Regional Water Security Research Articles

Risk assessment and sources associated with potentially toxic elements in suspended particulate matter: A karst river perspective in active mining area

Study regionDaiyang River Basin, a typical karst river basin impacted by mining activities in Guizhou, Southwest China. Study focusRivers are fundamental components of regional water security, but they are facing potentially toxic elements (PTEs) pollution caused by mining activities. This study investigated the concentration, behavior, risks and sources of nine PTEs in suspended particulate matter (SPM) from mining-impacted karst rivers, which are essential for the safety and management of karst water environments. New hydrological insights for the regionThe contents of Cr, Ni, Cu, Zn, As, Cd, Sb and Hg exceeded the corresponding local soil background values, with Zn and Cu being the most important pollutants. These elements caused a very high potential toxicity risk to the basin and unacceptable carcinogenic and non-carcinogenic risks to the local residents. Correlation analysis and the positive matrix factorization (PMF) model indicated that Ni, Cd, Zn and Cu were mainly derived from mixed sources of geological background and anthropogenic activities (30.95 %), Hg, Sb, and As were related to coal mining and combustion sources (28.91 %), while Pb, As, Cr and Sb were mainly contributed by natural sources (40.15 %). Furthermore, mixed sources, mining-related sources and As were identified as priority control factors in the study area. These insights can provide powerful support for decision-makers to develop control policies and reduce PTEs pollution in karst areas.

Changes of blue and green water in arid inland dissipation area based on coupled surface water and groundwater model

Study regionThe Mainstream in the Tarim River Basin, Southern Xinjiang, China Study focusClimate change and human activities have significantly altered the water cycle, and water security evaluation and management are urgent. In arid and semi-arid areas, the assessment of blue and green water is particularly important. In this study, the MIKE SHE model is used to simulate the spatial and temporal changes of blue and green water resources in the mainstream of the Tarim River Basin (TRB) from 1990 to 2050 under land use and climate change conditions. The scarcity and vulnerability of blue-green water are introduced to evaluate the water security of the basin. The impacts of different land uses on blue-green water resources were also calculated according to the model zoning. New hydrological insights for the regionThe results indicate that from 1990 to 2050, blue water resources show a spatial pattern of gradual decrease from upstream to downstream. Compared to blue water, green water is dispersed more evenly over space. Future climatic scenarios will impact water security, as will changes in blue and green water security in terms of time and space. By comparing the influence of ecological water transport on the change of blue and green water before and after 2000, it was found that environmental water transport plays a certain role in improving the blue water scarcity in downstream of the TRB. The study is significant in maintaining regional water security and ecosystem stability.

Water resource management and policy evaluation in Middle Eastern countries: Achieving sustainable development goal 6

This study explores the challenges and management strategies of water resources in 15 Middle Eastern countries, framed within the context of Sustainable Development Goal 6 (SDG6). This study used 123 water resource policies in Middle Eastern countries as data and employed a pre-trained large language model based on RoBERTa, trained on the SNLI and MNLI datasets, to perform text classification tasks. In combination with the TF-IDF algorithm for keyword extraction, this approach is used to systematically evaluate and compare the water resource policies of these countries. The results reveal that the region faces significant water stress, exacerbated by high population growth, climate variability, and political instability. While countries like Kuwait and the UAE utilize advanced desalination technologies to mitigate water scarcity, policy gaps in sanitation and transboundary cooperation persist. Jordan's innovative partnerships for water resource management highlight the potential of collaborative frameworks to enhance regional water security. The findings suggest that comprehensive water management strategies, including technological innovation and public-private partnerships, are essential for addressing the region's pressing water challenges. This research contributes to understanding the complexities of water governance in arid regions and offers practical implications for policymakers aiming to achieve sustainable water resource management.

