Search Results (568)

Wet areas, which are locations in the landscape that consistently retain moisture, and channel networks are important landscape compartments, with key hydrological and ecological functions. Hence, defining their spatial boundaries is an important step towards sustainable watershed management. In catchments of developing countries, wet areas and small order channels of river networks are rarely mapped, although they represent a crucial component of local livelihoods and ecosystems. In this study, topographic attributes generated with a 30 m SRTM DEM were used to map wet areas and stream networks of two tropical catchments in Central Brazil. The topographic attributes for wet areas were the local slope and the slope curvature, and the Topographic Wetness Index (TWI) was used to delineate the stream networks. Threshold values of the selected topographic attributes were calibrated in the Santa Maria catchment, comparing the synthetically generated wet areas and drainage networks with corresponding reference (map) features, and validated in the nearby Santa Maria basin. Drainage network and wet area delineation accuracies were estimated using random basin transects and multi-criteria and confusion matrix methods. The drainage network accuracies were 67.2% and 70.7%, and wet area accuracies were 72.7% and 73.8%, for the Santa Maria and Gama catchments, respectively, being equivalent or higher than previous studies. The mapping errors resulted from model incompleteness, DEM vertical inaccuracy, and cartographic misrepresentation of the reference topographic maps. The study’s novelty is the use of readily available information to map, with simplicity and robustness, wet areas and channel initiation in data-scarce, tropical environments. Full article

This paper presents the Green Watershed Index (GWI) methodology, focusing on the 17 sustainability indicators selected in the Razey watershed, NW Iran. Field surveys and data collection have provided the possibility of field inspection and measurement of the present condition of the watershed and the indicators taken. Based on the degree of compliance with the required process, each indicator was scored from 0 to 10 and classified into three categories: unsustainable, semi-sustainable, and sustainable. Using the Entropy method to assign weight to each indicator and formulating a proportional mathematical relationship, the GWI score for each sub-watershed was derived. Spatial changes regarding the selected indicators and, consequently, the GWI were detected in the study area. Development of water infrastructure, particularly in the upstream sub-watersheds, plays a great role in increasing the GWI score. The highest weight is related to environmental productivity (0.26), and the five indicators of water footprint, knowledge management and information quality system, landscape attractiveness, waste recycling, and corruption control have approximately zero weight due to their monotonous spatial distribution throughout sub-watersheds. Only sub-watershed R1 has the highest score (5.13), indicating a semi-sustainable condition. The rest of the sub-watersheds have unsustainable conditions (score below 5). Concerning the GWI, the watershed is facing a critical situation, necessitating the implementation of management and conservation strategies that align with the sustainability level of each sub-watershed. Full article

Watershed ecosystem resilience (RES) plays a vital role in supporting ecosystem sustainability. However, comprehensive assessments and investigations into the complex mechanisms driving RES remain limited, particularly in ecologically sensitive basins. To address this gap, this study proposes a multidimensional RES evaluation framework tailored to watershed-specific natural characteristics. The framework integrates five core dimensions: ecosystem resistance, ecosystem recovery capacity, ecosystem adaptability, ecosystem services, and ecosystem vitality. RES patterns under 2030 different future scenarios were simulated using the PLUS model combined with CMIP6 climate projections. Spatial and temporal dynamics of RES from 2010 to 2020 were quantified using Geodetector and Partial Least Squares Path Modeling, offering insights into the interactions among natural and anthropogenic drivers. The results reveal that RES in the Upper Yangtze River Basin exhibits a spatial gradient of “high in the east and west, low in the middle” with an overall 2.80% decline during the study period. Vegetation coverage and temperature emerged as dominant natural drivers, while land use change exerted significant indirect effects by altering ecological processes. This study emphasizes the importance of integrated land-climate strategies and offers valuable guidance for enhancing RES and supporting sustainable watershed management in the context of global environmental change. Full article

