the Mahabad, Maragheh, Saqez, Sarab, Tabriz, Takab, and Urmia stations, respectively. In contrast, the frequency of “Extremely wet” months will decline for all stations in Lake Urmia Basin. The results of this study provide useful insight for considering drought prevention measures to be implemented in advance for Lake Urmia Basin, which is currently experiencing various environmental issues. Full article
(This article belongs to the Special Issue Hydroclimatic Modeling and Monitoring under Climate Change)
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17 pages, 10217 KiB  
Article
Hydrochemical Assessment of the Kisköre Reservoir (Lake Tisza) and the Impacts of Water Quality on Tourism Development
by Tamás Mester, Borbála Benkhard, Mária Vasvári, Péter Csorba, Emőke Kiss, Dániel Balla, István Fazekas, Eduárd Csépes, Ayoub Barkat and György Szabó
Water 2023, 15(8), 1514; https://doi.org/10.3390/w15081514 - 12 Apr 2023
Cited by 6 | Viewed by 1426
Abstract
Outdoor recreation has grown rapidly in recent years, with an increasing preference for areas in good ecological condition. Since lakes represent some of the most important wetlands, providing a wide variety of ecosystem services, they have become a very popular destination. The present [...] Read more.
Outdoor recreation has grown rapidly in recent years, with an increasing preference for areas in good ecological condition. Since lakes represent some of the most important wetlands, providing a wide variety of ecosystem services, they have become a very popular destination. The present study aimed to assess the water quality of the largest artificial lake in Hungary (Kisköre Reservoir—Lake Tisza), and the role of ecological status in tourism development. Monthly water sampling from the basins of the lake (Tiszavalk, Poroszló, Sarud and Abádszalók basins) took place from April–November 2021 and in 2022. The majority of samples from the river section and from the lake are classified as Ca2+-HCO3 type or mixed Ca2+-Na+-HCO3 type. According to the results, the water quality of each basin is considered excellent or good. Rapid warming of the shallow water of the basins was detected during the summer months, resulting in different hydrochemical characteristics (pH, NH4-N, NO2-N, NO3-N, PO4-P, CODcr BOI5) compared to the river section. Differences in the plant nutrient and oxygen balance component groups have been revealed with hierarchical and two-step cluster analysis as well. The results demonstrated that the hydrochemical properties of the lake’s water are substantially influenced by the filling of the lake in spring from the River Tisza and the significant lowering (1.2 m) of the water level in the autumn each year, allowing the drainage of stagnant water, the removal of accumulated sediments and the oxidation of organic matter. The number of tourists on Lake Tisza has increased rapidly over the last decade, confirming that a wide range of ecosystem services have a significant attractive impact on waterfront activities and ecotourism. Full article
(This article belongs to the Special Issue Water Quality Assessment—Methods and Surveys)
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16 pages, 1408 KiB  
Review
Trait-Based Research on Rotifera: The Holy Grail or Just Messy?
by Ulrike Obertegger and Robert Lee Wallace
Water 2023, 15(8), 1459; https://doi.org/10.3390/w15081459 - 08 Apr 2023
Cited by 6 | Viewed by 1824
Abstract
In recent years, trait-based research on plankton has gained interest because of its potential to uncover general roles in ecology. While trait categories for phytoplankton and crustaceans have been posited, rotifer trait assessment has lagged behind. Here, we reviewed the literature to assess [...] Read more.
In recent years, trait-based research on plankton has gained interest because of its potential to uncover general roles in ecology. While trait categories for phytoplankton and crustaceans have been posited, rotifer trait assessment has lagged behind. Here, we reviewed the literature to assess traits key to their life histories and provided a data matrix for the 138 valid genera of phylum Rotifera. We considered seven traits: habitat type, trophi type, presence of lorica and foot, predation defense attributes, corona type, and feeding traits. While most traits were morphological attributes and supposedly easy to assess, we were faced with several challenges regarding trait assignment. Feeding traits were especially difficult to assess for many genera because relevant information was missing. Our assembled trait matrix provides a foundation that will initiate additional research on rotifer functional diversity, diminish the misclassification of rotifer genera into trait categories, and facilitate studies across trophic levels. Full article
(This article belongs to the Special Issue Biodiversity and Functionality of Plankton Communities)
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29 pages, 3870 KiB  
Review
Examining Current and Future Applications of Electrocoagulation in Wastewater Treatment
by Yi Mao, Yaqian Zhao and Sarah Cotterill
Water 2023, 15(8), 1455; https://doi.org/10.3390/w15081455 - 07 Apr 2023
Cited by 14 | Viewed by 7132
Abstract
Electrocoagulation (EC) has gained increasing attention as an effective and environmentally friendly technique for purifying water and wastewater. This review provides a comprehensive analysis of the recent literature on EC and identifies new trends and potentials for further research. Initially, the nature of [...] Read more.
Electrocoagulation (EC) has gained increasing attention as an effective and environmentally friendly technique for purifying water and wastewater. This review provides a comprehensive analysis of the recent literature on EC and identifies new trends and potentials for further research. Initially, the nature of EC and its operating parameters are discussed, while the research trends are analyzed using the Scopus database and VOSviewer software. From 1977 to 2022, 2691 research articles and review papers on EC for water/wastewater treatment were published, with the number of publications increasing from 2 in 1977 to 293 in 2022. In the past five years, most studies focused on treatment performance and the mechanism of EC systems. However, recent emphasis has been placed on combining EC with other treatment processes and addressing emerging pollutants. The innovative applications of EC are highlighted, including the removal of microplastics and per/polyfluoroalkyl substances, the power supply of EC via microbial fuel cells (MFCs) and electro-wetlands (EWs), and the application of power management systems in EC. The review concludes with suggestions for further research to enhance the technology and expand its scope of applications. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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13 pages, 2793 KiB  
Article
The Role of Estuarine Wetlands (Saltmarshes) in Sediment Microplastics Retention
by C. Marisa R. Almeida, Iraide Sáez-Zamacona, Diogo M. Silva, Sabrina M. Rodrigues, Rúben Pereira and Sandra Ramos
Water 2023, 15(7), 1382; https://doi.org/10.3390/w15071382 - 03 Apr 2023
Cited by 8 | Viewed by 1996
Abstract
Concerns regarding plastic pollution, especially microplastics, have increased, as they can be present in different environmental compartments, including estuarine areas and saltmarshes. Although saltmarshes are highly vulnerable to different human activities and pressures, they have the ability to trap/retain contaminants in their vegetated [...] Read more.
Concerns regarding plastic pollution, especially microplastics, have increased, as they can be present in different environmental compartments, including estuarine areas and saltmarshes. Although saltmarshes are highly vulnerable to different human activities and pressures, they have the ability to trap/retain contaminants in their vegetated sediments. However, there is still little information regarding the role of saltmarshes in microplastic retention. Thus, the present study aims to investigate the capability of an estuarine saltmarsh to trap microplastics by comparing microplastic concentrations in vegetated (saltmarsh) and non-vegetated sediments. Microplastic content from sediment (vegetated and non-vegetated) samples collected at different sampling sites in Lima River estuary was estimated using previously optimised extraction protocols, and the observed particles were then characterised accordingly to their size, colour, shape, and polymer (by FTIR). Water samples were also collected and analysed for their microplastics content to complement MPs characterisation within the estuarine area. Microplastics were detected in all sediment samples, with fibres being the most common type of microplastic found, followed by fragments/particles. Overall, vegetated sediments, especially those of saltmarsh species Juncus maritimus, presented a higher number of plastic items. These results indicated that microplastics tend to be trapped in vegetated sediments, supporting the fact that saltmarshes have a significant influence on the transport, distribution, and accumulation of MPs in estuarine areas. Full article
(This article belongs to the Special Issue Microplastics in Wetlands: Occurrence, Fate and Interactions)
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23 pages, 1946 KiB  
Article
Compilation of Water Resource Balance Sheets under Unified Accounting of Water Quantity and Quality, a Case Study of Hubei Province
by Liang Yuan, Liwen Ding, Weijun He, Yang Kong, Thomas Stephen Ramsey, Dagmawi Mulugeta Degefu and Xia Wu
Water 2023, 15(7), 1383; https://doi.org/10.3390/w15071383 - 03 Apr 2023
Cited by 16 | Viewed by 1674
Abstract
This article discusses the issues caused by traditional water resource development and utilization, as well as policy issues in China that have led to a water crisis. The article proposes a theoretical approach along with a quantitative accounting of water resources, in order [...] Read more.
This article discusses the issues caused by traditional water resource development and utilization, as well as policy issues in China that have led to a water crisis. The article proposes a theoretical approach along with a quantitative accounting of water resources, in order to solve these problems. To improve the value accounting method for water resources, the study focuses on a unified accounting perspective of water quantity and quality, allowing for an evaluation of water use efficiency and quality. The study uses prefecture-level cities in Hubei Province as a case study and finds that the water use efficiency of these cities has constantly improved, while water quality has shown an annual improvement. Water resource assets, liabilities, and net assets have increased, but with fluctuations. The study shows differences in water resource assets, liabilities, and net assets in the eastern, central, and western regions of Hubei Province. The unified accounting perspective of water quantity and quality provides a new idea and method for the preparation of water resource balance sheets and will effectively improve the management level and efficiency of water resources. Full article
(This article belongs to the Section Water Resources Management, Policy and Governance)
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21 pages, 711 KiB  
Review
Hydropower Dam Development and Fish Biodiversity in the Mekong River Basin: A Review
by Ian G. Baird and Zeb S. Hogan
Water 2023, 15(7), 1352; https://doi.org/10.3390/w15071352 - 01 Apr 2023
Cited by 7 | Viewed by 4165
Abstract
Over the last few decades, considerable concern has been expressed about the threat of Mekong River Basin hydropower dams to a range of important freshwater riverine fisheries, particularly for fish that seasonally migrate long distances. However, much less attention has been given to [...] Read more.