Achieving water security in India through sustainable wastewater reuse: The roles of policy, politics, and people

This study investigates the challenges and strategies associated with successfully implementing the Koramangala-Challaghatta Valley project in Karnataka, India. This project is an innovative approach for water security in semi-arid regions by indirectly recharging groundwater using treated wastewater. Interviews with various stakeholders reveal strategies to address key challenges. An integrated wastewater management and safe reuse framework were applied to analyze the qualitative data. This study highlights the effectiveness of an integrated approach, including institutional collaboration with policies/programs to address technical, financial, and risk mitigation aspects, while community participation promotes social acceptance and ensures the long-term sustainability of wastewater reuse initiatives.

Mass Balance of Maritime Glaciers in the Southeastern Tibetan Plateau during Recent Decades

Maritime glaciers in the southeastern Tibetan Plateau (SETP) are particularly sensitive to changes in climate, and their changes directly and severely affect regional water security and glacier-related hazards. Given their large societal importance, a better understanding of the mass balance of maritime glaciers in the SETP, a key variable for characterizing the state of glacier health, is of great scientific interest. In this review, we synthesize in situ, satellite-based observations and simulations that present an overall accelerating negative mass balance of maritime glaciers in the SETP in recent decades. We hereby highlight a significant spatiotemporal difference in the mass balance of maritime glaciers across the SETP and investigate the drivers of the accelerated mass loss of these glaciers in recent years. We find that accelerated glacier mass loss agrees with the variabilities in temperatures rising and precipitation decreasing at regional scales, as well as the spatial patterns of widespread melt hotspots (e.g., thin debris, ice cliffs, supraglacial ponds, and surface streams), the expansion of glacial lakes, enlarged ice crevasses, and frequent ice avalanches. Finally, the challenges of the mass balance study of maritime glaciers and future perspectives are proposed. Our review confirms the urgent need to improve the existing glacier inventory and establish comprehensive monitoring networks in data-scarce glacierized catchments, and it suggests paying particular attention to the development of glacier mass-balance models that coupe multiple physical processes at different interfaces to predict the status of maritime glaciers and their responses to climate change. This study can inform the sustainable management of water resources and the assessment of socio-economic vulnerability due to glacier-related hazards in the SETP and its surroundings in the context of marked atmospheric warming.

Antibiotic resistome dynamics in agricultural river systems: Elucidating transmission mechanisms and associated risk to water security

Usage of antibiotics in agriculture has increased dramatically recently, significantly raising the influx of antibiotic resistance genes (ARGs) into river systems through organic manure runoff, seriously threatening water security. However, the dynamics, transmission mechanisms, and potential water security risk of ARGs, as well as their response to land use spatial scale and seasonal variations in agricultural river systems remain unclear. To address these challenges, this work employed metagenomic technique to systematically evaluate the pollution and dissemination of ARGs in overlying water and sediment within a typical agricultural catchment in China. The results demonstrated significant differences between overlying water and sediment ARGs. Overlying water dominated by multidrug ARGs exhibited higher diversity, whereas sediment predominantly containing sulfonamide ARGs had higher abundance. The dynamics of ARGs in overlying water were more responsive to seasonal variations compared to sediment due to greater changes in hydrodynamics and nutrient conditions. The profiles of ARGs in overlying water were largely regulated by microbiota, whereas mobile genetic elements (MGEs) were the main forces driving the dissemination of ARGs in sediment. The variation in dissemination mechanisms led to different resistance risks, with sediment presenting a higher resistance risk than overlying water. Furthermore, Mantel test was applied to discover the impact of land use spatial scale and composition on the transmission of ARGs in river systems. The findings showed that cultivated land within 5 km of the riverbank was the key influencing factor. Cultivated land exacerbated ARGs spread by increasing MGEs abundance and nutrient concentrations, resulting in the abundance of ARGs in high-cultivated sites being twice that in low-cultivated sites, and raising the regional water security risk, with a more pronounced effect in sediment. These findings contribute to a better understanding of ARGs dissemination in agricultural watersheds, providing a basis for implementing effective resistance control measures and ensuring water security.

