Global Water Security Research Articles

Sustainable development goal 6: Global Water Security

Sustainable development goal 6: Global Water Security

Delivering global water security: Embedding water justice as a response to increased irrigation efficiency

AbstractIncreasingly, irrigation infrastructure upgrades have been regarded in global policy as a solution for both water scarcity and low agricultural productivity. However, these technical “fixes” may ultimately prove to be dangerous shortcuts that do little to address the concerns of irrigators, Indigenous People, environmental groups, and local communities about water scarcity, access, security, and sustainability. In the absence of transparent and rigorous governance safeguards, irrigation efficiency upgrades can result in higher water consumption, demand, and ultimately, increased water scarcity. Upgraded irrigation systems also tend to capture return flows and redistribute them to “high value” consumptive water uses, potentially displacing other users and uses, including Indigenous Peoples. In this article, we critique current approaches to governing irrigation efficiency, using a water justice lens to identify four key insights and their implications for governance. We propose new governance pathways and options that take into consideration hydrological realities and the full range of water demands and needs.This article is categorized under: Human Water > Water Governance Water and Life > Conservation, Management, and Awareness Human Water > Water as Imagined and Represented

Observational Evidence for Multivariate Drought Hazard Amplifications Across Disparate Climate Regimes

AbstractDrought poses significant challenges to global water security in a warming world. A global‐scale synthesis of the multivariate drought risk considering interdependencies between drought attributes across disparate climate regimes is still lacking. Leveraging precipitation and streamflow observations of 270 large catchments over the globe, we show that multivariate drought hazard amplifies significantly (at ∼65–76% of catchments) considering dependence between drought duration and severity. A signifying nature of this amplification (A) is the power‐law scaling with dependence metric ( where τ and λ are Kendall's correlation and the scaling exponent), revealing current approaches considering drought attributes as independent or linearly dependent will severely underestimate likelihood of extreme droughts. Furthermore, we find disparate responses in the multivariate imprints of meteorological to hydrological droughts across climate types, with strengths varying from large to modest in Tropics and Mid‐latitudes, which indicates weaker overlap between rain‐deficit and streamflow droughts. In contrast, a strong overlap in multivariate hazards of rain‐deficit and streamflow droughts is apparent across transitional Subtropics. Our study highlights the relevance of accounting for multivariate aspects of drought hazards to inform adaptation to water scarcity in a changing climate.

Water Security: Why We Need Global Solutions

Abstract The article introduces some of the general challenges of global water security (in the context of the availability of good quality water) and highlights the likely global impact of climate change, increasing pollution and population growth on water resources, including flooding and droughts, as outlined in recent studies. The nexus between water, food and energy is introduced, along with the concept of virtual water, and the desirability for society, industry and governments to consider water security in a global context. Cotton production and trading is considered as an example and how clothes purchased in a non-cotton producing country can have an adverse impact on the water quality and pollution levels in river basins in cotton producing countries and in any other countries further downstream in the river basin. The role and engagement of engineers is highlighted and how engineers can contribute significantly to addressing the challenges of Sustainable Development Goal 6, i.e., ‘ensure availability and sustainable management of water and sanitation for all’.

Empirical Setting of the Water Stressed Baseline Increases the Uncertainty of the Crop Water Stress Index in a Humid Temperate Climate in Different Water Regimes

Water productivity of rice is imperative for global water security. Currently, water saving management techniques have been proposed and applied to rice systems. The crop water stress index (CWSI) is a major index for evaluating crop water use. The utility of the CWSI in rice in a humid temperate climate has been given little attention. Previous studies have focused on upland crops and readily available constant reference baselines, primarily the water stressed baseline (WSB), which does not inherently reflect transpiration flux. This study examined the performance of the estimated non-water stressed baseline (NWSB) and WSB for rice in a humid climate and the CWSI sensitivity under variable reference baseline scenarios in a 2-year pot trial under phytotron and field environment conditions with two rice genotypes (IRAT109 and Takanari) in a flooded (FL) and aerobic (AR) water regime. We observed that the dynamics of CWSI is dependent not only on the water regimes but could be strongly influenced by genotype sensitivity to vapor pressure deficit (VPD). A higher slope (pooled data) in the field environment (−5.68 °C kPa−1) compared to the phytotron (−3.04 °C kPa−1) reflected transpiration water loss sensitivity to VPD thresholds. Further studies with diverse rice germplasms to explore generalizability to field conditions and reformulation of reference baselines considering the VPD threshold sensitivity could prove to be significant.

