This study evaluates the physical, chemical, and biological properties of wastewater—comprising domestic sewage and agricultural drainage water—both before and after treatment to assess the efficiency of the applied processes. The physical properties, including total suspended solids (TSS) and color, demonstrated significant [...] Read more.

This study evaluates the physical, chemical, and biological properties of wastewater—comprising domestic sewage and agricultural drainage water—both before and after treatment to assess the efficiency of the applied processes. The physical properties, including total suspended solids (TSS) and color, demonstrated significant improvements post-treatment, withTSS reduction reaching 91.4% and color removal at 99.5%, indicating the effectiveness of ultrafiltration and coagulation techniques. Chemically, the total dissolved solids (TDS) concentration decreased from 838.2 to 375.5 mg·L⁻¹, aligning with environmental standards and ensuring suitability for irrigation. Additional reductions were observed in biochemical oxygen demand (BOD) and chemical oxygen demand (COD), with removal efficiencies of 86.5% and 83.7%, respectively, highlighting the system’s capability in reducing organic pollutants. Biologically, the treatment process achieved 99.9% removal efficiencies for bothTotal Coliform andE. coli, meeting world health organization (WHO) guidelines for microbial safety. The water quality index (WQI) analysis classified the treated water in the “Excellent” category, demonstrating an overall enhancement in water quality. Beyond these performance evaluations, this study introduces a novel approach by employing conventional treatment techniques on a blended wastewater—comprising domestic sewage and agricultural drainage water—operated under real operational conditions to achieve safe and sustainable irrigation reuse. This study hypothesizes that the synergistic integration of ultrafiltration with sodium hypochlorite disinfection—without relying on biological treatment—can significantly enhance water quality for sustainable irrigation.Full article

Supplementary material:
Supplementary File 1 (ZIP, 220 KiB)

Agricultural water trading is typically considered an effective water management mechanism, and decisions made by agricultural agents highly influence its effectiveness. Agent-based modelling (ABM) simulating agricultural agents in the water trading context has drawn attention due to its distinguishable features driven by interactions, [...] Read more.

Agricultural water trading is typically considered an effective water management mechanism, and decisions made by agricultural agents highly influence its effectiveness. Agent-based modelling (ABM) simulating agricultural agents in the water trading context has drawn attention due to its distinguishable features driven by interactions, heterogeneity, independence, and the evolving characteristics of the decisions of agents. Given its strengths and potential to simulate a complex water trading system, the objectives of this study are to (a) provide a comprehensive review of the status of ABM applications in agricultural water trading through a systematic review and (b) identify the primary trends of the empirical nature of ABM studies, approaches to modelling agricultural agent decisions, uncertainty assessments, and validation approaches in ABM studies. The results show that there is a relationship between the empirical nature of the ABM studies, selected decision models to describe agricultural agents, analysed uncertainties, and the validation approaches employed in ABM studies. This study also provides a future research agenda, including exploring attributes with a direct influence on agent trading decisions and integrating the effects of uncertain trading decisions, long-term water availability changes, and water quality into ABM outcomes.Full article

Supplementary material:
Supplementary File 1 (ZIP, 117 KiB)

Microplastics (MPs) resulting from plastic fragmentation with a size less than 5 mm have become one of the main pollutants endangering the water environment. Therefore, it is necessary to know about the abundance and size distribution of MPs in sewage waters and their [...] Read more.

Microplastics (MPs) resulting from plastic fragmentation with a size less than 5 mm have become one of the main pollutants endangering the water environment. Therefore, it is necessary to know about the abundance and size distribution of MPs in sewage waters and their relationship with water quality. In this study, water samples are collected from 20 sewage outlets in Guilin, China to analyze the abundance and morphology of the MPs and their hydrochemical characteristics. Multivariate statistical analyses are conducted to identify the major factors related to the MP distribution in sewage water samples. Results showed that MPs in sewage water samples are mainly composed of fiber and film, and about 67.8% are sized <0.3 mm. The abundance is in the range of 6 (±1)–47 (±3) items/L. The correlation analysis presents that the abundance of MPs is weakly correlated with hydrochemical parameters and metal ions due to the complexity of the abundance data. The redundancy analysis indicates that the MP morphology distribution is significantly affected by NO₃–N, Zn, Ca, and Cu contents, and the MP size distribution is mainly related to Zn, Ca, and Cu contents. Adsorption kinetics are analyzed using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models, revealing that the adsorption process is predominantly governed by chemisorption for smaller MPs (0.3–0.5 mm), while larger MPs (1.0–5.0 mm) are constrained by internal diffusion. Isothermal adsorption experiments are fitted using Langmuir and Freundlich models, indicating that the adsorption of nutrients (NH₃–N, TN, TP) and metal ions (Ca, Mg, Cu, Pb, Zn) on MPs follows a monolayer adsorption mechanism, with smaller MPs showing higher adsorption capacities due to their larger specific surface areas. This study highlights the occurrence characteristics and environmental influencing factors of MPs in sewage water, which may be significant for future studies on the pollution control of MPs.Full article