Waters of Contention: The GERD and Its Impact on Nile Basin Cooperation and Conflict

The Grand Ethiopian Renaissance Dam (GERD) on the Nile River has become a focal point in the fields of water diplomacy, economics, and environmental considerations in the Nile Basin. Announced during the Arab Spring in 2011, the GERD aims to address Ethiopia’s significant energy shortfall and foster regional economic growth by potentially doubling the country’s electricity output. However, this ambition has heightened tensions with downstream countries, especially Egypt and Sudan, which rely heavily on the Nile for their water needs. This paper examines the ongoing conflict surrounding the GERD, focusing on the deadlock situation despite considerable scholarly attention to its economic, political, and environmental dimensions. The analysis presented in this paper reveals the roots of contention by analyzing past treaties and the present negotiation status, illustrating the complex interplay between development goals, environmental sustainability, and regional water security. The paper advocates for a revised legal framework that moves beyond past agreements towards a more inclusive, cooperative management strategy for the Nile’s waters. It proposes the development of a new treaty between Egypt, Ethiopia, and Sudan, grounded in their 2015 Declaration of Principles agreement and inspired by successful international dispute resolutions. It also discusses the potential of neutral third-party interventions to facilitate unbiased negotiations grounded in the Graph Model for Conflict Resolution, emphasizing the importance of equitable and sustainable water governance. In essence, this research calls for a collaborative approach to resolve the GERD conflict, emphasizing the need for agreements that harmonize developmental ambitions with the water security of the Nile Basin nations. .

Observed changes in the climate and snow dynamics of the Third Pole

The Third Pole (TP) is the world’s largest highland and has one of the biggest reservoirs of glacier ice mass and snow cover on the Earth. Three major Asian rivers (the Indus, Ganga and Brahmaputra) are nourished by the melting of glaciers and snow in Central Himalaya, which are inevitable for the socioeconomic sustainability and water security of South Asia. Here, we investigate the long-term (1980–2020) changes in snow depth and precipitation in TP, where major precipitation occurs in the form of rainfall in summer, and snowfall in winter and spring. The seasonal mean snow depth is deep (≥1 m) in winter and shallow (≤0.2 m) in summer. The average snowmelt and snow water equivalent are higher in the central and western Himalaya and Karakoram ranges in spring, which are the regions with most glaciers in TP. There is a significant positive trend in total precipitation, about 0.01–0.03 mm d−1 yr−1 in the central and eastern TP during the South Asian Summer Monsoon for the 1980–2020 period. Snowmelt is also increasing (>0.5 × 10−3 mm yr−1) in the western Himalaya during spring, which is consistent with the temperature rise (0.04–0.06 °C yr−1) there. In addition, there is a notable increase in the annual mean glacier melt (here, the water equivalent thickness) in TP (−1 to −5 cm w.e. yr−1), with its highest values in the eastern and central Himalaya (−3 to −5 cm w.e. yr−1), as estimated for the period 2003–2020. On top of these, by the end of the 21st century, the Coupled Model Intercomparison Project Phase 6 (CMIP6) projections show that there would be a significant decrease in snow depth and an increase in temperature of TP in all shared socioeconomic pathways (SSPs). Henceforth, the increasing trend in temperature and melting of snow/glaciers in TP would be a serious threat to the regional climate, water security and livelihood of the people of South Asia.

A Deep Learning‐Based Data Assimilation Approach to Characterizing Coastal Aquifers Amid Non‐Linearity and Non‐Gaussianity Challenges

AbstractSeawater intrusion (SI) poses a substantial threat to water security in coastal regions, where numerical models play a pivotal role in supporting groundwater management and protection. However, the inherent heterogeneity of coastal aquifers introduces significant uncertainties into SI predictions, potentially diminishing their effectiveness in management decisions. Data assimilation (DA) offers a solution by integrating various types of observational data with the model to characterize heterogeneous coastal aquifers. Traditional DA techniques, like ensemble smoother using the Kalman formula (ESK) and Markov chain Monte Carlo, face challenges when confronted with the non‐linearity, non‐Gaussianity, and high‐dimensionality issues commonly encountered in aquifer characterization. In this study, we introduce a novel DA approach rooted in deep learning (DL), referred to as ESDL, aimed at effectively characterizing coastal aquifers with varying levels of heterogeneity. We systematically investigate a range of factors that impact the performance of ESDL, including the number and types of observations, the degree of aquifer heterogeneity, the structure and training options of the DL models. Our findings reveal that ESDL excels in characterizing heterogeneous aquifers under non‐linear and non‐Gaussian conditions. Comparison between ESDL and ESK under different experimentation settings underscores the robustness of ESDL. Conversely, in certain scenarios, ESK displays noticeable biases in the characterization results, especially when measurement data from non‐linear and discontinuous processes are used. To optimize the efficacy of ESDL, attention must be given to the design of the DL model and the selection of observational data, which are crucial to ensure the universal applicability of this DA method.