From the President: We Do Have a Role to Play in Addressing Global Challenges

As we cautiously emerge from the worst of the COVID-19 pandemic, we find ourselves facing a “new” world challenged with difficult problems on a global scale, including energy and water security, clean environment, climate change and global warming, and even access to and equity in health care. Fortunately, as ECS members our collective skill sets and expertise in many of these areas not only uniquely position us to make impactful contributions, but also task us with the responsibility to address the grand challenges of our century toward chartering a sustainable future for the next generations.

Determination of key parameters in water quality monitoring of the most sediment-laden Yellow River based on water quality index

Water quality management of sediment-laden rivers is a challenging issue for global water security because sediment is a major carrier for the migration and transformation of biogenic elements and pollutants in river systems. A water quality index (WQI) based on multiple parameters is widely used when making water quality assessments. To reduce the analytical costs and time required for multi-parameter measurements, many minimum WQI (WQImin) models that rely on fewer key parameters are now being developed for river systems. However, no systematic study of WQImin has been conducted yet in sediment-laden rivers, such as China’s Yellow River which has the highest sediment concentration worldwide. This study assessed the spatiotemporal variation in water quality of the Yellow River’s main channel in the spring and autumn of 2019. The WQI was calculated based on 15 water parameters determined at 44 sampling points from 26 river sections and six reservoirs. A heavy metal evaluation index (HEI) was used to gauge the pollution level of eight heavy metals. Despite no distinct seasonal variation, the WQI values decreased from the Yellow River’s source region to its estuary, and higher values were observed in most reservoirs than in adjacent natural river sections. Values for WQI (>50) were mainly classified as being at “good” and “moderate” water quality levels, while the HEI values (<10) indicated a low pollution level. Four weighted and four non-weighted WQImin models were developed using stepwise regression. A model consisting of six parameters—total suspended solids, ammonia-nitrogen, permanganate index, electrical conductivity, dissolved oxygen, and nitrate-nitrogen—had the best modeling performance. Both the prediction accuracy and goodness-of-fit of the WQImin model were improved after adding parameter weights. Our study provides support data for water resource management in the Yellow River Basin, and contributes to the development of a robust WQImin in sediment-laden rivers.

The top 100 global water questions: Results of a scoping exercise

<h2>Summary</h2> Global water security presents a complex problem for human societies and will become more acute as the impacts of climate change escalate. Water security connects the practical water and sanitation challenges of households to the dynamics of global hydroclimates and ecosystems in the Anthropocene. To ensure the successful deployment of attention and resources, it is necessary to identify the most pressing questions for water research. Here, we present the results of a scoping exercise conducted across the global water sector. More than 400 respondents submitted an excess of 4,000 potential questions. Drawing on expert analysis, we highlight 100 indicative research questions across six thematic domains: water and sanitation for human settlements; water and sanitation safety risk management; water security and scarcity; hydroclimate-ecosystem-Anthropocene dynamics; multi-level governance; and knowledge production. These questions offer an interdisciplinary and multi-scalar framework for guiding the nature and space of water research for the coming decades.

Estimating the cost of achieving basic water, sanitation, hygiene, and waste management services in public health-care facilities in the 46 UN designated least-developed countries: a modelling study