The rising demand for freshwater, driven by population growth, economic development, and climate change, necessitates proactive watershed management. This study focuses on prioritizing the watersheds of the Doon Valley in the Indian Himalayan Region (IHR) using geospatial techniques. It involves a detailed morphometric analysis incorporating hydrological and topographical parameters, ranking the watersheds using the compound factor value (CFV), and prioritizing them based on the given CFV. The Doon Valley watersheds exhibit dendritic to parallel drainage patterns and moderate relief. The study identifies the Suswa watershed as the most susceptible, necessitating urgent conservation attempts to mitigate soil erosion and ensure sustainable land use. In contrast, the Song watershed, characterized by steep slopes and high relief, requires targeted management strategies to control rapid runoff and prevent potential flooding. The Asan watershed, with a medium priority classification, also requires intervention to prevent ecological degradation. Prioritization based on the CFV provides a strategic framework for targeted management, offering valuable insights for policymakers and planners. This research supports sustainable watershed management by guiding effective conservation practices and addressing the specific needs of each watershed. Full article

As an ecological transition zone, the ecosystem of the Qin River Basin in the middle reaches of the Yellow River is of great significance to the regional ecological balance. With the rapid socio-economic development, land use changes are significant, and the spatial and temporal patterns of ecosystems are evolving. Exploring its dynamics and driving mechanisms is crucial to the ecological protection and sustainable development of watersheds. This research systematically examines the spatiotemporal dynamics and driving mechanisms of ecosystem patterns in the middle Yellow River’s Qin River Basin (1990–2020). Quantitative assessments integrating ecosystem transition metrics and redundancy analysis reveal three critical insights: (1) dominance of agricultural land and woodland (74.81% combined coverage), with grassland (18.58%) and other land types (6.61%) constituting secondary components; (2) dynamic interconversion between woodland and grassland accompanied by urban encroachment on agricultural land, manifesting as net reductions in woodland (−13.74%), farmland (−6.60%), and wetland (−38.64%) contrasting with grassland (+43.34%) and built-up area (+116.63%) expansion; (3) quantified anthropogenic drivers showing agricultural intensification (45.03%) and ecological protection measures (36.50%) as primary forces, while urbanization account for 18.47% of observed changes. The first two RDA ordination axes significantly (p < 0.01) explain 68.3% of the variance in ecosystem evolution, particularly linking land-use changes to socioeconomic indicators. Based on these findings, the study proposes integrated watershed management strategies emphasizing scientific land-use optimization, controlled urban expansion, and systematic ecological rehabilitation to enhance landscape stability in this ecologically sensitive region. The conclusions of this study have important reference value for other ecologically sensitive watersheds in land use planning, ecological protection policy making, and ecological restoration practice, which can provide a theoretical basis and practical guidance. Full article

Green roofs (GRs) are emerging as effective tools for mitigating urban runoff, particularly in cities facing challenges related to increased impervious surfaces and flooding risks. This study evaluates the potential hydrological performance of GR retrofitting in São José dos Campos, Brazil, based on municipal legislation, focusing on the effects of reducing the Effective Impervious Area (EIA) in urban watersheds. Using a range of projected EIA reduction scenarios (Mandatory, Incentivized, and Ideal), this study compares key hydrological indicators such as peak flow attenuation, runoff volume reduction, and hydrograph delay during rainfall events with different return periods. The results show that retrofitting with GRs significantly attenuates peak flows and delays runoff, with the ‘Ideal’ scenario (EIA = 16%) achieving peak flow reductions of up to 41% and runoff volume reductions of 35%. However, the effectiveness of GRs diminishes for high-intensity rainfall events, suggesting that GRs are most effective for frequent, low-intensity storms. These findings demonstrate the potential of GRs in reducing flooding risks in urban environments, highlighting the importance of integrating GRs into broader sustainable drainage systems. This study further emphasizes that while financial support is crucial for promoting GR adoption, it alone is not sufficient. Policies should be complemented by educational efforts and urban regulatory measures to ensure widespread adoption and long-term impact. This research provides urban planners and stakeholders with evidence to enhance urban resilience, sustainability, and effective flood risk management. Full article