Supplementary material:
Supplementary File 1 (ZIP, 538 KiB)

The occurrence and dissemination of resistomes within environmental compartments are worrisome, considering the huge public health challenge they may pose. Treated wastewater from wastewater treatment plants (WWTPs) has been shown to contain enormous and diversified bacterial communities with antibiotic resistance gene (ARG) profiles, [...] Read more.

The occurrence and dissemination of resistomes within environmental compartments are worrisome, considering the huge public health challenge they may pose. Treated wastewater from wastewater treatment plants (WWTPs) has been shown to contain enormous and diversified bacterial communities with antibiotic resistance gene (ARG) profiles, and it provides tolerable environments for their prefoliation and dissemination. This study considered the ARG profiles of a municipal WWTP that also collects wastewater from diverse production factories with the aim to determine the efficacy of the wastewater treatment plant and the prevalence of ARGs in the various compartments. The WWTP employs the conventional activated sludge system in its treatment. Our study employed metagenomic screening of ARGs and mobile genetic elements (MGEs), using different PCR assays of untreated wastewater (UTW) and treated wastewater (TWW) from the WWTP. Downstream- (RWD) and upstream- (RWU) receiving river water was also screened. Twenty-nine ARGs and two mobile genetic elements (MGEs) were screened for. Antibiotic resistance genes to all the classes of antibiotics studied were detected in all the samples. Of the twenty-nine ARGs screened for, twenty-four (82.8%) were detected, and one MGE was detected from the two screened for in the samples with the highest ARG prevalence detected in the UTW. This study shows that ARGs proliferate in every compartment of the WWTP, even in the treated water and the receiving rivers, portraying that the WWTP system was not efficient in getting rid of the resistomes, creating an important channel for human acquisition of resistant determinants to antibiotics.Full article

Water scarcity presents one of the greatest challenges of our time. Especially in naturally water-scarce regions, the need for additional water resources is rising, requiring innovative and site-adapted technologies. The decision for a specific technology is mostly associated with high investment costs and [...] Read more.

Water scarcity presents one of the greatest challenges of our time. Especially in naturally water-scarce regions, the need for additional water resources is rising, requiring innovative and site-adapted technologies. The decision for a specific technology is mostly associated with high investment costs and a long life cycle time, which requires a conscientious and transparent decision-making process. In this review, such a framework is developed for selected non-conventional water technologies and strategically evaluated with the goal to support a sustainable technology application based on specific boundary conditions. This is achieved by a matrix-based assessment and the development of key indicators respecting the availability, applicability, environmental impact, scalability, and economic viability of the selected technologies. Based on a wide literature review, the developed methodology involves a systematic comparison of technologies for desalination, water reuse, groundwater utilization, agricultural reuse, and unconventional approaches like cloud seeding, dew water, and fog water harvesting. The developed indicators cover most parameters of the respective categories based on the individual designs. Subsequently, the different technologies are analyzed by a matrix-based evaluation, highlighting various strengths and weaknesses and providing insights into technology application based on regional conditions. The discussion interprets the findings, deriving implications for dry environments, acknowledging limitations, and suggesting pathways for future research. The matrix-based evaluation is illustrated by an example from the Jordan Valley for a brackish water desalination plant. Through this analytical framework, this study contributes to the discourse on sustainable water solutions and a transparent decision-making process, as well as offers valuable insights for policymakers, researchers, and industries during a decision-making progress.Full article

The Haihe River system, located in the East Asian monsoon climate zone, experiences uneven precipitation and significant variability, leading to frequent droughts and floods that disrupted economic and social development. While many studies have assessed the risks of droughts and floods in the [...] Read more.

