Indicators to complement global monitoring of safely managed on-site sanitation to understand health risks.

Halfway through the Sustainable Development Goal (SDG) period, there has been little research on the criteria for monitoring safely managed sanitation under SDG target 6.2. For reporting against SDGs, global indicators are necessarily limited and exclude many safety aspects from a public health perspective. Primary survey data from 31,784 households in seven countries in Asia and Africa were analysed, comparing estimates of safely managed on-site sanitation based on global indicators with five complementary indicators of safety: animal access to excreta, groundwater contamination, overdue emptying, entering containments to empty and inadequate protection during emptying. Application of additional criteria reduced the population with safely managed sanitation by 0.4-35% for specific indicators, with the largest impact due to the risk of groundwater contamination, animal access, and containments overdue for emptying. Combining these indicators across the service chain, excluding transport and treatment, found almost three-quarters of on-site systems currently assessed as safely managed with global indicators were considered unsafe based on complementary indicators. A more comprehensive assessment of safety of on-site sanitation can be achieved through these indicators, which could be integrated into national monitoring systems and used to inform sanitation investments that address local health-related risks.

Security assessment and diagnosis for industrial water resources using TODIMSort considering Best-Worst Method with double hierarchy hesitant fuzzy linguistic term set.

Motivated by the driving force to address global water scarcity, industrial water resources, as the second largest consumption of water resources, its security assessment plays a crucial role in improving the current situation. Hence, this paper proposes a novel methodology to conduct the industrial water resources security (IWRS) assessment. Firstly, a more targeted assessment system based on the framework of the Pressure-State-Response (P-S-R) on IWRS is established. Then, enhanced with a double hierarchy hesitant fuzzy linguistic term set (DHHFLTS), the Best-Worst Method (BWM) now determines subjective weights through DHHFLTS-BWM (DF-BWM). By introducing the Criteria Importance Through Intercriteria Correlation (CRITIC) method, which considers the indicator inteactions, objective weights are obtained to modify the subjective weights. Furthermore, the global dominance of all alternatives is calculated by a TODIMSort method and grading them. Moreover, 16 cities in Anhui Province are taken as examples to assess IWRS in the decade from 2011 to 2020. Comparative analysis with original BWM, time series analysis, sensitivity analysis on loss attenuation coefficient, coupling and coordination analysis and obstacle analysis on all indicators are conducted to verify the rationality, effectiveness, and stability of the proposed assessment methodology. Simultaneously, explore the existing issues within IWRS. It can be seen from the results that the performance of Lu'an and Huainan cities is relatively better, while Ma'anshan city shows relatively poorer performance. In addition, per capita water resources and wastewater treatment facilities have a significant impact on the IWRS. Finally, some management suggestions are proposed to enhance the scientific and effective management of industrial water resources and ensure their sustainable utilization.

Global Water Challenges in Sub-Saharan Africa and how to strengthen science-policy dialogues on transboundary governance and cooperation.

The United Nations Water Conference 2023 highlighted the need for concrete actions to boost integrated water resources management for achieving the Sustainable Development Goals and called for strategies to enhance cooperation among stakeholders. Technical cooperation between countries and institutions in transboundary systems, e.g., on environmental data collection, is an effective way to promote international diplomacy and prevent disputes between riparian states. Still, establishing collaborations to inform bilateral dialogues on the identification of environmental challenges, their causes, and development priorities may be a difficult task in itself. This is particularly true in the African context because of limited resources and lack of data. In this paper, we analyse the case of nine transboundary river basins in Sub-Saharan Africa to identify which water-management challenges are perceived as most important by the different riparian countries from a policy and scientific perspective. Our insights are based on the most up-to-date scientific papers, open access reports and technical literature, river basin authority's strategy papers, projects' summary reports, and national policy documents. We also complement these sources with the pieces of information we gained through collaborations with regional and local experts, and management bodies (such as river basin authorities). We highlight the current water-related conflicts and the gap between the priorities identified by the scientific community and different riparian countries on how to tackle hydro-climatic change and improve food and energy security, human and environmental health. Based on our experience, we discuss some keys to building trust among stakeholders, strengthening cooperation, and identifying shared water-governance measures in transboundary river basins. They are: (i) connect science and policy to provide sound knowledge for the right questions, (ii) value local knowledge and exploit the complementarity of different perspectives, (iii) consider multiple spatial scales and multi-level stakeholders to leave no one behind, (iv) promote a culture which values trade-offs and handles complexity, and (v) co-create data and knowledge to facilitate stakeholder dialogue from problem definition to intervention identification.