Over the last few decades, considerable concern has been expressed about the threat of Mekong River Basin hydropower dams to a range of important freshwater riverine fisheries, particularly for fish that seasonally migrate long distances. However, much less attention has been given to the threat of hydropower dams to fish biodiversity in the high-diversity Mekong River Basin, the focus of this paper. Through reviewing the existing state of knowledge regarding Mekong River Basin fish biodiversity, and threats to it, we argue that even though no species are definitively known to have been extirpated from the Mekong River Basin to date, hydropower dam development and various other developments nevertheless pose a serious threat to fish biodiversity. Indeed, dams typically significantly block fish migrations and fish larvae distribution, cause river fragmentation, fundamentally alter river hydrology, and change water quality, all factors that have the potential to intersect with each other and lead to significant species extirpation and extinction, or in some cases, functional extinction, when a small population remains but the important larger population is lost permanently. The circumstances are further exacerbated by the lag time between impact and when that impact becomes evident, cumulative impacts, a lack of consistent data collection, including the collection of base-line data, and insufficient post-project research related to biodiversity. We contend that much more could and should be done to ensure that the Mekong River basin’s exceptional fish biodiversity is not variously diminished and destroyed during the coming years. Full article
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19 pages, 20262 KiB  
Article
A Stacking Ensemble Model of Various Machine Learning Models for Daily Runoff Forecasting
by Mingshen Lu, Qinyao Hou, Shujing Qin, Lihao Zhou, Dong Hua, Xiaoxia Wang and Lei Cheng
Water 2023, 15(7), 1265; https://doi.org/10.3390/w15071265 - 23 Mar 2023
Cited by 18 | Viewed by 5422
Abstract
Improving the accuracy and stability of daily runoff prediction is crucial for effective water resource management and flood control. This study proposed a novel stacking ensemble learning model based on attention mechanism for the daily runoff prediction. The proposed model has a two-layer [...] Read more.
Improving the accuracy and stability of daily runoff prediction is crucial for effective water resource management and flood control. This study proposed a novel stacking ensemble learning model based on attention mechanism for the daily runoff prediction. The proposed model has a two-layer structure with the base model and the meta model. Three machine learning models, namely random forest (RF), adaptive boosting (AdaBoost), and extreme gradient boosting (XGB) are used as the base models. The attention mechanism is used as the meta model to integrate the output of the base model to obtain predictions. The proposed model is applied to predict the daily inflow to Fuchun River Reservoir in the Qiantang River basin. The results show that the proposed model outperforms the base models and other ensemble models in terms of prediction accuracy. Compared with the XGB and weighted averaging ensemble (WAE) models, the proposed model has a 10.22% and 8.54% increase in Nash–Sutcliffe efficiency (NSE), an 18.52% and 16.38% reduction in root mean square error (RMSE), a 28.17% and 18.66% reduction in mean absolute error (MAE), and a 4.54% and 4.19% increase in correlation coefficient (r). The proposed model significantly outperforms the base model and simple stacking model indicated by both the Friedman test and the Nemenyi test. Thus, the proposed model can produce reasonable and accurate prediction of the reservoir inflow, which is of great strategic significance and application value in formulating the rational allocation and optimal operation of water resources and improving the breadth and depth of hydrological forecasting integrated services. Full article
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17 pages, 875 KiB  
Review
The Bacterial Degradation of Lignin—A Review
by Dijana Grgas, Matea Rukavina, Drago Bešlo, Tea Štefanac, Vlado Crnek, Tanja Šikić, Mirna Habuda-Stanić and Tibela Landeka Dragičević
Water 2023, 15(7), 1272; https://doi.org/10.3390/w15071272 - 23 Mar 2023
Cited by 16 | Viewed by 8537
Abstract
Microbial degradation of lignin, a natural complex biopolymer, a renewable raw material with a wide range of applications, has been mainly directed at fungal systems, nevertheless, recent studies have proposed the bacterial role in lignin degradation and modification since bacteria possess remarkable environmental [...] Read more.
Microbial degradation of lignin, a natural complex biopolymer, a renewable raw material with a wide range of applications, has been mainly directed at fungal systems, nevertheless, recent studies have proposed the bacterial role in lignin degradation and modification since bacteria possess remarkable environmental adaptability, and various production of enzymes and biochemistry. An occurrence of a high proportion of lignin-degrading genes has been confirmed in actinobacteria and proteobacteria classes by bioinformatics analysis, which points to the probability of undiscovered pathways and enzymes. Because of that, bacterial lignin decomposition might be substantially different from fungal lignin decomposition. Bacteria capable of lignin modification and degradation belong to actinomycetes, some Firmicutes, α-proteobacteria, and γ-proteobacteria. The enzymes responsible for lignin degradation are lignin peroxidase, manganese-dependent peroxidase, versatile peroxidase, dye-decolourizing peroxidase, and laccases. One of the main lignin producers is the pulp and paper manufacturing industry. Lignolytic microorganisms have been identified from diverse habitats, such as in plants, soil, wood, and the gut. Bacterial strains Bacillus, Rhodococcus, Sterptomyces, and Pseudomonas have been reported to have lignin decomposition ability. This review aims to describe the role of bacteria in lignin degradation, bacterial species, and bacterial enzymes included in lignin degradation. Several reports about bacterial species involved in lignin degradation are also highlighted, and the current state of the knowledge on the degradation of lignin from the pulp and paper manufacturing industry are reported. Full article
(This article belongs to the Special Issue Novel Approaches to Nutrients and Pollutants Removal from Wastewaters)
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23 pages, 1921 KiB  
Review
Biorefinery of Sewage Sludge: Overview of Possible Value-Added Products and Applicable Process Technologies
by Andrea G. Capodaglio
Water 2023, 15(6), 1195; https://doi.org/10.3390/w15061195 - 20 Mar 2023
Cited by 12 | Viewed by 3660
Abstract
The disposal of excess biological sewage sludge from wastewater treatment is a growing environmental issue due to the vast quantities generated worldwide. For many years, sludge disposal has been considered an inevitable “nuisance” linked to the main task of wastewater treatment; recently, the [...] Read more.
The disposal of excess biological sewage sludge from wastewater treatment is a growing environmental issue due to the vast quantities generated worldwide. For many years, sludge disposal has been considered an inevitable “nuisance” linked to the main task of wastewater treatment; recently, the issues relating to the presence of emerging pollutants in sludge have contributed to severe limitations on traditional disposal routes and increased process costs. As a consequence of the water industry’s approach to sustainability and circular economy principles, the investigation into options for sludge-embedded resource recovery has been increasing over time. Among these, the definition of biorefinery encompasses many processes used to process sewage sludge for biofuel and/or resource recovery. In addition to the “conventional” recovery of biogas and nutrients, biopolymers (PHAs and EPS), proteins, enzymes, biopesticides, and biofuels are among the “new” sludge extraction products that are being studied. Not all of the proposed technologies are, however, mature for industrial exploitation as yet. This paper presents an overview of possible product recovery from sludge biorefinery, with emphasis on recent developments, and on the benefits and limitations of applicable technologies for ensuring sustainability and environmental efficiency, through an analysis of the current literature. Full article
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16 pages, 7102 KiB  
Article
Comparative Study for Daily Streamflow Simulation with Different Machine Learning Methods
by Ruonan Hao and Zhixu Bai
Water 2023, 15(6), 1179; https://doi.org/10.3390/w15061179 - 18 Mar 2023
Cited by 12 | Viewed by 1919
Abstract
Rainfall–runoff modeling has been of great importance for flood control and water resource management. However, the selection of hydrological models is challenging to obtain superior simulation performance especially with the rapid development of machine learning techniques. Three models under different categories of machine [...] Read more.
Rainfall–runoff modeling has been of great importance for flood control and water resource management. However, the selection of hydrological models is challenging to obtain superior simulation performance especially with the rapid development of machine learning techniques. Three models under different categories of machine learning methods, including support vector regression (SVR), extreme gradient boosting (XGBoost), and the long-short term memory neural network (LSTM), were assessed for simulating daily runoff over a mountainous river catchment. The performances with different input scenarios were compared. Additionally, the joint multifractal spectra (JMS) method was implemented to evaluate the simulation performances during wet and dry seasons. The results show that: (1) LSTM always obtained a higher accuracy than XGBoost and SVR; (2) the impacts of the input variables were different for different machine learning methods, such as antecedent streamflow for XGBoost and rainfall for LSTM; (3) XGBoost showed a relatively high performance during dry seasons, and the classification of wet and dry seasons improved the simulation performance, especially for LSTM during dry seasons; (4) the JMS analysis indicated the advantages of a hybrid model combined with LSTM trained with wet-season data and XGBoost trained with dry-season data. Full article
(This article belongs to the Special Issue Advances in Streamflow and Flood Forecasting)
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16 pages, 2250 KiB  
Article
Contamination Characteristics and Source Identification of Groundwater in Xishan Coal Mining Area of Taiyuan Based on Hydrochemistry and Sulfur–Oxygen Isotopes
by Di Chen, Qiyan Feng and Min Gong
Water 2023, 15(6), 1169; https://doi.org/10.3390/w15061169 - 17 Mar 2023
Cited by 6 | Viewed by 2124
Abstract
Xishan mining area in Taiyuan is a typical coal industry cluster with a variety of coal-related industrial sites such as coal mines, power plants and coking plants, which seriously pollute the native ecological environment. Study of the hydrochemical characteristics and pollution sources of [...] Read more.
Xishan mining area in Taiyuan is a typical coal industry cluster with a variety of coal-related industrial sites such as coal mines, power plants and coking plants, which seriously pollute the native ecological environment. Study of the hydrochemical characteristics and pollution sources of groundwater in the area can contribute to the ecological protection and remediation of regional groundwater resources. In this study, we collected surface water and groundwater samples from the Xishan mining area and measured and analyzed hydrochemical and sulfur–oxygen isotopes. Results showed that 64.7% of groundwater in the study area exceeded the sulfate standard due to the influence of the coal industry, with some karst groundwater up to 2000 mg/L. In the runoff and discharge area of karst groundwater, the proportion of anthropogenic input of SO42− increased, which led to the hydrochemical type of karst groundwater gradually changing from HCO3-Ca·Mg (recharge area) to SO4-Ca·Mg (discharge area). Results of sulfur–oxygen isotope tests indicated that the δ34SSO4 and δ18OSO4 values of samples were −10.01~24.42‰ and −4.90~12.40‰, respectively, and the sulfur–oxygen isotope values of some karst groundwater were close to the dissolved end of sulfide minerals, indicating their sulfate mainly came from the oxidation of pyrite. Sulfate sources in groundwater water were parsed using IsoSource model. Calculated results revealed that sulfate in pore groundwater mostly originated from pyrite oxidation, and karst groundwater in the recharge area was mainly influenced by atmosphere precipitation, while groundwater in the runoff and discharge areas were significantly affected by pyrite oxidation, accounting for up to 90% in some karst groundwater. Comparing the sulfur–oxygen isotope values of karst groundwater in 1989, 2016 and 2022, we found that the δ34SSO4 values in 2022 decreased significantly, which indicated the expansion of karst groundwater pollution in the Xishan mining area. This study highlights the pollution of regional groundwater by coal-related industrial agglomerations, and the groundwater pollution in the Xishan mining area requires urgent remediation and restoration. Full article
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24 pages, 16191 KiB  
Article
Impacts of Medicanes on Geomorphology and Infrastructure in the Eastern Mediterranean, the Case of Medicane Ianos and the Ionian Islands in Western Greece
by Michalis Diakakis, Spyridon Mavroulis, Christos Filis, Stylianos Lozios, Emmanuel Vassilakis, Giorgos Naoum, Konstantinos Soukis, Aliki Konsolaki, Evelina Kotsi, Dimitra Theodorakatou, Emmanuel Skourtsos, Haralambos Kranis, Marilia Gogou, Nafsika Ioanna Spyrou, Katerina-Navsika Katsetsiadou and Efthymios Lekkas
Water 2023, 15(6), 1026; https://doi.org/10.3390/w15061026 - 08 Mar 2023
Cited by 6 | Viewed by 2052
Abstract
Despite being relatively rare, Mediterranean tropical-like cyclones, also known as Medicanes, induce significant impacts on coastal Mediterranean areas. Under climate change, it is possible that these effects will increase in frequency and severity. Currently, there is only a broad understanding of the types [...] Read more.