The Haihe River system, located in the East Asian monsoon climate zone, experiences uneven precipitation and significant variability, leading to frequent droughts and floods that disrupted economic and social development. While many studies have assessed the risks of droughts and floods in the Haihe River Basin, most focus on the basin as a whole, leaving a notable gap in research on the dynamics of the northern region. This study analyzed historical drought and flood data, incorporating instrument precipitation records from 1960 to 2009 to reconstruct conditions in the northern Haihe River Basin from 1470 to 2009. Using methods like the Mann–Kendall test, sliding averages, continuous wavelet technology, and spatial analysis, this study examined the trends, change points, periodicity, and spatial patterns of drought and flood variability. The findings showed that from 1470 to 2009, drought and flood variabilities occurred 73.15% of the time in the northern Haihe system, with peak disaster periods in the 17th, 19th, and 20th centuries. The region has alternated between wet and dry cycles, with a notable dry trend emerging in the 21st century. A prominent 35~50-year cycle in drought and flood occurrences was identified, along with high-frequency oscillations. Flood periods were most frequent in the eastern plains, while drought periods were more prevalent in the western areas, gradually shifting eastward since 1950. The research also revealed correlations between drought and flood variability and solar activity, with peak years coinciding with higher frequencies of these events. El Niño events were associated with drought periods, while La Niña events tended to cause flood periods. Factors such as solar activity, El Niño–Southern Oscillation, monsoon climate patterns, topography, and human influences shaped the dynamics of drought and flood variability in the northern Haihe River Basin. A comparison with other regions showed consistent wet and dry cycles over the past 500 years, particularly between the northern and southern parts of the basin. However, since the 21st century, the southern region has remained humid, while the northern region has become increasingly drier. Despite similar temperature trends, humidity changes have diverged in the modern warming period. Although the underlying factors driving drought and flood variability were not fully understood and required a further exploration of the global climate system’s interactions, these findings emphasized the need for targeted strategies to address the ongoing challenges of drought and flood management in the northern Haihe River Basin.Full article

The accurate knowledge of groundwater availability and its variations is crucial for sustainable groundwater management; in this framework, the water balance is a useful tool to assess the availability of water resources. Currently, the management authority needs a more precise evaluation of groundwater [...] Read more.

The accurate knowledge of groundwater availability and its variations is crucial for sustainable groundwater management; in this framework, the water balance is a useful tool to assess the availability of water resources. Currently, the management authority needs a more precise evaluation of groundwater availability to face the rising freshwater demand. In this work, water balance has been determined for the main aquifers in the central Apennines (Italy)—over 2000 km² wide—and the calculated outflow was compared with springs’ discharge from the data. Inflow data were collected over a 6-year period, from 2018 to 2023, considering both rainfall and snow; the contribution of the snow melting has often been omitted or rarely considered as immediate liquid contribution in the previous works, where usually only liquid inflows from rain have been considered. The snow contribution has been properly evaluated from a recent network of snow gauges and included in the total precipitation for more accurate results. Indeed, for each aquifer, monthly inflow datasets from rain gauges have been interpolated inside the structure using the equations obtained from regression lines and then used for a water balance assessment. An initial comparison of water balances, estimated with and without snow data, demonstrates that neglecting the snow contribution can lead to an underestimation of infiltration values. A comparison between calculated outflows including the snow melt and the measured springs’ discharge has shown a good correspondence for each investigated aquifer.Full article

The moving particle semi-implicit method (MPS) has been employed to numerically simulate fluid flows. Further, some studies have used the MPS method to solve the Darcy–Brinkman equation, which also expresses fluid flow in porous media. However, these studies simulated flows only in porous [...] Read more.