Modeling Al-Qaraqoul canal before and after rehabilitation using HEC-RAS.

The Egyptian Ministry of Water Resources and Irrigation launched in 2020 the national project to rehabilitate the canals network to rationalize the use of water resources to face the scarcity problems. The aim of study is to evaluate the impact of canal rehabilitation on the performance of irrigation water delivered laterally to Mesqa's and longitudinally to the end of canal. Qaraqoul Canal et al.-Mallah Area, Alexandria, Egypt, was modeled using Hydrologic Engineering Center's-River Analysis System (HEC-RAS) to simulate water levels in the canal before and after rehabilitation using four discharge scenarios: 1.82, 3.7, 2.2, 7.87 m3/s. The calibration before rehabilitation shows that HEC-RAS simulated water levels corresponding to a discharge of 2.2 m3/s were in a good agreement with the actual field measured water levels. HEC-RAS results demonstrated that rehabilitation hydraulically improved the efficiency and performance of water conveyed by the canal. On the other hand, second scenario can be considered as suitable to keep water to reach the canal downstream with minimum suitable discharge, providing the need of two emergency pumps at last two branch canals called Mesqa's. An ideal cross-section is also simulated using HEC-RAS which produced an efficient alternative with 40% less cost than the constructed alternative.

Historical reconstruction of glacier mass balance and its contribution to water resources in the Sawir Mountains from 2000 to 2020.

Glacial changes are crucial to regional water resources and ecosystems in the Sawir Mountains. However, glacial changes, including the mass balance and glacial meltwater of the Sawir Mountains, have sparsely been reported. Three model calibration strategies were constructed including a regression model based on albedo and in-situ mass balance of Muz Taw Glacier (A-Ms), regression model based on albedo and geodetic mass balance of valley, cirque, and hanging glaciers (A-Mr), and degree-day model (DDM) to obtain a reliable glacier mass balance in the Sawir Mountains and provide the latest understanding in the contribution of glacial meltwater runoff to regional water resources. The results indicated that the glacial albedo reduction was significant from 2000 to 2020 for the entire Sawir Mountains, with a rate of 0.015 (10a)-1, and the spatial pattern was higher in the east compared to the west. Second, the three strategies all indicated that the glacier mass balance has been continuously negative during the past 20 periods, and the average annual glacier mass balance was -1.01 m w.e. Third, the average annual glacial meltwater runoff in the Sawir Mountains from 2000 to 2020 was 22 × 106 m3, and its contribution to streamflow was 25.81 % from 2000 to 2018. The glacier contribution rates in the Ulkun- Ulastu, Lhaster, and Kendall River basins were 31.37 %, 22.51 %, and 19.27 %, respectively.

Principles and research progress of physical prevention and control technologies for algae in eutrophic water.

The abnormal reproduction of algae in water worldwide is prominent in the context of human interference and global climate change. This study first thoroughly analyzed the effects of physical factors, such as light, temperature, hydrodynamics, and operational strategies, on algal growth and their mechanisms. Physical control techniques are safe and have great potential for preventing abnormal algal blooms in the absence of chemical reagents. The focus was on the principles and possible engineering applications of physical shading, ultrasound, micro-current, and ultraviolet (UV) technologies, in controlling abnormal algal reproduction. Physical shading can inhibit or weaken photosynthesis in algae, thereby inhibiting their growth. Ultrasound mainly affects the physiological and biochemical activities of cells by destroying the cell walls, air cells, and active enzymes. Micro-currents destroy the algal cell structure through direct and indirect oxidation, leading to algal cell death. UV irradiation can damage DNA, causing organisms to be unable to reproduce or algal cells to die directly. This article comprehensively summarizes and analyzes the advantages of physical prevention and control technologies for the abnormal reproduction of algae, providing a scientific basis for future research. In the future, attempts will be made toward appropriately and comprehensively utilizing various physical technologies to control algal blooms. The establishment of an intelligent, comprehensive physical prevention and control system to achieve environmentally friendly, economical, and effective physical prevention and control of algae, such as the South-to-North Water Diversion Project in China, is of great importance for specific waters.

Equal allocation, demand priority or negotiated allocation? How to allocate water resources in the Tigris and Euphrates River Basin efficiently.

The Tigris and Euphrates River Basin is an important water supply, but it suffers from water scarcity. It is necessary to carry out reasonable allocation of water resources in this region. Since water resources issues in this region are of multinational interest, international cooperative distribution efforts are needed. Common water resources allocation modes include equal allocation, demand priority or negotiation allocation. In order to derive the applicable range of various water resources allocation modes, this article constructs three differential game models and compares and analyzes the equilibrium results obtained by the models. Finally, the study shows that when the cost of developing water resources is small and the revenue obtained from developing water resources is large, the water-scarce region can obtain the maximum benefit by adopting the demand priority mode. Otherwise, the water-scarce region can obtain the maximum benefit by adopting the negotiation allocation mode. This study can inform the allocation, strategic interaction and cooperation of dynamic water resources in the two river basins.