Advancing water security in arid regions: A technological and bibliometric study on integrating hydro panels in buildings for sustainable development goals

Water scarcity poses a critical global challenge, especially in arid and semi-arid regions. This paper introduces an innovative nexus approach to mitigate this issue through the integration of hydro panels in buildings, exploiting solar energy and atmospheric humidity to generate clean water. We offer a comprehensive review of the hydro panel technology's current state, exploring its potential, implementation challenges, and alignment with Sustainable Development Goals (SDGs) through a bibliometric analysis. Our findings highlight a significant uptick in research on sustainable building technologies, positioning hydro panels at the nexus of solutions for water scarcity. Despite their promise, our analysis reveals a scarcity of focused research on hydro panels, indicating an emerging interest in leveraging smart city frameworks for environmental sustainability. The paper contributes by defining the technological trajectory and identifying gaps in existing research, emphasizing the hydro panels' potential to transform water accessibility in arid regions, especially when integrated with other sustainable technologies such as solar photovoltaic (PV) systems. This review not only underlines hydro panels as a novel solution but also paves the way for future investigations into their broader application within the nexus of sustainable urban development.

Decarbonizing Water: The Potential to Apply the Voluntary Carbon Market toward Global Water Security.

The increase in global water insecurity is one of the first perceivable effects of climate change. Two billion people are now without access to safe drinking water, and four billion experience water stress at least once a year, primarily in low per-capita emission countries. This nexus between climate change and water insecurity has significant implications for the global economy, with the water sector contributing 10% of global emissions. Though traditionally a local issue, climate finance mechanisms like the voluntary carbon market (VCM) present opportunities for a global, sustainable, performance-based funding stream to address water insecurity. Since 2010, water-related carbon projects have yielded over 45 million emission reduction credits. Our analysis estimates a global potential of over 1.6 billion tCO2e per year across various water project subsectors. At a $10 per credit average, this could attract over $160 billion in investments over the next decade, enhancing global water security. However, barriers like high intervention costs and limited technologies hinder widespread implementation, creating a tension between standardized and bespoke credits. We present case studies, spanning drinking water initiatives to the wastewater treatment sector that illustrate VCM's role in channeling private sector capital for water security in climate-vulnerable regions.

Exploring Leadership approaches of Women in Climate Justice: Pathways to Impact and Empowerment

This paper will examine the role of women in promoting peace through leadership in the climate justice space; through building an inclusive climate movement to tackle the triple planetary crisis facing the globe. Studies reflect that marginalised populations are disproportionately affected by climate change and environmental degradation, particularly indigenous communities and women, despite contributing the least to climate catastrophe. Women are among the 32.6 million climate migrants and refugees each year, who are in turn, at risk of experiencing gender-based violence. Standing at the frontlines of the triple planetary crisis, women are ideally placed to take up leadership roles within efforts toward achieving climate justice and a sustainable future. Women serve as primary caregivers, often responsible for providing food and water security, sustaining families and households in climate-affected regions. They are the first guardians and caretakers of our youth, possessing the necessary emotional depth, compassion, and maternal instinct to promote the values underpinning climate justice, which at its core, advocate for the sustenance of Mother Earth through an empathetic lens. Women, at the helm of community development and holistic wellbeing, are integral to building peaceful global communities through forming compassionate networks of changemakers, leaders and entrepreneurs adopting sustainable livelihood approaches. Following a conference on “Women, Religion and Climate Change, working together to move faster on climate change” which took place at Wilton Park in the UK in September 2023, an official report of findings and recommendations was produced, highlighting the real-life experiences, opportunities, and challenges within this arena. This report will serve as a key case study for this paper, drawing on discussions and focus groups among the diverse multi-lateral participants, influencers, and faith leaders present at this event. This paper will consider emerging approaches related to female leadership including the capability approach, the whole community approach, and the Islamic concept of Maslaha [Maslaha is an Arabic word, which means public interest]. These approaches also promote peaceful and sustainable societies and communities.