The moving particle semi-implicit method (MPS) has been employed to numerically simulate fluid flows. Further, some studies have used the MPS method to solve the Darcy–Brinkman equation, which also expresses fluid flow in porous media. However, these studies simulated flows only in porous media with high permeability, not in relatively low permeability. Thus, this study developed a numerical simulation method that employs Navier–Stokes equations to describe flow in surface water and the Richards equations, derived from the Darcy law and the law of conservation of mass, to describe water flow in porous media, and it uses the MPS method to discretize those equations. This numerical simulation method was then evaluated by comparing the numerical simulation results with previously obtained experimental results for fluid draining from the bottom of a column, which was first packed with silica sand saturated with water and then filled with water to 25 cm above the top surface of the sand, which had an intrinsic permeability of 1.737 × 10^–11 m², a porosity of 0.402, van Genuchten parameters of 0.231 kPa^–1 and 9.154, a residual gas saturation of 0.0, and a residual water saturation of 0.178. The numerical simulation was able to simulate the decrease in the level of the surface water above the silica sand in the column, similar to the column experimental results. However, the decrease in the saturated water in the silica sand obtained by the numerical simulation was almost consistent with the experimental results.Full article

Groundwater is a vital resource for ecosystems, with its recharge process influenced by climate change and urbanization. The transformation of natural and urban landscapes and the over-extraction of groundwater contribute to its depletion and degradation. Groundwater recharge and management are intricately linked to [...] Read more.

Groundwater is a vital resource for ecosystems, with its recharge process influenced by climate change and urbanization. The transformation of natural and urban landscapes and the over-extraction of groundwater contribute to its depletion and degradation. Groundwater recharge and management are intricately linked to land use and the landscape. Despite this close connection, spatially integrating groundwater recharge strategies in the landscape context remains underexplored. This systematic review synthesizes state-of-the-art research at the intersection of spatial planning, landscapes, and groundwater recharge. We employed a combination of bibliometric visualization and thematic analysis and reviewed 126 studies published between 1990 and April 2024 from the Scopus and Web of Science databases. Based on their objectives and outcomes, we found four prominent themes in these clusters: groundwater recharge potential studies, groundwater vulnerability studies, design-based studies, and participatory studies. When organized iteratively, these clusters can become potential building blocks of a framework for a landscape-based groundwater recharge approach. With interdisciplinary collaboration, spatial visualization and mapping, a co-creative design, and a feedback mechanism at its core, this approach can enhance stakeholder communication and translate highly specialized technical knowledge into adaptive, actionable insights. This study also highlights that including spatial design can help develop landscape-based groundwater recharge for long-term sustainable regional development.Full article

Accurate characterization of aquifer hydrogeological parameters is critical for sustainable groundwater resource management. Traditional methods such as pumping tests often assume aquifer homogeneity and require substantial resources, limiting their applicability for large-scale heterogeneous systems. This study proposes a novel approach to estimate the [...] Read more.

Accurate characterization of aquifer hydrogeological parameters is critical for sustainable groundwater resource management. Traditional methods such as pumping tests often assume aquifer homogeneity and require substantial resources, limiting their applicability for large-scale heterogeneous systems. This study proposes a novel approach to estimate the spatial distribution of hydraulic conductivity (T) and specific storage (Ss) in the Qingtongxia Irrigation Area, utilizing canal stage fluctuations as natural stimuli. By analyzing high-frequency groundwater level responses from monitoring wells during irrigation channel operations, we employed a Sequential Linear Estimator (SLE) method combined with canal stage tomography to invert aquifer parameters. The results demonstrate that the inverted hydraulic conductivity distribution aligns well with lithological variations and historical data, showing higher values in the southern alluvial fan and lower values in the northern plains. The SLE method effectively captured aquifer heterogeneity, with RMSE and correlation coefficients between pumping test and inversion results improving to 1.81 and 0.76 after excluding outliers. This work highlights the potential of natural stimuli (e.g., irrigation-induced canal fluctuations) for basin-scale hydrogeological parameter estimation, offering a cost-effective alternative to traditional methods. The findings provide valuable insights for groundwater modeling and resource management in arid regions with intensive irrigation systems.Full article

Floods pose significant risks worldwide, impacting lives, infrastructure, and economies. The Susurluk basin, covering 24,319 km² in Türkiye, is highly vulnerable to flooding. This study updates the flood management plan for the basin, integrating hydrological modeling, GIS-based flood mapping, and early warning [...] Read more.