Utah, USA, relies heavily on snowpack for water to sustain its growing population. Scientists and policy makers are exploring and proposing several potential sustainable solutions to improving flow to the Great Salk Lake as it recently has significantly declined in size, including removing tree canopy. This study examines the influence of tree canopy coverage, climate, and topography on snow water equivalent (SWE) within the Great Salt Lake Watershed. Using SNOTEL data, NLCD land use/land cover rasters, t-tests, and multiple linear regression (MLR), the study analyzed SWE variability in relation to canopy density, winter precipitation, elevation, temperature, and latitude. Initial t-tests showed significant differences in SWE between sites with canopy coverage below and above 70%, yet tree canopy was excluded as a significant predictor in the MLR model. Instead, SWE was primarily explained by mean winter precipitation, elevation, average winter high temperatures, and latitude. Additionally, canopy change analysis of the 2018 Pole Creek Fire in the Jordan River watershed showed no significant changes in SWE following canopy loss. This study highlights the dominant role of climatic factors in influencing snowpack dynamics on a watershed scale. It also provides important data for sustainable watershed and forestry management and a framework for understanding snowpack responses to climate and land cover changes in saline lake ecosystems. Full article

Industrial and urban activity has inevitably changed the water environment and caused significant impacts on water resources’ quality and quantity. The identification of related impacts is particularly important in the context of increasing water shortages due to climate change. Overlapping industrial impacts and drought occurrence have resulted in the long-lasting deterioration of surface water status. Therefore, the mitigation of negative impacts is crucial for relevant and sustainable water management in river basins. One of the most impactful branches of industry is underground coal mining, which requires dewatering deposits and excavations. Mine waters discharged into rivers have induced significant increases of salinity, while urban wastewaters have increased biogenic contamination in surface waters. Sustainable development goals require water protection, energy transition, and circularity; therefore, coal will be repurposed in favor of alternative sources of energy. The phasing out of coal and cessation of dewatering of mines would rapidly reduce mine waters’ impact on the environment. However, in heavily industrialized urban basins, the share of natural waters in river flows is exceptionally low—due to significant and long-lasting transformations, industrial and urban wastewaters are the main constitutive components in certain river hydrological regimes. The case study of Bytomka in the Upper Silesian Coal Basin, Southern Poland is a vivid example of a river basin significantly impacted by urban and industrial activity over a long-term period. The Bytomka River’s water status and the development of its watershed area is an example of complex and overlapping impacts, wherein sustainable water management requires proper recognition of prevailing factors such as mine water discharges, climate change and drought periods, wastewater impacts, and urbanization of the water basin area. The presented study reveals key findings showing that future coal mine closures would result in significant water resource shortages due to a reduction of mine water discharges, significant biogenic (N and P) pollution increases, and hazards of harmful algal blooms. Therefore, there is an urgent need to increase the retention potential of the watershed, use nature-based solutions, and mitigate negative impacts of the coal mining transition. The increase in treatment capability of industrial wastewater and sewage discharge would help to cope with the natural water vulnerability induced by the impacts of climate change. Full article

Anthropogenic pollution of watersheds significantly threatens aquatic ecosystems, biodiversity, and human health. The present review examines the primary sources of contamination in river catchments, including industrial effluents, agricultural runoff, and urban wastewater discharge. The presence of pollutants degrades water quality, disrupting aquatic habitats and leading to adverse outcomes, including biodiversity loss, eutrophication, and declining fish populations. It also focuses on strategic mitigation approaches, including implementing stricter waste management regulations, adopting sustainable agricultural practices, improving wastewater treatment infrastructure, and public education initiatives. The article summarizes several biotechnological techniques developed to decrease the impact of farming activities on water quality. It also emphasises directions that could be followed concerning specific water chemical indicators, such as the residual quantity of heavy metals. Emphasis is placed on the need for integrated policy frameworks and cross-sector collaboration to safeguard freshwater systems and ensure long-term environmental sustainability. Full article