Quantyfing the impact of the water security index on socio-economic development in EU27

The issue of environmental security in the context of sustainable development is a highly topical one, being intensively studied by specialists both in terms of its impact on biodiversity and on the protection of non-renewable resources, and in terms of its economic and social impact. The authors aim to quantify the impact of water security on economic and social development based on a new structural equation model and identify changes in the latent variable Water Security Index. (WSI), economic development (ED) and social development (SD) dynamics over the period 2000–2022 for the 27 EU Member States. The methodology is based on the use of structural equation systems and the use of the Independent-Samples Kruskal-Wallis Test to identify the influences of water security measures on economic and social indicators and to assess regional disparities of environmental policy development in relation to economic and social development. The research results will highlight the level of homogeneity of regional water security clusters in Europe and the influence of this approach on economic and social disparities. The results of the study highlight the significant correlation between population density, pollution levels and the costs associated with maintaining water quality. The study shows that high population density and high pollution levels disproportionately increase the financial burden of water quality management. In addition, the analysis highlights the social ramifications of neglecting the sustainability of water sources, particularly in regions experiencing low economic growth. In such scenarios, the negative social impact intensifies, highlighting the importance of sustainable practices. The results allow the formulation of the following public policies: Standardization of the national water quality management framework in line with the European framework; Establishment of organizations to monitor the safety of water sources and the health of the local population; Continuation of innovations in the field of water environment protection; Promotion of social responsibility towards the aquatic environment; Continuation of the process of improving water management governance. The results are useful for economic, environmental and social policy makers to optimise European sustainable development strategies.

Estimating the costs of managed aquifer recharge under uncertainty with examples for town water supply in regional Australia

HighlightsCost distribution curves for well injection and infiltration basin recharge schemes.Probabilistic, time-varying, coupled water balance and net present value modelling.Disaggregated capital and operating expenses and global sensitivity analyses.Examples for increasing regional area town water security in Australia’s Murray Darling Basin.

A CMIP6 multi-model based analysis of potential climate change effects on watershed runoff using SWAT model: A case study of kunhar river basin, Pakistan

The hydrological regimes of watersheds might be drastically altered by climate change, a majority of Pakistan's watersheds are experiencing problems with water quality and quantity as a result precipitation changes and temperature, necessitating evaluation and alterations to management strategies. In this study, the regional water security in northern Pakistan is examined about anthropogenic climate change on runoff in the Kunhar River Basin (KRB), a typical river in northern Pakistan using Soil and Water Assessment tool (SWAT) and flow durarion curve (FDC). Nine general circulation models (GCMs) were successfully utilized following bias correction under two latest IPCC shared socioeconomic pathways (SSPs) emission scenarios. Correlation coefficients (R2), Nash-Sutcliffe efficiency coefficients (NSE), and the Percent Bias (PBIAS) are all above 0.75. The conclusions demonstrate that the SWAT model precisely simulates the runoff process in the KRB on monthly and daily timescales. For the two emission scenarios of SSP2-4.5 and SSP5-8.5, the mean annual precipitation is predicted to rise by 3.08 % and 5.86 %, respectively, compared to the 1980–2015 baseline. The forecasted rise in mean daily high temperatures is expected to range from 2.08 °C to 3.07 °C, while the anticipated increase in mean daily low temperatures is projected to fall within the range of 2.09 °C–3.39 °C, spanning the years 2020–2099. Under the two SSPs scenarios, annual runoff is estimated to increase by 5.47 % and 7.60 % due to climate change during the same period. Future socioeconomic growth will be supported by a sufficient water supply made possible by the rise in runoff. However, because of climate change, there is a greater possibility of flooding because of increases in both rainfall and runoff. As a result, flood control and development plans for KRB must consider the climate change's possible effects. There is a chance that the peak flow will move backwards relative to the baseline.