Floods pose significant risks worldwide, impacting lives, infrastructure, and economies. The Susurluk basin, covering 24,319 km² in Türkiye, is highly vulnerable to flooding. This study updates the flood management plan for the basin, integrating hydrological modeling, GIS-based flood mapping, and early warning system evaluations in alignment with the EU Flood Directive. A total of 503 hydrodynamic models (226 one-dimensional and 277 two-dimensional) were developed, analyzing 2116 km of stream length. As a result of the evaluation, the capacities of only 33 streams were found to be sufficient. Flood hazard and risk maps for the Q₅₀, Q₁₀₀, Q₅₀₀, and Q₁₀₀₀ return periods identified the remaining 470 high-risk locations as requiring urgent intervention. Economic risk assessments revealed significant exposure of critical infrastructure, especially in urban areas with populations over 100,000. Furthermore, the study introduces a prioritization framework for intervention that balances socioeconomic costs and environmental impacts. Economic damage assessments estimate potential losses in critical infrastructure, including residential areas, industrial zones, and transportation networks. The findings highlight the importance of proactive flood risk mitigation strategies, particularly in high-risk urban centers. Overall, this study provides a data-driven, replicable model for flood risk management, emphasizing early warning systems, spatial analysis, and structural/non-structural mitigation measures. The insights gained from this research can guide policymakers and urban planners in developing adaptive, long-term flood management strategies for flood-prone regions.Full article

Involving wetland protection policies in the simulation of the wetland biodiversity pattern has the potential to improve the accuracy of policy-making. In this research, by combining the Cellular Automata Markov Model (CA-Markov) for land use change simulation and a wetland Biodiversity Estimation Model [...] Read more.

Involving wetland protection policies in the simulation of the wetland biodiversity pattern has the potential to improve the accuracy of policy-making. In this research, by combining the Cellular Automata Markov Model (CA-Markov) for land use change simulation and a wetland Biodiversity Estimation Model Based on Hydrological Pattern and Connectivity (BEHPC), we put forward a comprehensive framework that integrates policy stage division, the identification of stage characteristics, and biodiversity prediction. This framework divided the wetland conservation policies implemented in the study area into three stages: promoting (1995−2005), strengthening (2005–2010), and stabilizing (2010–2020). CA-Markov verification confirmed the stages’ consistency with actual policy implementation, indicating its usability. Using the land use data of different policy stages as input for the CA-Markov model, we then predicted the wetland biodiversity pattern in 2030 under different scenarios. The results showed that the land use and wetland protection policies implemented during 2010–2020 were most beneficial for enhancing wetland biodiversity in the study area, with an expected increase of about 8% if continued. This study offers technical and scheme references for the future evaluation of wetland-related policies at the regional scale. It also provides guidance for optimizing the spatial structure and providing numerical goals for land use and wetland protection.Full article

In Thailand, droughts severely impact agriculture, particularly in non-irrigated areas, which comprise 76.4% of the country’s farmland. This highlights the need for sustainable energy solutions to mitigate environmental impacts. Despite government efforts, including over 900 Solar Water Pumping (SWP) demonstration units, many farmers [...] Read more.

In Thailand, droughts severely impact agriculture, particularly in non-irrigated areas, which comprise 76.4% of the country’s farmland. This highlights the need for sustainable energy solutions to mitigate environmental impacts. Despite government efforts, including over 900 Solar Water Pumping (SWP) demonstration units, many farmers remain hesitant to adopt this technology. This study examines the factors influencing farmers’ willingness to invest in SWP in Thailand’s drought-prone north and northeast regions, the most affected areas. Data were collected from 210 families—127 in the north (NC) and 83 in the northeast (NEC)—through surveys, interviews, and observations. Results show that 75.6% of NC and 77.1% of NEC farmers are willing to invest. However, barriers include financial constraints, reliance on government aid, uncertainty about returns, and lack of information. The estimated willingness-to-pay per household is USD 1438 in NC and USD 1518 in NEC, both exceeding the cost of a basic SWP system. Education, land ownership, and debt influence investment decisions, while the cultivation area impacts the amount invested. To increase adoption and combat climate change, tailored financial support, such as loan programs and leasing options, are needed for farmers in non-irrigated regions.Full article

In order to ensure the smooth progress of foundation pit engineering, it is necessary to identify and control the seepage risk. At present, there are few research studies and applications on the seepage risk assessment of foundation pits, and the optimization of curtain [...] Read more.