Despite being relatively rare, Mediterranean tropical-like cyclones, also known as Medicanes, induce significant impacts on coastal Mediterranean areas. Under climate change, it is possible that these effects will increase in frequency and severity. Currently, there is only a broad understanding of the types and mechanisms of these impacts. This work studied Medicane Ianos (September 2020) and its effects on the Ionian Islands, in Greece, by developing a database of distinct impact elements based on field surveys and public records. Through this archive, the study explored the range of Ianos’ impacts to develop a systematic categorization. Results showed different types of effects induced on the natural and the built environment that can be grouped into 3 categories and 39 sub-categories in inland and coastal areas, indicating an extensive diversity of impacts, ranging from flooding and geomorphic effects to damages in various facilities, vehicles and infrastructure. The systematic description of the typology of Medicanes’ effects presented in this study is a contribution to a better understanding of their consequences as means to improve our ability to prepare for, respond to, and recover from them, a necessary stepping stone in improving the overall preparedness of both the general public and relevant authorities. Full article
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15 pages, 5831 KiB  
Article
Daily Streamflow Forecasts Based on Cascade Long Short-Term Memory (LSTM) Model over the Yangtze River Basin
by Jiayuan Li and Xing Yuan
Water 2023, 15(6), 1019; https://doi.org/10.3390/w15061019 - 07 Mar 2023
Cited by 6 | Viewed by 1773
Abstract
Medium-range streamflow forecasts largely depend on the accuracy of meteorological forecasts. Due to large errors in precipitation forecasts, most streamflow forecasts based on deep learning rely only on historical data. Here, we apply a cascade Long Short-Term Memory (LSTM) model to forecast daily [...] Read more.
Medium-range streamflow forecasts largely depend on the accuracy of meteorological forecasts. Due to large errors in precipitation forecasts, most streamflow forecasts based on deep learning rely only on historical data. Here, we apply a cascade Long Short-Term Memory (LSTM) model to forecast daily streamflow over 49 watersheds in the Yangtze River basin for up to 15 days. The first layer of the cascade LSTM model uses atmospheric circulation factors to predict future precipitation, and the second layer uses forecast precipitation to predict streamflow. The results show that the default LSTM model provides skillful streamflow forecasts over most watersheds. At the lead times of 1, 7, and 15 days, the streamflow Kling–Gupta efficiency (KGE) of 78%, 30%, and 20% watersheds are greater than 0.5, respectively. Its performance improves with the increase in drainage area. After implementing the cascade LSTM model, 61–88% of the watersheds show increased KGE at different leads, and the increase is more obvious at longer leads. Using cascade LSTM with perfect future precipitation shows further improvement, especially over small watersheds. In general, cascade LSTM modeling is a good attempt for streamflow forecasts over the Yangtze River, and it has a potential to connect with dynamical meteorological forecasts. Full article
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19 pages, 1223 KiB  
Review
Tracing COVID-19 Trails in Wastewater: A Systematic Review of SARS-CoV-2 Surveillance with Viral Variants
by Ananda Tiwari, Sangeet Adhikari, Shuxin Zhang, Tamunobelema B. Solomon, Anssi Lipponen, Md. Aminul Islam, Ocean Thakali, Sarawut Sangkham, Mohamed N. F. Shaheen, Guangming Jiang, Eiji Haramoto, Payal Mazumder, Bikash Malla, Manish Kumar, Tarja Pitkänen and Samendra P. Sherchan
Water 2023, 15(6), 1018; https://doi.org/10.3390/w15061018 - 07 Mar 2023
Cited by 11 | Viewed by 9205
Abstract
The emergence of new variants of SARS-CoV-2 associated with varying infectivity, pathogenicity, diagnosis, and effectiveness against treatments challenged the overall management of the COVID-19 pandemic. Wastewater surveillance (WWS), i.e., monitoring COVID-19 infections in communities through detecting viruses in wastewater, was applied to track [...] Read more.
The emergence of new variants of SARS-CoV-2 associated with varying infectivity, pathogenicity, diagnosis, and effectiveness against treatments challenged the overall management of the COVID-19 pandemic. Wastewater surveillance (WWS), i.e., monitoring COVID-19 infections in communities through detecting viruses in wastewater, was applied to track the emergence and spread of SARS-CoV-2 variants globally. However, there is a lack of comprehensive understanding of the use and effectiveness of WWS for new SARS-CoV-2 variants. Here we systematically reviewed published articles reporting monitoring of different SARS-CoV-2 variants in wastewater by following the PRISMA guidelines and provided the current state of the art of this study area. A total of 80 WWS studies were found that reported different monitoring variants of SARS-CoV-2 until November 2022. Most of these studies (66 out of the total 80, 82.5%) were conducted in Europe and North America, i.e., resource-rich countries. There was a high variation in WWS sampling strategy around the world, with composite sampling (50/66 total studies, 76%) as the primary method in resource-rich countries. In contrast, grab sampling was more common (8/14 total studies, 57%) in resource-limited countries. Among detection methods, the reverse transcriptase polymerase chain reaction (RT-PCR)-based sequencing method and quantitative RT-PCR method were commonly used for monitoring SARS-CoV-2 variants in wastewater. Among different variants, the B1.1.7 (Alpha) variant that appeared earlier in the pandemic was the most reported (48/80 total studies), followed by B.1.617.2 (Delta), B.1.351 (Beta), P.1 (Gamma), and others in wastewater. All variants reported in WWS studies followed the same pattern as the clinical reporting within the same timeline, demonstrating that WWS tracked all variants in a timely way when the variants emerged. Thus, wastewater monitoring may be utilized to identify the presence or absence of SARS-CoV-2 and follow the development and transmission of existing and emerging variants. Routine wastewater monitoring is a powerful infectious disease surveillance tool when implemented globally. Full article
(This article belongs to the Special Issue Pathogen Detection and Identification in Wastewater)
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20 pages, 5419 KiB  
Article
Historical Drought Events in the Early Years of Qing Dynasty in Shanxi Based on Hydrological Reconstructions
by Yanping Qu, Xuejun Zhang, Jingyu Zeng, Zhe Li and Juan Lv
Water 2023, 15(5), 995; https://doi.org/10.3390/w15050995 - 06 Mar 2023
Cited by 5 | Viewed by 1856
Abstract
Droughts are serious natural disasters that adversely affect water resources, agriculture, the economy, and the environment. Reconstructing historical drought records is necessary to assess the impact of droughts and their evolution and has become a top priority to support and improve sustainable water [...] Read more.
Droughts are serious natural disasters that adversely affect water resources, agriculture, the economy, and the environment. Reconstructing historical drought records is necessary to assess the impact of droughts and their evolution and has become a top priority to support and improve sustainable water management decisions. In this study, we used Shanxi Province as the research area, and meteorological data from the early years of Guangxu in the Qing Dynasty were reconstructed using historical rain and snow records. The Variable Infiltration Capacity (VIC) model is driven by the reconstruction of historical meteorological data. The study area’s monthly runoff and soil water sequence from 1875 to 1879 were simulated, and the hydrology and soil of the ancient historical period were reproduced in the absence of data. The results show the following: (1) The idea of reconstructing hydrological parameters using historical data is feasible and the VIC model can be used to study drought characteristics under specific scenarios. (2) The proportions of areas with runoff depths less than 10 mm throughout Shanxi from 1875 to 1879 were 55%, 48%, 58%, 19%, and 30%. The annual runoff depth in each region from 1875 to 1877 was less than 60 mm. The hydrological drought from 1875 to 1877 was very serious, and the area covered by the drought was relatively large. (3) The annual average soil water content of various regions was stable between 150 and 510 mm from 1875 to 1879. The soil water content had no apparent interannual variation. The area with soil water content less than 180 mm accounted for ratios as high as 31%. This research provides new ideas for ancient drought research and a scientific basis for regional drought prevention, mitigation, and water resources management, and ensures the orderly progress of agricultural production activities. Full article
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25 pages, 1568 KiB  
Review
Impact of Antibiotic Pollution on the Bacterial Population within Surface Water with Special Focus on Mountain Rivers
by Klaudia Kulik, Anna Lenart-Boroń and Kinga Wyrzykowska
Water 2023, 15(5), 975; https://doi.org/10.3390/w15050975 - 03 Mar 2023
Cited by 20 | Viewed by 9128
Abstract
Environmental aquatic pollution with antibiotics is a global challenge that affects even pristine mountain environments. Monitoring the concentration of antibiotics in water is critical to water resource management. In this review, we present the sources and degradation routes of antibiotics polluting surface waters, [...] Read more.