SummaryBackgroundAn alarming number of public health-care facilities in low-income and middle-income countries lack basic water, sanitation, hygiene (WASH), and waste management services. This study estimates the costs of achieving full coverage of basic WASH and waste services in existing public health facilities in the 46 UN designated least-developed countries (LDCs).MethodsIn this modelling study, in-need facilities were quantified by combining published counts of public facilities with estimated basic WASH and waste service coverage. Country-specific per-facility capital and recurrent costs to deliver basic services were collected via survey of country WASH experts and officials between Sept 24 and Dec 24, 2020. Baseline cost estimates were modelled and discounted by 5% per year. Key assumptions were adjusted to produce lower and upper estimates, including adjusting the discount rate to 8% and 3% per year, respectively.FindingsAn estimated US$6·5 billion to $9·6 billion from 2021 to 2030 is needed to achieve full coverage of basic WASH and waste services in public health facilities in LDCs. Capital costs are $2·9 billion to $4·8 billion and recurrent costs are $3·6 billion to $4·8 billion over this time period. A mean of $0·24–0·40 per capita in capital investment is needed each year, and annual operations and maintenance costs are expected to increase from $0·10 in 2021 to $0·39–0·60 in 2030. Waste management accounts for the greatest share of costs, requiring $3·7 billion (46·6% of the total) in the baseline estimates, followed by $1·8 billion (23·1%) for sanitation, $1·5 billion (19·5%) for water, and $845 million (10·7%) for hygiene. Needs are greatest for non-hospital facilities ($7·4 billion [94%] of $7·9 billion) and for facilities in rural areas ($5·3 billion [68%]).InterpretationInvestment will need to increase to reach full coverage of basic WASH and waste services in public health facilities. Financial needs are modest compared with current overall health and WASH spending, and better service coverage will yield substantial health benefits. To sustain services and prevent degradation and early replacement, countries will need to routinely budget for operations and maintenance of WASH and waste management assets.FundingWHO (including underlying grants from the governments of Japan, the Netherlands, and the UK), World Bank (including an underlying grant from the Global Water Security and Sanitation Partnership), and UNICEF.TranslationsFor the Arabic, French and Portuguese translations of the abstract see Supplementary Materials section.

Closing of the yield gap can be achieved without groundwater extraction in Chinese wheat production

Groundwater depletion threatens global water and food security. Despite local successes in reducing groundwater extraction, the potential for transitioning currently irrigated systems to rainfed systems to address both production and groundwater use problems remains poorly understood at the national level. Here, we consider wheat production in China, which strongly benefits from groundwater irrigation, to assess the potential for achieving zero groundwater extraction, while maintaining current production. Using data from 1273 counties, we assessed the area-weighted potential yield and water productivity, and established the attainable values for each county using the top 10% of producers in the county. When data were aggregated at the national level, wheat yield and water productivity improved by 34% and 26% respectively, by closing gaps between the mean and attainable values. We next mapped the county-by-county acreage allocation and calculated the attainable production capacity. The results revealed that China could maintain wheat production without groundwater extraction by reducing the yield gap. This work provides essential insights and detailed spatiotemporal information for policymakers working to achieve groundwater and food sustainability.

GLOBAL WATER SCARCITY DUE TO CLIMATE CHANGE AND ITS CONSERVATION STRATEGIES WITH SPECIAL REFERENCE TO INDIA : A REVIEW

The strategic importance of fresh water for global water and food security will probably intensify under climate change which worsen the situation as it leads to increased frequency and intensity of climatic extremes such as flood, drought, cyclone, heat/ cold waves, alteration in water cycle, water resources depletion, increased variability of precipitation, salt water intrusion in aquifers, increasing irrigation demand, decreasing soil moisture and rapid evaporation of surface water and many more. This review provides an insight about climate change and its impact on quantity and quality of water, water scarcity on a global scale with emphasis on Indian water resources, its availability and conservation strategies to mitigate water scarcity. Global warming resulting in climate change is expected to account for about 20% of the global increase in water scarcity. Global water consumption has increased six fold in last century and in coming decades is expected to grow rapidly. By 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity, and two-thirds of the world's population could be living under water stressed conditions. African continent is the worst affected by the scarcity of water. The gross per capita water availability in India will decline from about 1820 m3 per year in 2001 to as low as about 1140 m3 per year in 2050. It is estimated that the country would need 1180 billion cubic meters (BCM) of water annually by 2050. So, there is an urgent need of sustainable utilization of water resources, formulation of climate adaption strategies, making the people and government aware about shrinking water resources as well as taking urgent action for conservation and harvesting of water at local, national and global scale.

