This study was performed to investigate the effects of climate change on a semi-arid catchment. The Soil & Water Assessment Tool (SWAT) was used for hydrological modeling. Two Representative Concentration Pathway scenarios (RCP4.5 and RCP8.5) were utilized for assessment in the periods 2050-2069 and 2080-2099. Calibration and validation were performed using the SWAT Calibration and Uncertainty Program (SWAT-CUP). Future climate data were prepared using the Model for Interdisciplinary Research on Climate (MIROC5) from Coupled Model Intercomparison Project Phase 5 (CMIP5). Under the impacts of the RCP4.5 scenario, the temperature in the Shakardara district indicated a +3.4°C and +3.8°C rise during 2050-2069 and 2080-2099, respectively. However, considering RCP8.5, it will continue to rise by +4.4°C and +6.54°C in the same periods. Runoff will decrease by 71.47% and 67.88% considering the RCP4.5 scenario. It is going to change to 63.03% and 65.2% under the RCP8.5 scenario. The Shah wa Arus dam in the catchment will fail due to severe drought. Therefore, we argue that climate change will exacerbate water problems and cause drought in the Shakardara district and inhabitants in this district will be forced to migrate because the main source of income for people in the Shakardara is agriculture and the water shortage will cause economic problems. It is therefore recommended to take action about future climate-related migration by developing a viable plan for water management considering climate change in the Shakardara district.

This research pioneers the innovative use of glass as a standalone adsorbent for the extraction of crystal violet (CV) dye from aqueous solutions, which is a novel method that has not been previously explored. A unique phosphate-based glass was synthesized using the conventional melt quenching process. The resulting glass was comprehensively characterized using a wide array of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, Raman spectroscopy, thermal gravimetric analysis (TGA), and X-ray diffraction (XRD). This study marks the first successful application of phosphate-based glass as an adsorbent for CV dye removal, revealing a significant adsorption capacity. The adsorption process was influenced by various physicochemical parameters, which were systematically investigated. Both the Freundlich isotherm and pseudo-second-order models provided excellent fits to the isothermal and kinetic adsorption data, respectively. Detailed kinetic studies showed that the adsorption process followed pseudo-second-order kinetics and conformed to the Freundlich isotherm model. The maximum adsorption capacity observed was 266.745 mg/g. Thermodynamic assessments indicated that the CV dye adsorption process was both spontaneous and exothermic. These findings highlight the exceptional potential of the synthesized phosphate-based glass for effective wastewater treatment applications involving CV dye. This novel approach opens up new avenues for the use of glass materials in environmental remediation and could significantly impact future wastewater treatment technologies.

Over the last two decades, Artificial Neural Networks (ANNs) have been increasingly used to predict watershed responses due to their effectiveness in modeling complex precipitation-runoff phenomena. In this research, a multi-layer ANN model named GANN, based on watershed geomorphology, was created for long-term daily runoff simulation in a watershed upstream of a reservoir dam. A continuous genetic algorithm (CGA) was utilized for model training. To showcase the GANN model's performance in simulating the precipitation runoff process, the well-known hydrological model HEC-HMS was calibrated as a reference model using daily recorded time series data from the study basin. Geomorphological characteristics of the basin, such as the number of stream orders, average upstream area, and average stream length, were directly incorporated into the ANN structure. The model was trained using a sequence of previous time-step precipitation and runoff as input variables and current flow as the output. The GANN model was applied to predict daily runoff in the Golpayegan watershed, situated in a semi-arid region of Iran. The number of potential flow paths in the watershed determined the number of neurons in the hidden layer of the GANN structure, which remained constant during modeling. Furthermore, the calculated stream path probabilities in this watershed were used as connection weights between the hidden layer and the output in the GANN structure. The findings indicate that utilizing the current time-step of rainfall (Pt) and flow at the previous time-step (Qt-1) as input variables for GANN yields the best performance in simulating daily flow compared to other GANN patterns and the HEC-HMS model. Integrating an ANN model with the geomorphological features of the watershed and an efficient metaheuristic optimization algorithm (e.g., CGA) offers computational efficiency and is suitable for daily runoff simulation in semi-arid regions.

Recent socioeconomic development with associated rapid population growth, urbanization, and industrialization have significantly affected natural landscapes across the world, with various environmental impacts. Land use changes have direct impacts on water resources and ecosystems, both in terms of quantity and quality and the services provided. Such impacts are particularly evident in developing water-scarce areas, where any land use or infrastructure change can significantly stress water quality and ecosystem services (ES). Understanding the complex interactions between land use changes, infrastructure development, water quality, and ES is essential for strategic environmental planning.