Environmental aquatic pollution with antibiotics is a global challenge that affects even pristine mountain environments. Monitoring the concentration of antibiotics in water is critical to water resource management. In this review, we present the sources and degradation routes of antibiotics polluting surface waters, with particular focus on mountain environments and pristine areas. This pollution is strongly related to anthropopressure resulting from intensive tourism. An important aspect of the threat to the environment is water containing antibiotics at sub-inhibitory concentrations, which affects bacterial populations. Antibiotics are ecological factors driving microbial evolution by changing the bacterial community composition, inhibiting or promoting their ecological functions, and enriching and maintaining drug resistance. We paid attention to the stability of antibiotics and their half-lives in water related to biotic and abiotic degradation, which results from the structures of molecules and environmental conditions. Wastewater treatment combined with advanced treatment techniques significantly increase the efficiency of antibiotic removal from wastewater. Modern methods of wastewater treatment are crucial in reducing the supply of antibiotics to aquatic environments and enhancing the possibility of economic and safe reuse of wastewater for technical purposes. We provide a perspective on current research investigating antibiotic emergence in mountain areas and identify knowledge gaps in this field. Full article
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50 pages, 1699 KiB  
Review
A Review of the Application of the Soil and Water Assessment Tool (SWAT) in Karst Watersheds
by Ibrahim Al Khoury, Laurie Boithias and David Labat
Water 2023, 15(5), 954; https://doi.org/10.3390/w15050954 - 01 Mar 2023
Cited by 10 | Viewed by 9938
Abstract
Karst water resources represent a primary source of freshwater supply, accounting for nearly 25% of the global population water needs. Karst aquifers have complex recharge characteristics, storage patterns, and flow dynamics. They also face a looming stress of depletion and quality degradation due [...] Read more.
Karst water resources represent a primary source of freshwater supply, accounting for nearly 25% of the global population water needs. Karst aquifers have complex recharge characteristics, storage patterns, and flow dynamics. They also face a looming stress of depletion and quality degradation due to natural and anthropogenic pressures. This prompted hydrogeologists to apply innovative numerical approaches to better understand the functioning of karst watersheds and support karst water resources management. The Soil and Water Assessment Tool (SWAT) is a semi-distributed hydrological model that has been used to simulate flow and water pollutant transport, among other applications, in basins including karst watersheds. Its source code has also been modified by adding distinctive karst features and subsurface hydrology models to more accurately represent the karst aquifer discharge components. This review summarizes and discusses the findings of 75 SWAT-based studies in watersheds that are at least partially characterized by karst geology, with a primary focus on the hydrological assessment in modified SWAT models. Different karst processes were successfully implemented in SWAT, including the recharge in the epikarst, flows of the conduit and matrix systems, interbasin groundwater flow, and allogenic recharge from sinkholes and sinking streams. Nonetheless, additional improvements to the existing SWAT codes are still needed to better reproduce the heterogeneity and non-linearity of karst flow and storage mechanisms in future research. Full article
(This article belongs to the Special Issue Hydrogeology and Geochemistry of Karst Aquifers)
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27 pages, 5225 KiB  
Article
Streamflow Estimation in a Mediterranean Watershed Using Neural Network Models: A Detailed Description of the Implementation and Optimization
by Ana Ramos Oliveira, Tiago Brito Ramos and Ramiro Neves
Water 2023, 15(5), 947; https://doi.org/10.3390/w15050947 - 01 Mar 2023
Cited by 6 | Viewed by 1791
Abstract
This study compares the performance of three different neural network models to estimate daily streamflow in a watershed under a natural flow regime. Based on existing and public tools, different types of NN models were developed, namely, multi-layer perceptron, long short-term memory, and [...] Read more.
This study compares the performance of three different neural network models to estimate daily streamflow in a watershed under a natural flow regime. Based on existing and public tools, different types of NN models were developed, namely, multi-layer perceptron, long short-term memory, and convolutional neural network. Precipitation was either considered an input variable on its own or combined with air temperature as another input variable. Different periods of accumulation, average, and/or delay were considered. The models’ structures were optimized and automatically showed that CNN performed best, reaching, for example, a Nash–Sutcliffe efficiency of 0.86 and a root mean square error of 4.2 m3 s−1. This solution considers a 1D convolutional layer and a dense layer as the input and output layers, respectively. Between those layers, two 1D convolutional layers are considered. As input variables, the best performance was reached when the accumulated precipitation values were 1 to 5, and 10 days and delayed by 1 to 7 days. Full article
(This article belongs to the Section Hydrology)
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17 pages, 6467 KiB  
Article
Investigation of Hillslope Vineyard Soil Water Dynamics Using Field Measurements and Numerical Modeling
by Vedran Krevh, Jannis Groh, Lutz Weihermüller, Lana Filipović, Jasmina Defterdarović, Zoran Kovač, Ivan Magdić, Boris Lazarević, Thomas Baumgartl and Vilim Filipović
Water 2023, 15(4), 820; https://doi.org/10.3390/w15040820 - 20 Feb 2023
Cited by 3 | Viewed by 2140
Abstract
Soil heterogeneities can impact hillslope hydropedological processes (e.g., portioning between infiltration and runoff), creating a need for in-depth knowledge of processes governing water dynamics and redistribution. The presented study was conducted at the SUPREHILL Critical Zone Observatory (CZO) (hillslope vineyard) in 2021. A [...] Read more.
Soil heterogeneities can impact hillslope hydropedological processes (e.g., portioning between infiltration and runoff), creating a need for in-depth knowledge of processes governing water dynamics and redistribution. The presented study was conducted at the SUPREHILL Critical Zone Observatory (CZO) (hillslope vineyard) in 2021. A combination of field investigation (soil sampling and monitoring campaign) and numerical modeling with hydrological simulator HYDRUS-1D was used to explore the water dynamics in conjunction with data from a sensor network (soil water content (SWC) and soil-water potential (SWP) sensors), along the hillslope (hilltop, backslope, and footslope). Soil hydraulic properties (SHP) were estimated based on (i) pedotransfer functions (PTFs), (ii) undisturbed soil cores, and (iii) sensor network data, and tested in HYDRUS. Additionally, a model ensemble mean from HYDRUS simulations was calculated with PTFs. The highest agreement of simulated with observed SWC for 40 cm soil depth was found with the combination of laboratory and field data, with the lowest average MAE, RMSE and MAPE (0.02, 0.02, and 5.34%, respectively), and highest average R2 (0.93), while at 80 cm soil depth, PTF model ensemble performed better (MAE = 0.03, RMSE = 0.03, MAPE = 7.55%, R2 = 0.81) than other datasets. Field observations indicated that heterogeneity and spatial variability regarding soil parameters were present at the site. Over the hillslope, SWC acted in a heterogeneous manner, which was most pronounced during soil rewetting. Model results suggested that the incorporation of field data expands model performance and that the PTF model ensemble is a feasible option in the absence of laboratory data. Full article
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18 pages, 2432 KiB  
Article
The Influence of Circular Economy and 4IR Technologies on the Climate–Water–Energy–Food Nexus and the SDGs
by Mohamed Sameer Hoosain, Babu Sena Paul, Wesley Doorsamy and Seeram Ramakrishna
Water 2023, 15(4), 787; https://doi.org/10.3390/w15040787 - 17 Feb 2023
Cited by 7 | Viewed by 3529
Abstract
The United Nations Member States created a common roadmap for sustainability and development in 2015. The UN-SDGs are included in the 2030 Plan as an immediate call to action from all nations in the form of global partnerships. To date, a handful of [...] Read more.
The United Nations Member States created a common roadmap for sustainability and development in 2015. The UN-SDGs are included in the 2030 Plan as an immediate call to action from all nations in the form of global partnerships. To date, a handful of countries have achieved substantial progress toward the targets. The climate–water–energy–food nexus is being advocated as a conceptual method for achieving sustainable development. According to research, frameworks for adopting nexus thinking have not been the best solution to clearly or sufficiently include thoughts on sustainability. Therefore, there is much room for other solutions; these are in the form of newer Fourth Industrial Revolution digital technologies, as well as transitioning from a linear economy to a circular economy. In this paper, we come to understand these two models and their linkages between climate, water, energy, and food; their application and challenges, and, finally, the effects on the UN-SDGs. It was found that both circular economy and newer Fourth Industrial Revolution digital technologies can positively support the nexus as well as directly address the UN-SDGs, specifically SDGs 7, 8, 9, 11, 12, and 13. Full article
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19 pages, 3717 KiB  
Article
Effect of Sand Co-Presence on CrVI Removal in Fe0-H2O System
by Marius Gheju and Ionel Balcu
Water 2023, 15(4), 777; https://doi.org/10.3390/w15040777 - 16 Feb 2023
Cited by 6 | Viewed by 1743
Abstract
The aim of the present study was to provide new knowledge regarding the effect of non-expansive inert material addition on anionic pollutant removal efficiency in Fe0-H2O system. Non-disturbed batch experiments and continuous-flow-through column tests were conducted using CrVI [...] Read more.
The aim of the present study was to provide new knowledge regarding the effect of non-expansive inert material addition on anionic pollutant removal efficiency in Fe0-H2O system. Non-disturbed batch experiments and continuous-flow-through column tests were conducted using CrVI as a redox–active contaminant in three different systems: “Fe0 + sand”, “Fe0 only” and ”sand only”. Both experimental procedures have the advantage that formation of (hydr)oxide layers on Fe0 is not altered, which makes them appropriate proxies for real Fe0-based filter technologies. Batch experiments carried out at pH 6.5 showed a slight improvement of CrVI removal in a 20% Fe0 system, compared to 50, 80 and 100% Fe0 systems. Column tests conducted at pH 6.5 supported results of batch experiments, revealing highest CrVI removal efficiencies for “Fe0 + sand” systems with lowest Fe0 ratio. However, the positive effect of sand co-presence decreases with increasing pH from 6.5 to 7.1. Scanning electron microscopy—energy dispersive angle X-ray spectrometry and X-ray diffraction spectroscopy employed for the characterization of Fe0 before and after experiments indicated that the higher the volumetric ratio of sand in “Fe0 + sand” system, the more intense the corrosion processes affecting the Fe0 grains. Results presented herein indicate the capacity of sand at sustaining the efficiency of CrVI removal in Fe0-H2O system. The outcomes of the present study suggest that a volumetric ratio Fe0:sand = 1:3 could assure not only the long-term permeability of Fe0-based filters, but also enhanced removal efficiency of CrVI from contaminated water. Full article
(This article belongs to the Special Issue Sustainable Remediation Using Metallic Iron: Quo Vadis?)
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14 pages, 3319 KiB  
Article
Used Filter Cartridges as Potential Adsorbents of Organic Pollutants
by Martyna Szymańska and Piotr Nowicki
Water 2023, 15(4), 714; https://doi.org/10.3390/w15040714 - 11 Feb 2023
Cited by 3 | Viewed by 1801
Abstract
The main objective of this study was to assess the usefulness of exhausted activated carbon-based filter cartridges for the removal of organic pollutants from aqueous solutions using the example of two model pollutants: synthetic dyes with different particle sizes, i.e., methylene blue (MB) [...] Read more.