Real-time mapping of crop canopy temperature using a wireless network of infrared thermometers on a central pivot

Efficient irrigation is essential for sustainable food production and regional water security. Temperature measurements provide information about crop water status, which allows the estimation of water needs and precise irrigation scheduling. This paper proposes a technology for agricultural irrigation management that combines cost-effective implementation with the ability to map crop canopy temperatures using a wireless network of infrared thermometers on a center pivot. The technology integrates Wireless Sensor Networks (WSN) with scalability options, IoT capabilities, and web data availability, enabling precise plant water stress quantification based on canopy temperature and soil water content. It facilitates real-time irrigation prescriptions while the center pivot is in motion, with canopy temperature sensors providing accurate readings of +/- 0.5 °C without additional calibration. Nonlinear Autoregressive Network with Exogenous Inputs (NARX) and Long Short-Term Memory (LSTM) neural network models were trained to predict irrigation prescriptions, achieving Root Mean Squared Error (RMSE < 4.18 mm) and correlation coefficient (r^2 > 0.82). This technology will allow the definition of real-time and site-specific prescriptions for variable-rate irrigation systems using infrared temperature sensors. Future work includes exploring LoRaWAN technologies, implementing a Differential Global Positioning System (DGPS), improving spatial resolution with data fusion algorithms, refining irrigation prescription models, reducing sensor costs and developing models considering soil and crop effects.

Managing the water-agriculture-environment-energy nexus: Trade-offs and synergies in an arid area of Northwest China

Water is a stabilizer for production and life in the arid areas. According to research shared by the Pacific Institute and The Guardian, there were 228 incidents of water conflict globally in 2022. Therefore, comprehensive measures are necessary to achieve regional water security. This objective can be achieved by the application of interdisciplinary and professional approaches through establishing a dynamic equilibrium of the different water consumers, and trade-offs and synergies for water allocation between them. A multi-objective optimization model is proposed for managing the water-agriculture-energy-environment (WAEE) nexus in water-scarce areas. Real and integer-encoded multi-objective evolutionary algorithms (EMCMO) were applied to solving management models. Multiple objectives, such as the maximization of economic benefits from agriculture and hydropower generation, the minimization of ecological water shortages for local plants, and the minimization of environmental risks influenced by land use and food supply, were defined in the model. The model was applied to the Yanqi Basin, an important agriculture and energy producer in Xinjiang province, Northwest China. The results indicated that (1) the four-dimensional Pareto solution set has the advantage of presenting the WAEE nexus, highlighting the trade-offs and synergies between high-value crops, surface water, and groundwater, ecological water demand, hydropower generation and total nitrogen and phosphorus loading (TNP); (2) An excessive increase in the agricultural economy will increase TNP loading and agricultural non-point source pollution; (3) Optimization of WAFE for local ecosystem restoration. Optimization in a wet year, reduced agricultural economic benefits by 0.20%, and agricultural TNP loading by 13.19% while increasing ecological water by 58.33%, and hydropower generation by 3.98%; in a normal year, reduced agricultural economic benefits by 6.62%, agricultural TNP loading by 13.19% while increasing ecological water by 46.43%, and hydropower generation by 0.79%; in a dry year, reduced agricultural economic benefits by 17.19%, agricultural TNP loading by 9.72%, and hydropower generation by 16.18% while increasing ecological water by 42.86%. The trade-offs and synergies of the WAEE nexus also apply to other similar water-scarce areas.