We modelled the impacts of intensified urbanization on water quality and ES, in the context of developing regions facing water scarcity conditions. For that purpose, a large, arid, developing area was selected as the case study: the Yongding River Basin (YRB) in North China. The land use changes were modeled and projected through a Cellular Automata Markov model until 2035. The impacts were assessed by i) a comprehensive water quality model considering the discharge of major pollutants in the river network; ii) their spatiotemporal distribution at fine-resolution grid scale; and iii) the economic spatial valuation of the ES. We also account for the real-world environmental policies of the region by considering future infrastructure development, namely the actual planned expansion and efficiency improvement of wastewater treatment (WWT) plants by 2035.

The major pollutants were COD, NH₄⁺, and Total Phosphorus, resulting primarily from urban sources. The efficiency of domestic WWT was found to be a dominant factor in the spatial distribution of future water pollution, but this cannot be the only solution. ES values decrease in the short-term but can increase in the long-term (2035) with the planned WWT expansion.

Our findings have multiple implications for integrated land--water--economic management toward more sustainable development, with targeted interventions to mitigate the environmental impacts.

This study is dedicated to the evaluation of the water surface dynamics of the largest and most important natural lakes in the Republic of Moldova: Manta and Beleu. The lakes' area represents the main natural ecosystem of the country and is a shelter to thousands of animals and plant species which are included in a protected area network. The lakes are situated in the lower Prut floodplain, with main water sources being the river Prut through channels and during floods, as well as groundwater and precipitation. The regulation of the river Prut, climate change and the increasing frequency of droughts and floods have a certain impact on water surface dynamics. The main methods used to evaluate the lakes' extension dynamics are the analysis of satellite images and the application of the NDVI and its variations. The main satellite images used in this study are Landsats, that were identified from 1975 to the present. Thus, the estimation of water surfaces was performed for different decades, and the tendencies were also identified. The increasing magnitude of drought and floods in the last decade influenced the lakes' extension the most. The most recent catastrophic drought in 2022 decreased the surface of Beleu by up to 4 km2 and that of Manta by up to 7,5 km2, while the most recent floods in 2020 flooded up to 30,2 km2 of the area of Beleu and up to 30,4 km2 of that of Manta. The average water surface in recent years is 6,2 km2 for Beleu and 13,4 km2 for Manta.

Urban areas in the Mediterranean are currently some of the areas that are most exposed to the effects of climate change due to flooding. The growing increase in the cold drop episodes (as they were previously referred to), both in intensity and frequency, has generated the so-called DANA phenomena with numerous deaths and considerable economic damage in recent years in countries such as Spain. This requires rethinking flood risk mitigation strategies in these environments, where the traditional approach of constructing hydraulic infrastructures for risk mitigation and flood lamination is, in many cases, economically unaffordable, or even technically impossible. In this context, the implementation of nature-based solutions can be a very interesting approach as an operational tool in the future. However, this should not be approached from a segmented view, but from within the framework of an integrated strategy that combines the diagnosis and subsequent analysis of errors in urban and territorial planning to implement actions that are effective in this matter on a large scale. In this work, various case studies of the Spanish Mediterranean façade subjected to the problems of flooding due to climate change are exposed and analyzed using GIS tools and indicators, proposing various strategies and mitigation actions in relation to the risk of flooding based on the improvement of urban planning and management of the territory as a nature-based solution.

Climate change and over-exploitation are imposing unprecedented threats to groundwater resources. Globally, groundwater reserves have depleted to the extent that well yield has decreased, pumping costs have risen, and land has irreversibly subsided. In Malawi, groundwater quantity is a national problem, specifically in Mzimba district due to severe droughts. In this study, the spatial and temporal trends of groundwater depletion were assessed using Gravity Recovery and Climate Experiment (GRACE) data and Land Surface Models (LSMs) from Global Land Data Assimilation System (GLDAS) and Global Surface Water Explorer (GSWE). The results show the following: 1. Groundwater storage is depleting at an average rate of -1.0 ± 0.06 cm yr^-1 (0.1043 km³yr^-1) in the study area with high rate of up to -1.2 cm yr^-1 (0.12516 km³ yr^-1) in the western side and as low as –0.4 cm yr^-1 (0.04172 km³ yr^-1) in the eastern part. 2. Groundwater storage increases from -13 cm in November up to 15 cm between May and April. 3. Drought is the primary cause of such depletion trends with correlation between active evapotranspiration and groundwater depletion and between downward surface shortwave radiation and groundwater depletion, at -0.577 and -0.678. respectively. The results from this study reveal the need for the scientific community and the general public to consider groundwater recharge strategies specifically by mitigating climate change to reduce prolonged droughts. This study suggests the need to establish a stand-alone groundwater assessment and monitoring authority for enhanced conservation efforts for the water resources in the country.