The main objective of this study was to assess the usefulness of exhausted activated carbon-based filter cartridges for the removal of organic pollutants from aqueous solutions using the example of two model pollutants: synthetic dyes with different particle sizes, i.e., methylene blue (MB) and malachite green (MG). In order to determine the organic dyes’ adsorption mechanism, the effects of phase contact time, initial dye concentration, pH, and temperature of the system were investigated. Langmuir and Freundlich isotherm models were employed to analyze the experimental data. Additionally, all adsorbents were characterized in terms of the ash content, type of porous structure, presence of surface functional groups, pH value, and iodine adsorption number—which is one of the quality control parameters of activated carbons. Adsorption tests have shown that carbonaceous materials from bottle filters and filter jugs can be successfully used for the removal of organic dyes from the liquid phase. The maximum sorption capacity of this type of adsorbent towards methylene blue was 333.06 mg/g, while in the case of malachite green it was 308.75 mg/g. For all carbonaceous materials, a better fit to the experimental data was achieved with a Langmuir isotherm than a Freundlich one. It has also been shown that the efficiency of MB and MG adsorption from aqueous solutions decreases with increasing temperature of the system—the best results were obtained at 25 °C. A better fit of the kinetics data was achieved using the pseudo-second order model. Full article
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20 pages, 1327 KiB  
Review
Full-Scale Sewage Sludge Reduction Technologies: A Review with a Focus on Energy Consumption
by Roberta Ferrentino, Michela Langone, Luca Fiori and Gianni Andreottola
Water 2023, 15(4), 615; https://doi.org/10.3390/w15040615 - 04 Feb 2023
Cited by 21 | Viewed by 7603
Abstract
In recent years, increasing attention has been paid to the problem of sewage sludge management and the relevant energy consumption, which represent the main cost items in wastewater treatment plants. Therefore, implementation of technologies that can reduce sludge production and ensure a positive [...] Read more.
In recent years, increasing attention has been paid to the problem of sewage sludge management and the relevant energy consumption, which represent the main cost items in wastewater treatment plants. Therefore, implementation of technologies that can reduce sludge production and ensure a positive impact on the energy of the entire sewage treatment plant has gained considerable importance in the scientific and technical community. The objective of this study was thus to screen full-scale sludge reduction technologies integrated into both the water line and the sludge line of a municipal sewage treatment plant with a sustainable impact on the overall balance of the plant. The results showed that, within the water line, ultrasound in the recirculation line of the activated sludge allowed for greater reductions in sludge production than the Cannibal and UTN systems, despite the higher energy consumption. CAMBITM, BioThelysTM, ExelysTM and TurboTec® enabled the greatest reductions in sludge production among the technologies integrated into the sludge line, and although they required a large amount of energy, this was partially offset by energy recovery in terms of additional biogas production. Full article
(This article belongs to the Special Issue Sewage Sludge: Treatment and Recovery)
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13 pages, 748 KiB  
Article
Euryhalinity and Geographical Origin Aid Global Alien Crayfish Invasions
by Aldona Dobrzycka-Krahel and Maria Leonor Fidalgo
Water 2023, 15(3), 569; https://doi.org/10.3390/w15030569 - 01 Feb 2023
Cited by 4 | Viewed by 2392
Abstract
Salinity tolerance is a determinant of a narrow or wide distribution range of organisms. Crayfishes are important key species in many aquatic environments so require a better understanding of their ability to live in different saline regimes. We identified all alien crayfish and [...] Read more.
Salinity tolerance is a determinant of a narrow or wide distribution range of organisms. Crayfishes are important key species in many aquatic environments so require a better understanding of their ability to live in different saline regimes. We identified all alien crayfish and examined their habitats (freshwater and/or saline) and origins to test whether these factors predict their dispersal. We used contingency tables populated with raw frequency data with χ2—tests and assessed statistical significance at α of 0.05. We identified 21 alien crayfishes and we found that alien crayfish species were disproportionately freshwater (71%), with significantly lower proportions of euryhaline crayfishes inhabiting freshwater to saline environments (29%). Alien crayfishes also significantly disproportionally originate from America (67% of these taxa) when compared to all ‘other’ grouped regions (33%). In total, 36% of American crayfishes represent euryhaline species inhabiting freshwater to saline habitats against only 14% of crayfishes from all “other” grouped regions. This suggests that binomial euryhalinity/origin can help understand the potential of spread. We discussed obtained results with known experimental data on salinity tolerance, osmoregulation, growth, and reproduction of American alien crayfish. The paper will help in the management of crayfish spread. Full article
(This article belongs to the Special Issue Aquatic Ecosystem: Problems and Benefits)
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31 pages, 1951 KiB  
Article
Contaminant Back Diffusion from Low-Conductivity Matrices: Case Studies of Remedial Strategies
by Julie Blue, Thomas Boving, Mary Ellen Tuccillo, Jonathan Koplos, Jason Rose, Michael Brooks and David Burden
Water 2023, 15(3), 570; https://doi.org/10.3390/w15030570 - 01 Feb 2023
Cited by 3 | Viewed by 2717
Abstract
Recalcitrant groundwater contamination is a common problem at hazardous waste sites worldwide. Groundwater contamination persists despite decades of remediation efforts at many sites because contaminants sorbed or dissolved within low-conductivity zones can back diffuse into high-conductivity zones, and therefore act as a continuing [...] Read more.
Recalcitrant groundwater contamination is a common problem at hazardous waste sites worldwide. Groundwater contamination persists despite decades of remediation efforts at many sites because contaminants sorbed or dissolved within low-conductivity zones can back diffuse into high-conductivity zones, and therefore act as a continuing source of contamination to flowing groundwater. A review of the available literature on remediation of plume persistence due to back diffusion was conducted, and four sites were selected as case studies. Remediation at the sites included pump and treat, enhanced bioremediation, and thermal treatment. Our review highlights that a relatively small number of sites have been studied in sufficient detail to fully evaluate remediation of back diffusion; however, three general conclusions can be made based on the review. First, it is difficult to assess the significance of back diffusion without sufficient data to distinguish between multiple factors contributing to contaminant rebound and plume persistence. Second, high-resolution vertical samples are decidedly valuable for back diffusion assessment but are generally lacking in post-treatment assessments. Third, complete contaminant mass removal from back diffusion sources may not always be possible. Partial contaminant mass removal may nonetheless have potential benefits, similar to partial mass removal from primary DNAPL source zones. Full article
(This article belongs to the Special Issue Diffusion Processes in Water Pollution and Remediation)
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16 pages, 5014 KiB  
Article
Investigating Climate Change Effects on Evapotranspiration and Groundwater Recharge of the Nile Delta Aquifer, Egypt
by Mohamed Galal Eltarabily, Ismail Abd-Elaty, Ahmed Elbeltagi, Martina Zeleňáková and Ismail Fathy
Water 2023, 15(3), 572; https://doi.org/10.3390/w15030572 - 01 Feb 2023
Cited by 4 | Viewed by 3332
Abstract
Climate change (CC) directly affects crops’ growth stages or level of maturity, solar radiation, humidity, temperature, and wind speed, and thus crop evapotranspiration (ETc). Increased crop ETc shifts the fraction of discharge from groundwater aquifers, while long-term shifts in [...] Read more.
Climate change (CC) directly affects crops’ growth stages or level of maturity, solar radiation, humidity, temperature, and wind speed, and thus crop evapotranspiration (ETc). Increased crop ETc shifts the fraction of discharge from groundwater aquifers, while long-term shifts in discharge can change the groundwater level and, subsequently, aquifer storage. The long-term effect of CC on the groundwater flow under different values of ETc was assessed for the Nile Delta aquifer (NDA) in Egypt. To quantify such impacts, numerical modeling using MODFLOW was set up to simulate the groundwater flow and differences in groundwater levels in the long term in the years 2030, 2050, and 2070. The model was initially calibrated against the hydraulic conductivity of the aquifer layers of the groundwater levels in the year 2008 from 60 observation wells throughout the study area. Then, it was validated with the current groundwater levels using an independent set of data (23 points), obtaining a very good agreement between the calculated and observed heads. The results showed that the combination of solar radiation, vapor pressure deficit, and humidity (H) are the best variables for predicting ETc in Nile Delta zones (north, middle, and south). ETc among the whole Nile Delta will increase by 11.2, 15.0, and 19.0% for the years 2030, 2050, and 2070, respectively. Zone budget analysis revealed that the increase of ETc will decrease the inflow and the groundwater head difference (GWHD). Recharge of the aquifer will be decreased by 19.74, 27.16, and 36.84% in 2030, 2050, and 2070, respectively. The GWHD will record 0.95 m, 1.05 m, and 1.40 m in 2030, 2050, and 2070, respectively when considering the increase of ETc. This reduction will lead to a slight decline in the storage of the Nile Delta groundwater aquifer. Our findings support the decision of the designers and the policymakers to guarantee a long-term sustainable management plan of the groundwater for the NDA and deltas with similar climate conditions. Full article
(This article belongs to the Special Issue Assessment and Management of Hydrological Risks Due to Climate Change)
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21 pages, 1245 KiB  
Review
A Review of Hydrodynamic and Machine Learning Approaches for Flood Inundation Modeling
by Fazlul Karim, Mohammed Ali Armin, David Ahmedt-Aristizabal, Lachlan Tychsen-Smith and Lars Petersson
Water 2023, 15(3), 566; https://doi.org/10.3390/w15030566 - 01 Feb 2023
Cited by 23 | Viewed by 5874
Abstract
Machine learning (also called data-driven) methods have become popular in modeling flood inundations across river basins. Among data-driven methods, traditional machine learning (ML) approaches are widely used to model flood events, and recently deep learning (DL) approaches have gained more attention across the [...] Read more.