In order to ensure the smooth progress of foundation pit engineering, it is necessary to identify and control the seepage risk. At present, there are few research studies and applications on the seepage risk assessment of foundation pits, and the optimization of curtain depth and the interrelation and optimal combination of design variables are rarely considered in the optimization design of foundation pit dewatering scheme based on the objective function method. According to the geological and hydrogeological conditions of the research area, a mathematical model for optimizing foundation pit dewatering was established. The model takes the minimum total dewatering cost as the objective function and comprehensively considers decision-making variables. Additionally, it also takes into account constraints such as the drawdown depth of the water level in a single well and the pumping flow rate of a single well. The calculation results indicate that the errors between the measured water levels and the simulated water levels are within ±3.5%, suggesting that the parameter inversion results are effective. The horizontal and vertical permeability coefficients of the phreatic aquifer are 3.0 m/d and 0.45 m/d, respectively, and the horizontal and vertical permeability coefficients of confined aquifer are 10.28 m/d and 1.25 m/d, respectively. The horizontal and vertical permeability coefficients of the confined aquifer are 10.28 m/d and 1.25 m/d, respectively. Nine different excavation dewatering schemes that curtain depths of 66 m, 61 m, and 56 m were designed, and the optimal excavation dewatering scheme was determined by comparing the total dewatering cost. This scheme has the advantages of shortening the dewatering time, reducing the impact of foundation pit dewatering on the surrounding environment, and saving the total cost of dewatering. The research results provide a relevant decision-making basis for managers.Full article

Supplementary material:
Supplementary File 1 (ZIP, 479 KiB)

In this study, we studied the process of recovering copper from mine-leached water at an altitude of 4500 m. The process was ion exchange–esolution–nanofiltration–separation–cyclone electrodeposition. As a result, high-purity copper cathodes were produced. The study demonstrated that the maximum adsorption capacity of ion [...] Read more.

In this study, we studied the process of recovering copper from mine-leached water at an altitude of 4500 m. The process was ion exchange–esolution–nanofiltration–separation–cyclone electrodeposition. As a result, high-purity copper cathodes were produced. The study demonstrated that the maximum adsorption capacity of ion exchange resin D402 for Cu²⁺ reached 174.6 g/L and the efficiency of Cu²⁺ adsorption and eluent was found to be 97.2% and 94.2%, respectively. The results of Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the resin contains -OH and -NH₂. The lone pair electrons on O and N atoms can form coordination bonds with copper ions to form stable complexes. The results of X-ray photoelectron spectroscopy (XPS) analysis indicated that copper ions were absorbed into the resin. The recovery efficiency of Cu²⁺ throughout the entire process reaches 95.1%, and the purity of the resulting copper cathode reaches 99.997%. This method is distinguished by a straightforward process, minimal environmental impact, optimal operating conditions, high copper recovery efficiency, and a high copper grade.Full article

Taihu Lake is a large lake with high levels of eutrophication. Cyanobacterial outbreaks significantly affect the ecological environment and socioeconomic development. The chlorophyll-a (Chl-a) concentration, which is crucial for monitoring eutrophication, can be obtained through remote sensing inversion, and the random, sudden, and [...] Read more.

Taihu Lake is a large lake with high levels of eutrophication. Cyanobacterial outbreaks significantly affect the ecological environment and socioeconomic development. The chlorophyll-a (Chl-a) concentration, which is crucial for monitoring eutrophication, can be obtained through remote sensing inversion, and the random, sudden, and complex changes impose stringent requirements on the monitoring scale. However, single remote sensing images often fail to meet both the high temporal and spatial resolution requirements for Chl-a monitoring. This study took Taihu Lake as the research object, combined COMS-1 GOCI (1 h/500 m resolution) and Sentinel-2 MSI (5 d/10 m resolution) inverted Chl-a data, and developed a precorrection-based spatiotemporal downscaling method (PC-STDM). After eliminating systematic bias, the model used temporal weighting downscaling (TWD) and regression trend assessment downscaling (TRAD) methods to downscale the inverted Chl-a data, improving the temporal resolution of the Sentinel-2 MSI Chl-a inversion data from 5 d to 1 h. The verification resulted in an average R² of 0.87 between the COMS-1 GOCI and Sentinel-2 MSI Chl-a data after adaptive correction. A comparison with the measured Chl-a data yielded a maximum fitting coefficient of 0.98, verifying the credibility of the model. The downscaled Chl-a concentration data detailed hourly changes and development trends, providing support for water quality monitoring in the Taihu Lake area.Full article

Water quality is a fundamental parameter for assessing the suitability of surface waters. Likewise, the hydrochemical behavior is critically important to understand for rivers used in irrigation. This study aims to evaluate and characterize the surface water quality of the Voghji River catchment [...] Read more.