Using stable isotopes to inform water resource management in forested and agricultural ecosystems.

Present and future climatic trends are expected to markedly alter water fluxes and stores in the hydrologic cycle. In addition, water demand continues to grow due to increased human use and a growing population. Sustainably managing water resources requires a thorough understanding of water storage and flow in natural, agricultural, and urban ecosystems. Measurements of stable isotopes of water (hydrogen and oxygen) in the water cycle (atmosphere, soils, plants, surface water, and groundwater) can provide information on the transport pathways, sourcing, dynamics, ages, and storage pools of water that is difficult to obtain with other techniques. However, the potential of these techniques for practical questions has not been fully exploited yet. Here, we outline the benefits and limitations of potential applications of stable isotope methods useful to water managers, farmers, and other stakeholders. We also describe several case studies demonstrating how stable isotopes of water can support water management decision-making. Finally, we propose a workflow that guides users through a sequence of decisions required to apply stable isotope methods to examples of water management issues. We call for ongoing dialogue and a stronger connection between water management stakeholders and water stable isotope practitioners to identify the most pressing issues and develop best-practice guidelines to apply these techniques.

Effects of damage initiation points of depth-damage function on flood risk assessment.

The flood depth in a structure is a key factor in flood loss models, influencing the estimation of building and contents losses, as well as overall flood risk. Recent studies have emphasized the importance of determining the damage initiation point (DIP) of depth-damage functions, where the flood damage is assumed to initiate with respect to the first-floor height of the building. Here we investigate the effects of DIP selection on the flood risk assessment of buildings located in Special Flood Hazard Areas. We characterize flood using the Gumbel extreme value distribution's location (µ) and scale (α) parameters. Results reveal that average annual flood loss (AAL) values do not depend on µ, but instead follow an exponential decay pattern with α when damage initiates below the first-floor height of a building (i.e., negative DIP). A linear increasing pattern of the AAL with α is achieved by changing the DIP to the first-floor height (i.e., DIP = 0). The study also demonstrates that negative DIPs have larger associated AAL, thus contributing substantially to the overall AAL, compared to positive DIPs. The study underscores the significance of proper DIP selection in flood risk assessment.

Establishing a river health evaluation index system for seven rivers in Jiamusi City of China.

The Jiamusi section of the Songhua River is one of the first 17 model river construction sections in China. The implementation of river health assessments can determine the health dynamics of rivers and test the management's effectiveness. Targeting seven rivers, this study conducted river zoning and monitoring point deployment to conduct sufficient field research and monitoring. The authors selected hydrological and water resources, physical structure, water quality, aquatic life, social service functions, and management as guideline layers and 15 indicator layers. Subsequently, the authors established an evaluation index system to evaluate and analyze the ecological status and social service status of each river. The results showed that the Yindamu, Alingda, and Gejie rivers scored well as healthy rivers, with health evaluation scores of 78.98, 76.06, and 75.83, respectively. The Wangsanwu, Lujiagang, and Lingdangmai rivers are generally sub-healthy rivers with scores of 71.55, 67.97, and 60.7, respectively. The Yinggetu River has a score of 54.52 and is therefore assessed as unhealthy. Based on the scientific evaluation index method, this study analyses the current river health state in Jiamusi City to provide the basis for the evaluation of the river chief's work and future river management.

Pollution, spatial distribution, and health risks assessment of nutrient concentration in surface water resources of Maroon-Jarahi Basin in southwestern Iran.