Machine learning (also called data-driven) methods have become popular in modeling flood inundations across river basins. Among data-driven methods, traditional machine learning (ML) approaches are widely used to model flood events, and recently deep learning (DL) approaches have gained more attention across the world. In this paper, we reviewed recently published literature on ML and DL applications for flood modeling for various hydrologic and catchment characteristics. Our extensive literature review shows that DL models produce better accuracy compared to traditional approaches. Unlike physically based models, ML/DL models suffer from the lack of using expert knowledge in modeling flood events. Apart from challenges in implementing a uniform modeling approach across river basins, the lack of benchmark data to evaluate model performance is a limiting factor for developing efficient ML/DL models for flood inundation modeling. Full article
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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 11 | Viewed by 3839
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
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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 16 | Viewed by 2401
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
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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 10 | Viewed by 2291
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
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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 13 | Viewed by 7940
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 11 | Viewed by 2508
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
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11 pages, 2275 KiB  
Article
Rainfall Threshold for Shallow Landslide Triggering Due to Rising Water Table
by Antonello Troncone, Luigi Pugliese and Enrico Conte
Water 2022, 14(19), 2966; https://doi.org/10.3390/w14192966 - 21 Sep 2022
Cited by 13 | Viewed by 1884
Abstract
In the present study, a simple-to-use method is proposed for a preliminary prediction of the occurrence of shallow landslides (generally, with a thickness of 1–2 m) due to rainfall. This method can be used when a water table forms within the slope or [...] Read more.
In the present study, a simple-to-use method is proposed for a preliminary prediction of the occurrence of shallow landslides (generally, with a thickness of 1–2 m) due to rainfall. This method can be used when a water table forms within the slope or the existing groundwater level rises due to rain infiltration, resulting in an increase in the pore water pressure. A relationship is also provided to establish when these conditions occur and the method can consequently be used. The proposed method combines a simplified solution to evaluate the change in pore water pressure within the slope due to infiltration, with the simple scheme of infinite slope to calculate a critical value of the pore water pressure that determines the incipient failure condition of the slope. In this way, a threshold curve can be also determined to readily assess whether a rainfall event with expected intensity and duration is capable of causing a slope failure at a given depth, where the initial pore water pressure is known. The method is completely analytical and only requires a few parameters as input data, which in addition can be obtained from conventional tests. A well-documented case study is considered to show how the method can be used for routine applications. Full article
(This article belongs to the Special Issue Susceptibility Assessment of Rainfall-Induced Landslides)
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23 pages, 8041 KiB  
Article
Flood-Frequency Analysis for Dams in Romania
by Cornel Ilinca and Cristian Gabriel Anghel
Water 2022, 14(18), 2884; https://doi.org/10.3390/w14182884 - 15 Sep 2022
Cited by 9 | Viewed by 4695
Abstract
Accurately determining the maximum designed water discharges of dams is extremely important, considering the economic costs of carrying out these types of hydrotechnical works and the possible disastrous consequences resulting from their incorrect design. This article describes and applies probability distributions used in [...] Read more.
Accurately determining the maximum designed water discharges of dams is extremely important, considering the economic costs of carrying out these types of hydrotechnical works and the possible disastrous consequences resulting from their incorrect design. This article describes and applies probability distributions used in hydrology, with some recommended by Romanian legislation standard NP 129-2011. The methods for estimating the parameters presented in this article, as well as the establishment of directions for correlating the normative with international regulations, resulting from the research on many rivers with different characteristics, conducted within the Faculty of Hydrotechnics, were completed with specialized computer applications for applying the normative. In this article, two case studies reflecting this research are presented. The verification of the proposed recommendations, on rivers with hydrographic basins with different physiographic characteristics, confirmed the opportunity to implement rigorous and simple criteria. The presentation of the quantile form of some distributions (especially Pearson III) and of the expressions of moments (central and raw) of high order, as well as the presentation of the frequency factors of each analyzed distribution necessary to calculate the confidence interval, constitute novelties, thus facilitating the ease of use of these distributions. Full article
(This article belongs to the Section Hydrology)
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15 pages, 2472 KiB  
Article
The Effect and Influence Mechanism of Soil Salinity on Phosphorus Availability in Coastal Salt-Affected Soils
by Wenping Xie, Jingsong Yang, Shan Gao, Rongjiang Yao and Xiangping Wang
Water 2022, 14(18), 2804; https://doi.org/10.3390/w14182804 - 09 Sep 2022
Cited by 19 | Viewed by 3327
Abstract
Soil salinization is a problem that arouses the world’s attention. Soil salinity is an important limitation for agriculture production in coastal area. Phosphorus is a very important nutrient element in the process of plant growth, and its effectiveness affects plant growth to a [...] Read more.
Soil salinization is a problem that arouses the world’s attention. Soil salinity is an important limitation for agriculture production in coastal area. Phosphorus is a very important nutrient element in the process of plant growth, and its effectiveness affects plant growth to a great extent. In this study, soil available phosphorus and its component in Hedley phosphorus classification were found to be affected by soil salinity in coastal areas of Jiangsu Province. Several key environmental factors changed under the saline environment of the coastal areas, such as soil salinity, soil pH, and soil alkaline phosphatase activity. These environmental factors were significantly correlated with soil available phosphorus. Results showed that there were significant correlations between soil salinity and other environmental factors, and soil salinity and alkaline phosphatase activity were the main influencing factors of soil available phosphorus in this study. Significant positive correlation was found between alkaline phosphatase activity and soil salt content, and soil salinity was considered as the most important impact factor for soil available phosphorus as it affected the surrounding environment, and the soil alkaline phosphatase could be considered as the direct influencing factor for soil available phosphorus. Analysis between the soil alkaline phosphatase activity and phosphorus component showed that soil alkaline phosphatase activity could increase the proportion of active inorganic phosphorus and medium active inorganic phosphorus in soil phosphorus pool, which explained the effect of soil alkaline phosphatase activity on soil available phosphorus. Full article
(This article belongs to the Special Issue Monitoring, Reclamation and Management of Salt-Affected Lands)
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14 pages, 2822 KiB  
Article
Analyzing the Impacts of Sewer Type and Spatial Distribution of LID Facilities on Urban Runoff and Non-Point Source Pollution Using the Storm Water Management Model (SWMM)
by Jimin Lee, Jinsun Kim, Jong Mun Lee, Hee Seon Jang, Minji Park, Joong Hyuk Min and Eun Hye Na
Water 2022, 14(18), 2776; https://doi.org/10.3390/w14182776 - 06 Sep 2022
Cited by 9 | Viewed by 2043
Abstract
The negative changes in the hydrological cycle are increasing due to climate change and urbanization, resulting in deterioration of water quality and environmental issues. Although Low-Impact Development (LID) techniques studies have been conducted to solve this problem, the spatial distribution of LID facilities [...] Read more.
The negative changes in the hydrological cycle are increasing due to climate change and urbanization, resulting in deterioration of water quality and environmental issues. Although Low-Impact Development (LID) techniques studies have been conducted to solve this problem, the spatial distribution of LID facilities and sewer types has received less attention. In this study, it is proposed to analyze the effects of sewer type, the spatial distribution of LID facilities, and LID type on runoff and water quality using the Storm Water Management Model and to identify effective ways of improving the hydrological cycle and Non-Point Source (NPS) pollution associated with urbanization. As a result of the runoff reduction analysis, 68% of the rainfall was discharged at the outlet for separate sewers, 79% for combined sewers without storage tank, and 49% for combined sewers with storage tank. The LID scenario results showed the distributed LID application method has higher reduction efficiency of runoff and NPS pollution than the intensive application method. Moreover, intensive application of LID in downstream areas resulted in higher runoff reduction efficiency than the application of LID in upstream areas. It will be used not only in the hydrological cycle plan but also in NPS pollution management. Full article
(This article belongs to the Special Issue Stormwater Management in Urban and Rural Areas)
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17 pages, 2738 KiB  
Article
Crop Water Deficit and Supplemental Irrigation Requirements for Potato Production in a Temperate Humid Region (Prince Edward Island, Canada)
by Serban Danielescu, Kerry T. B. MacQuarrie, Bernie Zebarth, Judith Nyiraneza, Mark Grimmett and Mona Levesque
Water 2022, 14(17), 2748; https://doi.org/10.3390/w14172748 - 03 Sep 2022
Cited by 8 | Viewed by 2282
Abstract
The global increase in potato production and yield is expected to lead to increased irrigation needs and this has prompted concerns with respect to the sustainability of irrigation water sources, such as groundwater. The magnitude, and inter- and intra-annual variation, of the crop [...] Read more.
The global increase in potato production and yield is expected to lead to increased irrigation needs and this has prompted concerns with respect to the sustainability of irrigation water sources, such as groundwater. The magnitude, and inter- and intra-annual variation, of the crop water requirements and irrigation needs for potato production together with their impact on aquifer storage in a temperate humid region (Prince Edward Island, Canada) were estimated by using long-term (i.e., 2010–2019) daily soil water content (SWC). The amount of supplemental irrigation required for the minimal irrigation scenario (SWC = 70% of field capacity; 0.7 FC) was relatively small (i.e., 17.0 mm); however, this increased significantly, to 85.2 and 189.6 mm, for the moderate (SWC = 0.8 FC) and extensive (SWC = 0.9 FC) irrigation scenarios, respectively. The water supply requirement for the growing season (GS) increased to 154.9 and 344.7 mm for a moderately efficient irrigation system (55% efficiency) for the SWC = 0.8 FC and SWC = 0.9 FC irrigation scenarios, respectively. Depending on the efficiency and the areal extent of the irrigation system, the irrigation water supply requirement can approach or exceed both the GS and annual groundwater recharge. The methodology developed in this research has been translated into a free online tool (SWIB—Soil Water Stress, Irrigation Requirement and Water Balance), which can be applied to other areas or crops where an estimation of soil water deficit and irrigation requirement is sought. Full article
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22 pages, 2591 KiB  
Review
Artificial Intelligence-Based Regional Flood Frequency Analysis Methods: A Scoping Review
by Amir Zalnezhad, Ataur Rahman, Nastaran Nasiri, Khaled Haddad, Muhammad Muhitur Rahman, Mehdi Vafakhah, Bijan Samali and Farhad Ahamed
Water 2022, 14(17), 2677; https://doi.org/10.3390/w14172677 - 29 Aug 2022
Cited by 8 | Viewed by 2495
Abstract
Flood is one of the most destructive natural disasters, causing significant economic damage and loss of lives. Numerous methods have been introduced to estimate design floods, which include linear and non-linear techniques. Since flood generation is a non-linear process, the use of linear [...] Read more.