Parabens, as emerging environmental contaminants, raise significant concerns due to their potential to disrupt microbial ecology and dynamics. Their widespread use and continuous discharge result in their widespread distribution and accumulation in aquatic environments due to their incomplete removal by traditional wastewater treatment processes. Bacterial biofilms in these water systems are continually exposed to parabens, resulting in varied bacterial behaviors and characteristics. This study is the first to assess the changes in the biofilm architecture induced by chlorination and the effect of methylparaben (MP) on colony biofilm architecture and conformation using a Mesolens microscope. For this purpose, 2-day-old Stenotrophomonas maltophilia colony biofilms were grown in R2A agar with MP at environmentally relevant (15 μg/L) and in-use concentrations (15000 μg/L), both with and without free chlorine at 5 mg/L. MP exposure induced noticeable changes in the biofilm structure, such as a denser center and the formation of distinct structures like channels within the colonies. The MP-exposed colony biofilms exhibited more pronounced internal structures, evidenced by a higher number of peaks in the intensity profile. Chlorine disinfection significantly reduced the bacterial growth in the colony biofilms, decreasing the colony diameter by more than half. Additionally, the circularity of the colonies was significantly affected when chlorine and MP were simultaneously present. Furthermore, MP compromised drinking water's disinfection and increased S. maltophilia's tolerance to TMP-SMX, resulting in a 26% decrease in the inhibition halo compared to that for the non-exposed counterparts. These findings suggest that MP, even at environmentally relevant concentrations, can significantly impact the architecture of S. maltophilia colony biofilms, affecting their tolerance to chlorine and antibiotics.

Coastal lagoons, characterized by their rich biodiversity and productivity, play a vital role in ecosystem services such as climate regulation, food production, etc. Since they have limited water exchanges and long hydraulic retention times, they are ecosystems highly vulnerable to anthropogenic factors and the accumulation of pollutants. In this study, we aimed to investigate the impact of Hydrogen Sulphur (H₂S) concentration and salinity infusion on the community diversities of bacteria, phytoplankton and zooplankton of a hypereutrophic coastal lagoon, Küçükçekmece Lagoon, located in Istanbul (Türkiye). Surface water samples were collected from three sites, along with samples from various depths (surface, 9 m and 18 m) throughout the water column in June 2022. The bacterial community structures were assessed by 16S rRNA gene-targeted sequencing using MinION (ONT), and phytoplankton and zooplankton diversities were analysed by microscopy. The results showed that the communities in the surface waters and the middle layer of the lagoon were quite similar. However, there was a clear shift in the community structure of the samples collected from the deepest part (18 m), which was under anoxic and high salinity conditions. The bacterial community was predominated by Sulfurimonas (15%), Sulfurovum (7%), and Draconibacterium, (7%) which can be related to the anoxic conditions and high H₂S concentration (20.39 mg/L). The results revealed that the responses of phytoplankton and zooplankton communities to the salinity increase were significant. Dominant phytoplankton, Cylindrotheca closterium, and dominant zooplankton, Acartia clausii, found in the deeper layer with high salinity are generally known as indicators of marine pollution. Although there were historical data on physicochemical properties and zooplankton and phytoplankton community diversities in this lagoon, this research provides the first extensive examination of such community structures, including the bacterial community of this lagoon, and lays the groundwork for future research in this aquatic ecosystem.

Urban Drainage Systems (UDSs) have existed since the Babylonian Empire. Their objective is to preserve and promote public health, welfare, and flood protection and avoid water pollution. Population and urbanization growth, climatic change, and aging structures are the main factors to produce failures in sewer systems due to the increase in surface runoff induced by changes in land use and land cover. The consequence is urban flood hazards. Therefore, in this research, a methodologic framework was developed to assess the hydraulic performance of a UDS in a pilot basin situated in Quito, Ecuador. By using three kinds of information, spatial, temporal, and terrain, a number of products were generated, such as design rainfall, historical precipitation, dry weather flows and their patterns, a topological network, land uses, a DTM, a DSM, and an orthophoto, and subsequently, a hydrodynamic 1D model was built by using a PCSWMM model. Calibration and validation of the model was carried out by employing hydrometeorological data that were registered in ultrasonic sensors to measure the depth and velocity of the flow every minute and a gauge station, which were implemented in the study area from January to October 2023. To evaluate the goodness of fit, the ISE, NSE, R2, LSE, and RMSE were employed, whose values were within the recommend ranges. The results of this framework could provide support to decision makers to come up with the optimal rehabilitation measures, which could be gray, green, or hybrid,with a combination of these infrastructures, to minimize flood risk and improve the level of service of this important sanitary infrastructure.