Under the global urbanization context, irrational land use patterns have exacerbated ecosystem imbalance. Developing watershed ecological risk assessment methods based on adaptive cycle theory holds significant scientific importance for flood risk prevention. This study established a watershed ecological risk assessment framework within the adaptive cycle framework, focusing on the Poyang Lake Ecological Economic Zone in the middle-lower Yangtze River Basin. The results revealed that high-risk ecological areas clustered around the Poyang Lake water system with scattered urban distribution, while medium-risk zones dominated the study area. Low-risk regions primarily concentrated in the Yuanhe Plain of southwestern region. The system exhibited significant spatial heterogeneity in “exposure” and “disturbance” risks. Medium–high exposure pixels accounted for 43.3% with a dispersed distribution, whereas disturbance pixels concentrated in Poyang Lake waters and developed urban areas (64.34%), indicating that disturbance exerted a stronger influence on risk assessment outcomes. Governance practices demonstrated that policy preferences may introduce biases into watershed ecological risk evaluations. Multi-scenario simulations using an Ordered Weighted Averaging (OWA) algorithm identified risk-uncertain zones in southeastern hilly areas and northern Poyang Lake waters, while distinguishing stable high/low-risk regions unaffected by decision-making influences. These findings provide critical references for formulating sustainable watershed management strategies. Full article

Groundwater is a critical freshwater resource, yet its quality is increasingly threatened by anthropogenic activities, particularly in urbanized regions. This study employs geospatial analysis to evaluate the spatiotemporal variability of groundwater quality across 11 Watershed Management Areas (WMAs) in northern New Jersey, from 1999 to 2016. Using specific conductance (SC) as a proxy for salinity, we applied Ordinary Kriging interpolation to estimate SC values in unmonitored locations, leveraging data from 295 shallow wells within the New Jersey Ambient Groundwater Quality Monitoring Network. The results reveal significant spatial heterogeneity in groundwater quality, strongly associated with land use and road density. The Northeast water region, characterized by high urbanization and extensive road networks, exhibited the poorest water quality, with salinity levels exceeding the 750 μS/cm threshold for freshwater in WMAs such as Lower Passaic (WMA-4) and Hackensack (WMA-5). In contrast, the Northwest region, dominated by agricultural and undeveloped land, maintained better water quality. Temporal analysis showed a worrying decline in freshwater coverage, from 80% in 1999–2004 to 74% in 2014–2016, with deicing salts and aging sewer infrastructure identified as major contamination sources. The study highlights the efficacy of Kriging and GIS tools in mapping groundwater quality trends and highlights the urgent need for targeted water management strategies in vulnerable regions. These findings provide policymakers and stakeholders with actionable insights to mitigate groundwater degradation and ensure long-term freshwater sustainability in northern New Jersey. Full article

Sustaining instream flows is becoming increasingly critical due to the combined pressure of climate change and intensive reservoir operations in multi-dam watersheds. This study evaluates instream flow sustainability in the Seomjin River basin by integrating the SWAT and K-WEAP models with CMIP6-based climate scenarios. Two contrasting dam operation strategies—firm and deficit supply—were assessed over multiple temporal scales, including hydrological seasons and agricultural activity. Sustainability was quantified using the Sustainability Index (SI), which integrates reliability, resilience, and vulnerability. The probabilistic assessment revealed that the relative performance of the two strategies varied depending on the season and flow conditions. The firm supply generally exhibited higher sustainability under drought and low-demand periods, effectively reducing the probability of unsustainable outcomes. In contrast, the deficit supply often achieved higher sustainability under wet conditions or peak agricultural demand, although it was occasionally linked to extremely low SI values. These findings underscore the importance of season-specific, risk-informed dam operation planning over reliance on a single strategy and emphasize the need for flexible management frameworks capable of responding to diverse hydrological futures. Full article