Flood is one of the most destructive natural disasters, causing significant economic damage and loss of lives. Numerous methods have been introduced to estimate design floods, which include linear and non-linear techniques. Since flood generation is a non-linear process, the use of linear techniques has inherent weaknesses. To overcome these, artificial intelligence (AI)-based non-linear regional flood frequency analysis (RFFA) techniques have been introduced over the last two decades. There are limited articles available in the literature discussing the relative merits/demerits of these AI-based RFFA techniques. To fill this knowledge gap, a scoping review on the AI-based RFFA techniques is presented. Based on the Scopus database, more than 1000 articles were initially selected, which were then screened manually to select the most relevant articles. The accuracy and efficiency of the selected RFFA techniques based on a set of evaluation statistics were compared. Furthermore, the relationships among countries and researchers focusing on AI-based RFFA techniques are illustrated. In terms of performance, artificial neural networks (ANN) are found to be the best performing techniques among all the selected AI-based RFFA techniques. It is also found that Australia, Canada, and Iran have published the highest number of articles in this research field, followed by Turkey, the United Arab Emirates (UAE), India, and China. Future research should be directed towards identification of the impacts of data quantity and quality, model uncertainty and climate change on the AI-based RFFA techniques. Full article
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23 pages, 3734 KiB  
Article
Conceptualising and Implementing an Agent-Based Model of an Irrigation System
by Dengxiao Lang and Maurits Willem Ertsen
Water 2022, 14(16), 2565; https://doi.org/10.3390/w14162565 - 20 Aug 2022
Cited by 7 | Viewed by 2261
Abstract
The literature on irrigated agriculture is primarily concerned with irrigation techniques, irrigation water-use efficiency, and crop yields. How human and non-human agents co-shape(d) irrigation landscapes through their activities and how these actions impact long-term developments are less well studied. In this study, we [...] Read more.
The literature on irrigated agriculture is primarily concerned with irrigation techniques, irrigation water-use efficiency, and crop yields. How human and non-human agents co-shape(d) irrigation landscapes through their activities and how these actions impact long-term developments are less well studied. In this study, we aim to (1) explore interactions between human and non-human agents in an irrigation system; (2) model the realistic operation of an irrigation system in an agent-based model environment, and; (3) study how short-term irrigation management actions create long-term irrigation system patterns. An agent-based model (ABM) was used to build our Irrigation-Related Agent-Based Model (IRABM). We implemented various scenarios, combining different irrigation control methods (time versus water demand), different river discharges, varied gate capacities, and several water allocation strategies. These scenarios result in different yields, which we analyse on the levels of individual farmer, canal, and system. Demand control gives better yields under conditions of sufficient water availability, whereas time control copes better with water deficiency. As expected, barley (Hordeum vulgare, Poaceae) yields generally increase when irrigation time and/or river discharge increase. The effect of gate capacity is visible with yields not changing linearly with changing gate capacities, but showing threshold behaviour. With the findings and analysis, we conclude that IRABM provides a new perspective on modelling the human-water system, as non-human model agents can create the dynamics that realistic irrigation systems show as well. Moreover, this type of modelling approach has a large potential to be theoretically and empirically used to explore the interactions between irrigation-related agents and understand how these interactions create water and yields patterns. Furthermore, the developed user-interface model allows non-technical stakeholders to participate and play a role in modelling work. Full article
(This article belongs to the Special Issue Water and Crops)
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17 pages, 967 KiB  
Article
Impact of log(Kow) Value on the Extraction of Antibiotics from River Sediments with Pressurized Liquid Extraction
by Amélie Chabilan, Nicolette Landwehr, Harald Horn and Ewa Borowska
Water 2022, 14(16), 2534; https://doi.org/10.3390/w14162534 - 18 Aug 2022
Cited by 9 | Viewed by 1808
Abstract
The quantification of antibiotics (ABs) in sediments is an analytical challenge, but at the same time, it is indispensable to understand the fate of ABs in aquatic systems such as rivers. The aim of this study was to develop a comprehensive method to [...] Read more.
The quantification of antibiotics (ABs) in sediments is an analytical challenge, but at the same time, it is indispensable to understand the fate of ABs in aquatic systems such as rivers. The aim of this study was to develop a comprehensive method to determine 19 ABs classified as macrolides, sulfonamides, fluoroquinolones, tetracyclines, clindamycin and trimethoprim in river sediments, using a combination of pressurized liquid extraction and solid phase extraction with the separation and detection with liquid chromatography coupled with mass spectrometry. Our results showed that the physical-chemical properties (e.g., log(Kow) value) of the analytes affected the extraction efficiency. Therefore, we propose to order ABs based on their log(Kow) values instead of traditional classification (macrolides, sulfonamides etc.) to select a suitable extraction solvent. ABs with log(Kow) values below zero (mainly fluoroquinolones and tetracyclines) were difficult to extract with all of the tested protocols compared to ABs with a log(Kow) larger than zero. After comparing different extraction protocols for ABs from solid and sediments, we concluded that recoveries in the range of 0.8 to 64.8% could be achieved for ABs with a log(Kow) value larger than zero using a mixture of acetonitrile and 50 mM phosphoric acid (50/50, v/v) in two extraction cycles at 100 °C. Full article
(This article belongs to the Section Water Quality and Contamination)
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24 pages, 4340 KiB  
Article
Climate Change over the Mediterranean Region: Local Temperature and Precipitation Variations at Five Pilot Sites
by Valeria Todaro, Marco D’Oria, Daniele Secci, Andrea Zanini and Maria Giovanna Tanda
Water 2022, 14(16), 2499; https://doi.org/10.3390/w14162499 - 13 Aug 2022
Cited by 37 | Viewed by 3458
Abstract
The Mediterranean region is one of the most responsive areas to climate change and was identified as a major “hot-spot” based on global climate change analyses. This study provides insight into local climate changes in the Mediterranean region under the scope of the [...] Read more.
The Mediterranean region is one of the most responsive areas to climate change and was identified as a major “hot-spot” based on global climate change analyses. This study provides insight into local climate changes in the Mediterranean region under the scope of the InTheMED project, which is part of the PRIMA programme. Precipitation and temperature were analyzed in an historical period and until the end of this century for five pilot sites, located between the two shores of the Mediterranean region. We used an ensemble of 17 Regional Climate Models, developed in the framework of the EURO-CORDEX initiative, under two Representative Concentration Pathways (RCP4.5 and RCP8.5). Over the historical period, the temperature presents upward trends, which are statistically significant for some sites, while precipitation does not show significant tendencies. These trends will be maintained in the future as predicted by the climate models projections: all models indicate a progressive and robust warming in all study areas and moderate change in total annual precipitation, but some seasonal variations are identified. Future changes in droughts events over the Mediterranean region were studied considering the maximum duration of the heat waves, their peak temperature, and the number of consecutive dry days. All pilot sites are expected to increase the maximum duration of heat waves and their peak temperature. Furthermore, the maximum number of consecutive dry days is expected to increase for most of the study areas. Full article
(This article belongs to the Special Issue Evolution of the Hydrological Regime in Relation to Climate Change)
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21 pages, 1701 KiB  
Review
MinION Nanopore Sequencing Accelerates Progress towards Ubiquitous Genetics in Water Research
by David Werner, Kishor Acharya, Adrian Blackburn, Rixia Zan, Jidapa Plaimart, Ben Allen, Shaaban Mrisho Mgana, Shadrack Mwita Sabai, Franella Francos Halla, Said Maneno Massawa, Alemseged Tamiru Haile, Andualem Mekonnen Hiruy, Jemila Mohammed, Soydoa Vinitnantharat, Thunchanok Thongsamer, Kalyan Pantha, Cesar Rossas Mota Filho and Bruna Coelho Lopes
Water 2022, 14(16), 2491; https://doi.org/10.3390/w14162491 - 12 Aug 2022
Cited by 9 | Viewed by 8339
Abstract
In 2014, Oxford Nanopore Technologies (ONT) introduced an affordable and portable sequencer called MinION. We reviewed emerging applications in water research and assessed progress made with this platform towards ubiquitous genetics. With >99% savings in upfront costs as compared to conventional platforms, the [...] Read more.
In 2014, Oxford Nanopore Technologies (ONT) introduced an affordable and portable sequencer called MinION. We reviewed emerging applications in water research and assessed progress made with this platform towards ubiquitous genetics. With >99% savings in upfront costs as compared to conventional platforms, the MinION put sequencing capacity into the hands of many researchers and enabled novel applications with diverse remits, including in countries without universal access to safe water and sanitation. However, to realize the MinION’s fabled portability, all the auxiliary equipment items for biomass concentration, genetic material extraction, cleanup, quantification, and sequencing library preparation also need to be lightweight and affordable. Only a few studies demonstrated fully portable workflows by using the MinION onboard a diving vessel, an oceanographic research ship, and at sewage treatment works. Lower nanopore sequencing read accuracy as compared to alternative platforms currently hinders MinION applications beyond research, and inclusion of positive and negative controls should become standard practice. ONT’s EPI2ME platform is a major step towards user-friendly bioinformatics. However, no consensus has yet emerged regarding the most appropriate bioinformatic pipeline, which hinders intercomparison of study results. Processing, storing, and interpreting large data sets remains a major challenge for ubiquitous genetics and democratizing sequencing applications. Full article
(This article belongs to the Special Issue Field Methods for Water Quality Surveying)
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19 pages, 10256 KiB  
Article
DRASTIC Index GIS-Based Vulnerability Map for the Entre-os-Rios Thermal Aquifer
by Vanessa Gonçalves, Antonio Albuquerque, Pedro G. Almeida and Victor Cavaleiro
Water 2022, 14(16), 2448; https://doi.org/10.3390/w14162448 - 09 Aug 2022
Cited by 9 | Viewed by 2420
Abstract
The sulphurous mineral waters of ‘Entre-os-Rios’, which is sited in NW Portugal, are famous for their long history as thermal baths dating back at least to the mid-sixteenth century. Because of the singularity of its water composition, especially the highest sulphur content, the [...] Read more.