Water quality is a fundamental parameter for assessing the suitability of surface waters. Likewise, the hydrochemical behavior is critically important to understand for rivers used in irrigation. This study aims to evaluate and characterize the surface water quality of the Voghji River catchment basin for irrigation, as it reveals the hydrochemical origins in the catchment basin. Nine key parameters, including EC, Cl⁻, SO₄²⁻, Ca²⁺, Mg²⁺, Na⁺, K⁺, CO₃²⁻, and HCO₃⁻, were measured at seven sampling points in July and September 2017. The ion concentration patterns in July followed the sequence: Ca²⁺ > Na⁺ > K⁺ > Mg²⁺ and HCO₃⁻ > SO₄²⁻ > Cl⁻ > CO₃²⁻, while in September, they were Ca²⁺ > Na⁺ > Mg²⁺ > K⁺ and HCO₃⁻ > SO₄²⁻ > Cl⁻ > CO₃²⁻. The sequences were almost similar between the two months, with minor differences in cation distribution, particularly between Mg²⁺ and K⁺. Overall, Ca²⁺ and HCO₃⁻ were the dominant ions in the studied surface water samples. The concentrations of K⁺, Na⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄²⁻, and HCO₃⁻ were found to be well below the FAO irrigation water standards, indicating that the waters of the Voghji River and its tributaries (Achanan, Vachagan, and Geghi) were generally safe for irrigation. However, the FAO threshold value was exceeded only for CO₃²⁻ in the Vachagan River in Kapan Town. The chemical analysis of surface waters in the Voghji River catchment basin revealed dominant Ca²⁺-HCO₃⁻ and mixed Ca²⁺-K⁺-SO₄²⁻-Cl⁻ facies, with key geochemical processes including carbonate and gypsum dissolution, silicate weathering, and cation exchange. Ionic correlations indicated that Na⁺ and Cl⁻ sources were influenced by both natural (e.g., halite dissolution, weathering) and anthropogenic inputs, while Ca²⁺ and Mg²⁺ primarily originated from carbonate dissolution. The Gibbs diagram suggested that rock–water interactions were the primary natural mechanism controlling the water chemistry, with evaporation also playing a significant role. Various indices, including the Kelly index, magnesium adsorption ratio, sodium percentage, sodium adsorption ratio, permeability index, potential salinity, residual sodium carbonate, soluble sodium percentage, and irrigation water quality index, were applied, along with US Salinity Laboratory diagram and Wilcox diagram, to further assess the irrigation suitability. Most indices confirmed the suitability of the waters for irrigation; however, the Achanan River near the mouth and the Voghji River downstream of Kapan Town exhibited moderate salinity levels, underscoring the need for water management to prevent potential soil degradation.Full article

Water scarcity poses rigorous challenges to socio-economic development, necessitating more efficient options for water and resource management [...]Full article

This study investigates the impact of port construction on suspended solid concentrations and key water quality parameters in Jinhae Bay, using seventeen years of water quality data up to 2020. The study highlights the significant impact of suspended solids on marine water quality, [...] Read more.

This study investigates the impact of port construction on suspended solid concentrations and key water quality parameters in Jinhae Bay, using seventeen years of water quality data up to 2020. The study highlights the significant impact of suspended solids on marine water quality, particularly in areas affected by dredging operations at Busan New Port. Suspended solids concentrations peaked at 92 mg/L, exceeding 10 mg/L in both surface and bottom waters, with the highest levels near the port. These solids were identified as key predictors of coastal eutrophication in locations such as Jinhae Bay 01, 17, 19, where positive correlations with Chl-a suggest their role in promoting eutrophication. The highest average Chl-a levels were recorded at Jinhae Bay 01 (9.82 µg/L), while the lowest were at Jinhae Bay 14 (3.2 µg/L). The WQI, ranged from 1 to 3, with Jinhae Bay 19 showing the highest value and Jinhae Bay 14 the lowest due to low dissolved oxygen levels. Using ARIMA modeling, the study effectively analyzed the time-series dynamics of suspended solids, demonstrating their relationships with Chl-a and WQI components. These findings underscore the importance of monitoring and managing suspended solids to mitigate the risk of eutrophication and protect marine ecosystems in the context of port development.Full article