Continuous use of agricultural chemicals and fertilizers, sporadic sewer overflow events, and an increase in urbanization have led to significant nutrient/pollutant loadings into the semi-arid Arroyo Colorado River basin, which is located in South Texas, U.S. Priority nutrients that require reduction include phosphorus and nitrogen and to mitigate issues of low dissolved oxygen, in some of its river segments. Consequently, the river’s potential to support aquatic life has been significantly reduced, thus highlighting the need for restoration. To achieve this restoration, a watershed protection plan was developed, comprising several preventive mitigation measures, including installing green infrastructure (GI) practices. However, for effective reduction of excessive nutrient loadings, there is a need to study the effects of different combinations of GI practices under current and future land use scenarios to guide decisions in implementing the cost-effective infrastructure while considering factors such as the existing drainage system, topography, land use, and streamflow. Therefore, this study coupled the Soil and Water Assessment Tool (SWAT) model with the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) model to determine the effects of different combinations of GI practices on the reduction of nitrogen and phosphorus under changing land use conditions in three selected Arroyo Colorado subwatersheds. Two land use maps from the U.S. Geological Survey (USGS) Forecasting Scenarios of land use (FORE-SCE) model for 2050, namely, A1B and B1, were implemented in the coupled SWAT-SUSTAIN model in this study, where the urban area is projected to increase by 6% and 4%, respectively, with respect to the 2018 land use scenario. As expected, runoff, phosphorus, and nitrogen slightly increased with imperviousness. The modeling results showed that implementing either vegetated swales or wet ponds reduces flow and nutrients to meet the Total Maximum Daily Loads (TMDLs) targets, which cost about USD 1.5 million under current land use (2018). Under the 2050 future projected land use changes (A1B scenario), the cost-effective GI practice was implemented in vegetated swales at USD 1.5 million. In contrast, bioretention cells occupied the least land area to achieve the TMDL targets at USD 2 million. Under the B1 scenario of 2050 projected land use, porous pavements were most cost effective at USD 1.5 million to meet the TMDL requirements. This research emphasizes the need for collaboration between stakeholders at the watershed and farm levels to achieve TMDL targets. This study informs decision-makers, city planners, watershed managers, and other stakeholders involved in restoration efforts in the Arroyo Colorado basin. Full article

This study aimed to analyze changes in water retention conservation in response to climate change and forest management strategies and to propose methods for securing sustainable water resources. The KO-G-Dynamic model, a Korean forest growth model, was utilized alongside aboveground and belowground water resource prediction models to evaluate changes in water retention conservation under various climate change scenarios and forest management strategies. The analysis revealed that under climate change and current forest management levels, water retention conservation was projected to reach 37.553 billion tons per year in the 2030s, 38.274 billion tons per year in the 2050s, and 40.306 billion tons per year in the 2080s. Under optimal forest management policies, the water yield and storage were expected to increase to 37.863 billion tons per year in the 2030s, 38.877 billion tons per year in the 2050s, and 41.495 billion tons per year in the 2080s. Notably, watershed-based forest management offers a more practical management unit than conventional legal boundaries, as it reflects hydrological flow and the ecological characteristics of forest environments. Furthermore, the watershed-based forest management scenario demonstrated greater feasibility in securing water resources. This study provides foundational data for climate change adaptation and sustainable forest management and may aid national and local forest planning. The findings underscore the critical role of forest management in mitigating climate change impacts and ensuring long-term water sustainability. Full article

Accurate runoff simulation and prediction are crucial for water resources management, especially under the impact of climate change. In this study, a multi-physics ensemble Bayesian model averaging (MPE-BMA) model is developed to improve runoff prediction accuracy by integrating a soil and water assessment tool (SWAT), hydrologiska byråns vattenbalansavdelning (HBV) model, and Bayesian model averaging (BMA) into a general framework. The MPE-BMA model integrates the strengths of the SWAT and HBV models. This approach enhances the robustness of simulation outputs and reduces uncertainties from single-model methods. MPE-BMA is subsequently employed to simulate and predict runoff for the upper reaches of Xiangxi River Basin (XXRB) in China, where four general circulation models (GCMs) and three shared socioeconomic pathways (SSP126, SSP245, and SSP585) are considered. Multiple statistical metrics (R², NSE, and RMSE) prove that the MPE-BMA model outperforms the single models of SWAT and HBV. Results reveal that higher-emission scenarios generally lead to significant decreases in runoff, particularly by the 2080s. Specifically, under SSP585, runoff is projected to decrease by approximately 4.61–12.68% by the 2040s and 5.96–11.28% by the 2080s compared to the historical period. From the perspective of monthly and seasonal runoff changes, the peak runoff is projected to shift from June to May by the 2080s. Additionally, under SSP585, spring and summer runoffs tend to significantly increase, while winter runoff decreases sharply, leading to wetter summers and drier winters. These findings underscore the importance of enhancing water use efficiency, upgrading hydropower stations, and implementing watershed management practices to ensure sustainable water resources management in the XXRB amidst climate change. Full article