Nowadays, the introduction of nutrients caused by human activities is considered an environmental issue and a significant problem in river basins and coastal ecosystems. In this study, the concentration of nutrients ( NO 3 - and PO 4 3 - ) in the surface water sources of the Maroon-Jarahi watershed in the southwest of Iran was determined, and the pollution status and health risk assessment were done. The average concentration of nitrate and phosphate in Ludab, Maroon, Zard, Allah, Jarahi rivers, and Shadegan wetland were obtained at 2.25-0.59, 4.59-1.84, 4.07-2.02, 5.40-2.81, 11.51-4.67, 21.63 and 6.20 (mg/l), respectively. A comparison of the results with the World Health Organization (WHO) limit showed that nitrate was lower than in all stations, but phosphate was higher than the limit in some stations of the Maroon, Allah, Jarahi rivers, and Shadegan wetland. Calculation of linear regression analysis showed significant positive relationships between nitrate and phosphate in all surface water sources (except Ludab) and based on the N/P ratio, nitrogen was estimated as the limiting factor in phytoplankton growth (N/P < 16). The evaluation of the status of the Nutrient pollution index (NPI) was observed as: Shadegan > Jarahi > Allah > Maroon > Zard > Ludab that the Jarahi River and Shadegan wetland were in the medium pollution class (1 < NPI ≤ 3) and other waterbodies were in the non-polluted to low pollution state (NPI < 1). Calculation of the chronic daily intake (CDI) showed that water body nutrients cause more non-carcinogenic health risks through the oral route than dermal exposure, and according to HI, children's health is more at risk than adults. Findings showed that surface water resources especially downstream of the Maroon-Jarahi watershed are at eutrophication risk, and to control the nearby human activities and as a result increase the nutrients in these water resources, measures should be taken.

The selection of paired watersheds affects the assessment of wildfire hydrological impacts.

Wildfires strongly alter hydrological processes and surface and groundwater quality in forested environments. The paired-watershed method, consisting of comparing a burnt (altered) watershed with an unburnt (control) watershed, is commonly adopted in studies addressing the hydrological effects of wildfires. This approach requires a calibration period to assess the pre-perturbation differences and relationships between the control and the altered watershed. Unfortunately, in many studies, the calibration phase is lacking due to the unpredictability of wildfires and the large number of processes that should be investigated. So far, no information is available on the possible bias induced by the lack of the calibration period in the paired-watershed method when assessing the hydrological impacts of wildfires. Through a literature review, the consequences of the lack of calibration on the assessment of wildfire hydrological changes were evaluated, along with the most used watershed pairing strategies. The literature analysis showed that if calibration is lacking, misestimation of wildfire impacts is likely, particularly when addressing low-severity or long-term wildfire effects. The Euclidean distance based on physical descriptors (geology, morphology, vegetation) was proposed as a metric of watersheds similarity and tested in mountain watersheds in Central Italy. The Euclidean distance proved to be an effective metric for selecting the most similar watershed pairs. This work raises awareness of biases exerted by lacking calibration in paired-watershed studies and proposes a rigorous and objective methodology for future studies on the hydrological effects of wildfires.

The Source-to-Sea Landscape: A hybrid integrative territory management approach.

Whether fresh or salty, water is a unique resource, a continuum interlinked by the hydrological cycle. It forms a complex system connected to the landscape. When the landscape is altered, water flows and their benefits are impacted. Degraded land compromises water resources. The governance and management of landscape and water resources are handled in a fragmented manner and in separate contexts. The Source-to-Sea approach offers an integrative vision based on systems thinking that focuses its concerns on the interaction among parts, flows, and processes. It proposes a framework for the governance and management of freshwater and marine water but does not bring the landscape into the context of the approach. This research used an analytical-deductive method to explore the interactions and connections between the Source-to-sea approach, landscape concepts and approaches, and the guidelines of the European Landscape Convention. The main objective was to identify and assess the feasibility of integrating these elements. The integration resulted in a governance and management approach termed the S2S Landscape approach. It is grounded in systems thinking, practical learning, active participation, and adaptive governance and management, providing an integrated vision between landscape and water. The approach includes four essential steps (Comprehension, Involvement, Planning, and Execution and Monitoring) that address the complex connections that freshwater and marine water maintain in the landscape, considering physical, biological, socio-environmental, and economic aspects across all segments, from the land to the open sea. This S2S Landscape approach may be the path to address the challenges of governance and sustainable management of resources in an interconnected and constantly changing world.

Quantifying the mutual effects of water trading and systematic water saving in a water-scarce watershed of China.

In this study, a conjunctive water management model based on interval stochastic bi-level programming method (CM-ISBP) is proposed for planning water trading program as well as quantifying mutual effects of water trading and systematic water saving. CM-ISBP incorporates water resources assessment with soil and water assessment tool (SWAT), systematic water-saving simulation combined with water trading, and interval stochastic bi-level programming (ISBP) within a general framework. Systematic water saving involves irrigation water-saving technologies (sprinkler irrigation, micro-irrigation, low-pressure pipe irrigation), enterprise water-saving potential and water-saving subsidy. The CM-ISBP is applied to a real case of a water-scarce watershed (i.e. Dagu River watershed, China). Mutual effects of water trading and water-saving activities are simulated with model establishment and quantified through mechanism analysis. The fate of saved water under the systematic water saving is also revealed. The coexistence of the two systems would increase system benefits by [11.89, 12.19]%, and increase the water use efficiency by [40.04, 40.46]%. Thus mechanism that couples water trading and water saving is optimal and recommended according to system performance.