Sustainable Groundwater Management, Addressing Depletion Through Advanced Technology and Policy

Groundwater depletion poses a critical threat to global water security, agriculture, and ecosystems, with unsustainable extraction rates contributing to declining water tables, land subsidence, and environmental degradation. This article explores the integration of advanced technology and policy frameworks as a sustainable solution for managing groundwater resources. Technologies such as remote sensing, artificial intelligence (AI), machine learning, and smart irrigation systems are playing pivotal roles in monitoring and optimizing groundwater usage. Additionally, blockchain technology offers transparency in water rights management, ensuring accountability in resource allocation, technological advancements alone are insufficient to address the issue. Effective policy frameworks, including regulatory limits, groundwater pricing, and community-based management, are necessary to enforce responsible water extraction and promote equitable access. International cooperation is crucial, particularly in regions where transboundary aquifers exist. This paper advocates for a collaborative approach that combines cutting-edge technology with robust governance to ensure sustainable groundwater management. Data-driven decision-making, public education, and the integration of technology into governance structures are essential for long-term groundwater conservation. By aligning these strategies, societies can mitigate the negative impacts of groundwater depletion and protect this critical resource for future generations.

Redox-Active Magnetic Composites for Anionic Contaminant Removal from Water.

Global water security is jeopardized by the presence of anthropogenic contaminants, which can persist resiliently in the environment and adversely affect human health. Surface adsorption of polluting species is an effective technique for water purification. In this work, redox-active magnetic compounds were designed for the targeted removal of inorganic and organic anions in water via polymeric redox-active vinylferrocene (VFc) and pyrrole (Py) moieties. An Fe3O4@SiO2@PPy@P(VFc-co-HEMA) composite was prepared in a four-step process, with the outermost layer possessing heightened hydrophilicity as a result of the optimized incorporation of 2-hydroxyethylmethacrylate (HEMA) monomers into the backbone of the ferrocene macromolecule. The synthesized materials are able to separate carcinogenic hexavalent chromium oxyanions and other charged micropollutants, and exhibit a 2-fold or greater enhancement in adsorption uptake once the redox-active ferrocene groups are oxidized to ferrocenium cations, with capacities of 23, 49, 66, and 95 mg/g VFc for maleic acid, 2-(6-methoxy-2-naphthyl)propionic acid (Naproxen), (2,4-dichlorophenoxy)acetic acid (2,4-D), and (2-dodecylbenzene)sulfonic acid (DBS), respectively, and a > 99% extractability of chromium in the 1 ppm range. The application of redox-active components to a magnetic particulate scaffold improves maneuverability and phase contact, giving rise to new potential aqueous separation process frameworks for water or product purification.

Cationic covalent organic framework membranes for efficient dye/salt separation

Wastewater containing organic dyes and high content of salts has posed a serious challenge on global water security. Herein, a cationic nanoporous covalent organic framework (COF) membrane is constructed via a facile interfacial growth strategy. The prepared membranes show excellent dye/salt separation performance with a pure water flux above 24 L m−2 h−1 bar−1. The rejection rate of methylene blue of positive charges is above 99%, while the rejection rates of NaCl, Na2SO4, MgSO4 are only 3.2%, 2.6%, and 9.4%, respectively. The high rejection of methylene blue is mainly governed by the electrostatic repulsion between cationic COF channels and the positively charged dye. Moreover, the size sieving effect dominates the rejection of dyes with larger molecular sizes than that of the COF channel. These findings provide strategies for developing various nanoporous COF membranes for efficient dye/salt separation.

Developing water resiliency solutions at military installations

Climate change, along with rising human water demands, has been projected to raise the vulnerability of available water resources and poses further risks to global water security. A challenge of this century will be to secure enough fresh water for the world’s increasing population. U.S. Army installations provide critical support to Army’s mission. Army facilities face many risks which must be overcome to ensure that vital missions continue. Installation Energy and Water Plans (IEWPs) comprise one pivotal effort to ensure that facilities maintain access to the resources they need and can meet resilient solutions to maintain water supplies to sustain the people and environment. An essential component of the IEWP is the development of potential solutions, or courses of action (COAs) to address deficiencies that can improve an installation’s baseline condition, ensuring energy and water (E&W) security and resiliency. The undertaking seeks to improve security and resiliency by considering the varied threats of disruption within installations and providing measures for adaptable recovery. These disruptions include environmental events, droughts and climatic events, spills, and water security threats. Increasing energy and water resiliency aims to maintain that Army’s mission is successfully carried even if sources of water are cut off or compromised. The objective of this paper is to document water resiliency improvements in military installations by applying priority facilities demand estimation planning tools and reviewing courses of action and also providing lessons learned and tools that could be utilized for planned communities or city-based water management efforts. The IEWP process empowers stakeholders to improve military readiness through state-of-the-art solutions for enhanced security, resiliency, and mission assurance. These methods and use of standardized data sets could be pursued to be applied towards a broader scope of stakeholders to improve water resiliency for cities, communities, and industries outside of the military.