The sulphurous mineral waters of ‘Entre-os-Rios’, which is sited in NW Portugal, are famous for their long history as thermal baths dating back at least to the mid-sixteenth century. Because of the singularity of its water composition, especially the highest sulphur content, the mineral waters of ‘Entre-os-Rios’ are one of the most important sulphurous waters in Portugal. Despite these mineral waters having a protection perimeter buffer zone to avoid water contamination, there are potentially damaging installations (e.g., fuel station) in the closed protection buffer zone that, according to existing law, are not permitted within the protection perimeters, which defeats the purpose of their delineation. A vulnerability map was created using geographic information system (GIS) tools based on multi-criteria analysis, combining thematic maps and parameters of the DRASTIC index, for evaluating the risk of contamination in the protection area. The results showed that within the perimeter, there was a low risk of pollution. The alluvium-covered terrain was vulnerable to moderate contamination, but it was far from the catchment point. Areas of minimal risk corresponded to locations where the granitic massif had not been significantly weathered. The map enables information collection for a better definition of local resource structures and planning, namely, for restricted areas emplacement where some activities should not be allowed (e.g., agriculture and water prospection), given its influence on the confined granitic aquifer. Full article
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24 pages, 1958 KiB  
Review
Research Progress on Integrated Treatment Technologies of Rural Domestic Sewage: A Review
by Peizhen Chen, Wenjie Zhao, Dongkai Chen, Zhiping Huang, Chunxue Zhang and Xiangqun Zheng
Water 2022, 14(15), 2439; https://doi.org/10.3390/w14152439 - 06 Aug 2022
Cited by 21 | Viewed by 6796
Abstract
The improvement of rural living standards in developing countries and the continuous upgrading of the rural industrial economy have prompted the diversification of rural areas and residential forms. Thus, an integrated rural sewage treatment process has gradually become the mainstream technology for rural [...] Read more.
The improvement of rural living standards in developing countries and the continuous upgrading of the rural industrial economy have prompted the diversification of rural areas and residential forms. Thus, an integrated rural sewage treatment process has gradually become the mainstream technology for rural sewage treatment. Numerous studies have reported the effects of ecological wastewater treatment. Meanwhile, the relevant process technologies, evaluations, and operating models of the integrated rural sewage treatment process have yet to be thoroughly summarized. This review aims to fill these gaps. First, the applicability of artificial wetland, soil infiltration, stabilization pond, and integrated rural sewage treatment process technology in rural sewage treatment are outlined and compared. Second, the process flow, technical characteristics, and economic indicators of typical integrated sewage treatment processes (i.e., Anoxic/Oxic (A/O) process, Membrane Bio-Reactor (MBR) process, biological contact oxidation process, Sequencing Batch Reactor Activated Sludge (SBR) process) are introduced. The engineering application effects of the integrated rural sewage treatment process in different countries are also described. Third, the practical and effective evaluation methods of the integrated rural sewage treatment process are introduced. Bearing in mind the current operation and maintenance management modes of the integrated rural sewage treatment process in developed and developing countries, combined with the national conditions of developing countries, the prospect section provides development proposals for further optimization and improvement of the integrated rural sewage treatment process in developing countries. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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14 pages, 4288 KiB  
Article
Elimination of Microplastics at Different Stages in Wastewater Treatment Plants
by Hyuk Jun Kwon, Haerul Hidayaturrahman, Shaik Gouse Peera and Tae Gwan Lee
Water 2022, 14(15), 2404; https://doi.org/10.3390/w14152404 - 03 Aug 2022
Cited by 23 | Viewed by 6028
Abstract
Microplastic pollution has been widely studied as a global issue due to increased plastic usage and its effect on human and aquatic life. Microplastics originate from domestic and industrial activities. Wastewater treatment plants (WWTPs) play an important role in removing a significant amount [...] Read more.
Microplastic pollution has been widely studied as a global issue due to increased plastic usage and its effect on human and aquatic life. Microplastics originate from domestic and industrial activities. Wastewater treatment plants (WWTPs) play an important role in removing a significant amount of microplastics; otherwise, they end up in bioaccumulation. This study provides knowledge about the characteristics of microplastics, removal efficiency, and the correlation between wastewater quality and microplastic concentrations from three different WWTPs that differ in the type of biological and advanced wastewater treatment techniques that are believed to play an important role in microplastic removal. Microplastics of different types, such as fragments, fibers, and beads, are identified by using an optical microscope before and after the treatment process at each stage to assess the effect of different treatment techniques. In the screening unit and primary clarifier unit, WWTP-B shows the highest removal efficiency with 74.76% due to a distribution flow system installed before the primary clarifier to ensure a constant flow of wastewater. WWTP-B uses a bioreactor consisting of a filter plate coated with activated carbon (BSTS II) that can enhance the adaptability and adhesion of microorganisms and showed that 91.04% of the microplastic was removed. Furthermore, only WWTP-A and WWTP-B were applied coagulation, followed by the disc filter; they showed significant results in microplastic removal, compared to WWTP-C, which only used a disc filter. In conclusion, from all WWTP, WWTP-B shows good treatment series for removing microplastic in wastewater; however, WWTP-B showed a high rate of microplastic removal; unfortunately, large amounts of microplastics are still released into rivers. Full article
(This article belongs to the Special Issue Microplastics Pollution and Solutions)
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12 pages, 2136 KiB  
Article
CME-YOLOv5: An Efficient Object Detection Network for Densely Spaced Fish and Small Targets
by Jianyuan Li, Chunna Liu, Xiaochun Lu and Bilang Wu
Water 2022, 14(15), 2412; https://doi.org/10.3390/w14152412 - 03 Aug 2022
Cited by 24 | Viewed by 4310
Abstract
Fish are indicative species with a relatively balanced ecosystem. Underwater target fish detection is of great significance to fishery resource investigations. Traditional investigation methods cannot meet the increasing requirements of environmental protection and investigation, and the existing target detection technology has few studies [...] Read more.
Fish are indicative species with a relatively balanced ecosystem. Underwater target fish detection is of great significance to fishery resource investigations. Traditional investigation methods cannot meet the increasing requirements of environmental protection and investigation, and the existing target detection technology has few studies on the dynamic identification of underwater fish and small targets. To reduce environmental disturbances and solve the problems of many fish, dense, mutual occlusion and difficult detection of small targets, an improved CME-YOLOv5 network is proposed to detect fish in dense groups and small targets. First, the coordinate attention (CA) mechanism and cross-stage partial networks with 3 convolutions (C3) structure are fused into the C3CA module to replace the C3 module of the backbone in you only look once (YOLOv5) to improve the extraction of target feature information and detection accuracy. Second, the three detection layers are expanded to four, which enhances the model’s ability to capture information in different dimensions and improves detection performance. Finally, the efficient intersection over union (EIOU) loss function is used instead of the generalized intersection over union (GIOU) loss function to optimize the convergence rate and location accuracy. Based on the actual image data and a small number of datasets obtained online, the experimental results showed that the mean average precision (mAP@0.50) of the proposed algorithm reached 94.9%, which is 4.4 percentage points higher than that of the YOLOv5 algorithm, and the number of fish and small target detection performances was 24.6% higher. The results show that our proposed algorithm exhibits good detection performance when applied to densely spaced fish and small targets and can be used as an alternative or supplemental method for fishery resource investigation. Full article
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15 pages, 855 KiB  
Review
Resource Utilization of Acid Mine Drainage (AMD): A Review
by Jiaqiao Yuan, Zhan Ding, Yunxiao Bi, Jie Li, Shuming Wen and Shaojun Bai
Water 2022, 14(15), 2385; https://doi.org/10.3390/w14152385 - 01 Aug 2022
Cited by 20 | Viewed by 7237
Abstract
Acid mine drainage (AMD) is a typical type of pollution originating from complex oxidation interactions that occur under ambient conditions in abandoned and active mines. AMD has high acidity and contains a high concentration of heavy metals and metalloids, posing a serious threat [...] Read more.
Acid mine drainage (AMD) is a typical type of pollution originating from complex oxidation interactions that occur under ambient conditions in abandoned and active mines. AMD has high acidity and contains a high concentration of heavy metals and metalloids, posing a serious threat to ecological systems and human health. Over the years, great progress has been made in the prevention and treatment of AMD. Remediation approaches like chemical neutralization precipitation, ion exchange, membrane separation processes, and bioremediation have been extensively reported. Nevertheless, some limitations, such as low efficacy, excessive consumption of chemical reagents, and secondary contamination restrict the application of these technologies. The aim of this review was to provide updated information on the sustainable treatments that have been engaged in the published literature on the resource utilization of AMD. The recovery and reuse of valuable resources (e.g., clean water, sulfuric acid, and metal ions) from AMD can offset the cost of AMD remediation. Iron oxide particles recovered from AMD can be applied as adsorbents for the removal of pollutants from wastewater and for the fabrication of effective catalysts for heterogeneous Fenton reactions. The application of AMD in beneficiation fields, such as activating pyrite and chalcopyrite flotation, regulating pulp pH, and leaching copper-bearing waste rock, provides easy access to the innovative utilization of AMD. A review such as this will help researchers understand the progress in research, and identify the strengths and weaknesses of each treatment technology, which can help shape the direction of future research in this area. Full article
(This article belongs to the Special Issue Mining Wastewater Treatment and Reuse)
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21 pages, 2877 KiB  
Article
Data-Driven Community Flood Resilience Prediction
by Moustafa Naiem Abdel-Mooty, Wael El-Dakhakhni and Paulin Coulibaly
Water 2022, 14(13), 2120; https://doi.org/10.3390/w14132120 - 02 Jul 2022
Cited by 5 | Viewed by 3502
Abstract
Climate change and the development of urban centers within flood-prone areas have significantly increased flood-related disasters worldwide. However, most flood risk categorization and prediction efforts have been focused on the hydrologic features of flood hazards, often not considering subsequent long-term losses and recovery [...] Read more.
Climate change and the development of urban centers within flood-prone areas have significantly increased flood-related disasters worldwide. However, most flood risk categorization and prediction efforts have been focused on the hydrologic features of flood hazards, often not considering subsequent long-term losses and recovery trajectories (i.e., community’s flood resilience). In this study, a two-stage Machine Learning (ML)-based framework is developed to accurately categorize and predict communities’ flood resilience and their response to future flood hazards. This framework is a step towards developing comprehensive, proactive flood disaster management planning to further ensure functioning urban centers and mitigate the risk of future catastrophic flood events. In this framework, resilience indices are synthesized considering resilience goals (i.e., robustness and rapidity) using unsupervised ML, coupled with climate information, to develop a supervised ML prediction algorithm. To showcase the utility of the framework, it was applied on historical flood disaster records collected by the US National Weather Services. These disaster records were subsequently used to develop the resilience indices, which were then coupled with the associated historical climate data, resulting in high-accuracy predictions and, thus, utility in flood resilience management studies. To further demonstrate the utilization of the framework, a spatial analysis was developed to quantify communities’ flood resilience and vulnerability across the selected spatial domain. The framework presented in this study is employable in climate studies and patio-temporal vulnerability identification. Such a framework can also empower decision makers to develop effective data-driven climate resilience strategies. Full article
(This article belongs to the Topic Natural Hazards and Disaster Risks Reduction)
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