Stacked hybridization to enhance the performance of artificial neural networks (ANN) for prediction of water quality index in the Bagh river basin, India.

Water quality assessment is paramount for environmental monitoring and resource management, particularly in regions experiencing rapid urbanization and industrialization. This study introduces Artificial Neural Networks (ANN) and its hybrid machine learning models, namely ANN-RF (Random Forest), ANN-SVM (Support Vector Machine), ANN-RSS (Random Subspace), ANN-M5P (M5 Pruned), and ANN-AR (Additive Regression) for water quality assessment in the rapidly urbanizing and industrializing Bagh River Basin, India. The Relief algorithm was employed to select the most influential water quality input parameters, including Nitrate (NO3-), Magnesium (Mg2+), Sulphate (SO42-), Calcium (Ca2+), and Potassium (K+). The comparative analysis of developed ANN and its hybrid models was carried out using statistical indicators (i.e., Nash-Sutcliffe Efficiency (NSE), Pearson Correlation Coefficient (PCC), Coefficient of Determination (R2), Mean Absolute Error (MAE), Root Mean Square Error (RMSE), Relative Root Square Error (RRSE), Relative Absolute Error (RAE), and Mean Bias Error (MBE)) and graphical representations (i.e., Taylor diagram). Results indicate that the integration of support vector machine (SVM) with ANN significantly improves performance, yielding impressive statistical indicators: NSE (0.879), R2 (0.904), MAE (22.349), and MBE (12.548). The methodology outlined in this study can serve as a template for enhancing the predictive capabilities of ANN models in various other environmental and ecological applications, contributing to sustainable development and safeguarding natural resources.

Ecological risk of metals in Andean water resources: A framework for early environmental assessment of mining projects in Peru.

Metallic contaminants in Andean water resources influenced by mining activities poses risks to aquatic ecosystems and a challenge to regulatory agencies responsible for environmental compliance. In this study, the Ecological Risk Assessment (ERA) framework was adapted to assess dissolved heavy metal concentrations at 283 surface water monitoring stations near to six mining projects during the dry and wet seasons. Reports from OEFA-Peru on Early Environmental Assessment (EEA) were used to apply various criteria and non-parametric statistical tests. They included ecological, ecotoxicological, chemical, and regulatory factors. The main goal of this research was to identify, analyze, characterize, and compare the risks present at different trophic levels. These levels were categorized as T1 (Microalgae), T2 (Zooplankton and Benthic invertebrates), and T3 (Fish). Individual risk (IR) was estimated using the quotient model, while total risk (TR) was assessed using the additive probability rule. Rainbow trout (Oncorhynchus mykiss), representing trophic level T3, showed the highest sensitivity to Fe and Cu. Statistical tests ranked the IR as Fe > Cu > Zn > Mn > Pb (p < 0.01). The TR was more prevalent during the wet season compared to the dry season (p < 0.01). Notably, around 50 % of the monitoring stations (n = 142) were classified as high risk, and 9 % (n = 13) showed extremely high-risk values for Cu and Fe. The adapted ERA framework demonstrated great effectiveness in identifying critical points of metal contamination in high Andean aquatic ecosystems under mining influence. However, specialized studies are suggested that allow the sources of pollution to be associated with specific regulatory actions.

Transforming the Water-Energy Nexus in Gaza: A Systems Approach.

The acute water and electricity shortages in Gaza necessitate comprehensive solutions that recognize the interconnected nature of these vital resources. This article presents pragmatic solutions to align supply with fundamental needs in both domains, offering viable pathways for achieving strategic water-energy security in Gaza. Baseline data reveals a deficit in the current water supply, falling below the international minimum of 100 L per capita per day, while the reported 137-189 MW per day electricity supply significantly lags behind the estimated 390 MW per day peak demand. To meet projected 2024 residential, commercial, and industrial demands, this study proposes actionable measures including expanding wastewater treatment to enable over 150 MCM per year tertiary effluents for agricultural reuse and adopting energy-efficient forward osmosis-reverse osmosis and osmotically assisted reverse osmosis desalination methods to increase potable water supply to 150 MCM per year. Electricity supply strategies include scaling renewable capacity towards 110 MW per day, exploring regional cooperation to unlock over 360 MW of power per day, and potentially recovering up to 60 MW per day through system efficiencies. These recommendations aim to prevent exacerbated scarcity and alleviate hardships in Gaza.