Hydrological dynamics of the Kalisindh and Parbati Rivers: An integrated analysis in the context of the Eastern Rajasthan Canal Project (ERCP)

This study conducts a comprehensive analysis of hydrological patterns in the Kalisindh and Parbati Rivers, highlighting the Eastern Rajasthan Canal Project (ERCP) as pivotal for bolstering regional water security. Employing an array of data sources, this research utilizes Polynomial Regression and neural network forecasting to dissect flow patterns, identifying significant virgin flow peaks in the mid-1980s and early 2000s for the Kalisindh River, and a notable peak in 2006–2007 for the Parbati River. Analysis reveals that the specific discharge rate of the Parbati River is diminishing at twice the rate of the Kalisindh River, with annual decreases of approximately 0.0038 cumecs/km2 for Parbati, compared to 0.0019 cumecs/km2 for Kalisindh. Furthermore, runoff volumes indicate that the Parbati River, specifically at the Khatoli Gauge & Discharge (G&D) site, experiences significantly higher runoff—28,137.912 million cubic meters (MCM)—in contrast to 15,795.094 MCM for the Kalisindh River at the Barod G&D site. The findings accentuate the necessity for science-based water management strategies to effectively combat water scarcity and climate change impacts. The ERCP emerges as a crucial initiative for sustainable management of the Kalisindh and Parbati Rivers in Rajasthan, underscoring its potential to serve as a model for sustainable water and river basin management.

Estimating and Assessing Monthly Water Level Changes of Reservoirs and Lakes in Jiangsu Province Using Sentinel-3 Radar Altimetry Data

Generating accurate monthly estimations of water level fluctuations in reservoirs and lakes is crucial for supporting effective water resource management and protection. The dual-satellite configuration of Sentinel-3 makes it possible to monitor water level changes with great coverage and short time intervals. However, the potential of Sentinel-3’s Synthetic Aperture Radar Altimetry (SRAL) data to enable operational monitoring of water levels across Jiangsu Province on a monthly basis has not yet been fully explored. This study demonstrated and validated the use of Sentinel-3’s SRAL to generate accurate monthly water level estimations needed to inform water management strategies. The monthly water levels of lakes and reservoirs from 2017 to 2021 were produced using Sentinel-3 level-2 land products. Results showed that, compared with in situ data across eight studied lakes, all lakes presented R (Pearson correlation coefficient) values greater than 0.5 and Root Mean Square Error (RMSE) values less than 1 m. Notably, water level estimates for Tai Lake, Gaoyou Lake, and Luoma Lake were particularly accurate, with R above 0.9 and RMSE below 0.5 m. Furthermore, the monthly water level estimates derived from the Sentinel-3 data showed consistent seasonal trends over the multi-year study period. The annual water level of all lakes did not change significantly, except for Shijiu Lake, of which the difference between the highest and lowest water level was up to about 5 m. Our findings confirmed the water level observation ability of Sentinel-3. The accuracy of water level monitoring could be influenced by internal water level differences, terrain features, as well as the area and shape of the lake. Larger lakes with more altimetry sampling points tended to yield higher accuracy estimates of water level fluctuations. These results demonstrate that the frequent, wide-area coverage offered by this satellite platform provides valuable hydrological information, especially across remote regions lacking in situ data. Sentinel-3 has immense potential to support improved water security in data-scarce regions.

Implications of climate change on water quality and sanitation in climate hotspot locations: A case study in Indonesia

Abstract Southeast Asia is vulnerable to climate change with over half of its population already being impacted by drought, flooding, and rise in sea levels recently. This work reviews the current water resource challenges in Indonesia, prone to the rising impacts of climate change. A baseline assessment of Indonesia's water and drinking water resources related to its original sources is presented. In response to a growing concern over chronic challenges that undermine water supply nationwide, this study analyses drinking water safety supervision. To accomplish this, a literature survey (100 studies published during the 2000–2023 period) was performed to identify regional groundwater resources sustainability and water security issues. Among the main findings of this study, only 10% of rainfall infiltrates to the groundwater, while 70% of its rivers are heavily polluted by domestic waste. During the study period, water availability decreased to 1,200 m3/year in 2020, with only 35% of the resources being economically feasible for reuse. The water supply deficit in Indonesia was estimated to be 5.5 hm3/year with roughly 67% of the population's water demand satisfied in 2021. Although this deficit might be fulfilled with private vendors, water supply/demand forecasts in 2030 suggest that the gap could not be closed by increasing water supply.