Global water security: A shining star in the dark sky of achieving the sustainable development goals

The COVID-19 pandemic has already triggered global health, economic, and social crises, clouding the sky of achieving the 2030 Agenda for Sustainable Development adopted by the United Nations (UN) in 2015 to improve human lives while protecting nature. Water, vital for all forms of life, is essential to public health and human well-being and smooth the path of ending poverty through food and energy security. Hence, we argued that global water security can serve as a shining star to guide policymakers through the overwhelming task of achieving the UN 2030 Agenda for Sustainable Development, currently hindered by the coronavirus outbreak. To quickly attain global water security while taking the accelerators of Sustainable Development Goal 6 (SDG6 “Clean Water and Sanitation”) into account, this study proposed different water-related interventions. To successfully implement the UN 2030 Agenda for Sustainable Development after the coronavirus pandemic, we call for immediate and sustainable interventions to act rapidly towards achieving water security and SDG6 worldwide and support the constant battle against the ongoing fight with COVID-19 and prepare for possible future pandemics.

Classifying Crop Types Using Two Generations of Hyperspectral Sensors (Hyperion and DESIS) with Machine Learning on the Cloud

Advances in spaceborne hyperspectral (HS) remote sensing, cloud-computing, and machine learning can help measure, model, map and monitor agricultural crops to address global food and water security issues, such as by providing accurate estimates of crop area and yield to model agricultural productivity. Leveraging these advances, we used the Earth Observing-1 (EO-1) Hyperion historical archive and the new generation DLR Earth Sensing Imaging Spectrometer (DESIS) data to evaluate the performance of hyperspectral narrowbands in classifying major agricultural crops of the U.S. with machine learning (ML) on Google Earth Engine (GEE). EO-1 Hyperion images from the 2010–2013 growing seasons and DESIS images from the 2019 growing season were used to classify three world crops (corn, soybean, and winter wheat) along with other crops and non-crops near Ponca City, Oklahoma, USA. The supervised classification algorithms: Random Forest (RF), Support Vector Machine (SVM), and Naive Bayes (NB), and the unsupervised clustering algorithm WekaXMeans (WXM) were run using selected optimal Hyperion and DESIS HS narrowbands (HNBs). RF and SVM returned the highest overall producer’s, and user’s accuracies, with the performances of NB and WXM being substantially lower. The best accuracies were achieved with two or three images throughout the growing season, especially a combination of an earlier month (June or July) and a later month (August or September). The narrow 2.55 nm bandwidth of DESIS provided numerous spectral features along the 400–1000 nm spectral range relative to smoother Hyperion spectral signatures with 10 nm bandwidth in the 400–2500 nm spectral range. Out of 235 DESIS HNBs, 29 were deemed optimal for agricultural study. Advances in ML and cloud-computing can greatly facilitate HS data analysis, especially as more HS datasets, tools, and algorithms become available on the Cloud.

Land subsidence and rebound in the Taiyuan basin, northern China, in the context of inter-basin water transfer and groundwater management

The freshwater scarcity and sustainability of overexploited aquifers have been recognized as a big threat to global water security for human development. Consequently, much research has focused in the past on negative consequences of groundwater abstraction, but somewhat less has been documented about the impacts of adequate management practices to address water shortages. Here, using an integrated analysis of InSAR displacement data, groundwater, and geophysical modeling we show how combined management provisions and inter-basin water transfer project has affected the aquifer system in Taiyuan basin in North China. Following groundwater recovery, the alleviation of land subsidence was found with rates being reduced by up to ~70% in the period 2017–2020 with respect to the period 2007–2010. The increase in pore pressure caused by rising groundwater in Taiyuan city, north of the basin, turned four subsidence centers with rates exceeding 110 mm/yr in the 1980 to uplift centers with rates up to +25 mm/yr between 2017 and 2020. A simple linear elastic model for homogenous subsurface properties can explain InSAR-measured surface displacements well. In the central basin, we found a significant seasonal displacement with annual amplitude up to 43 mm (negative peak in autumn and positive peak in spring) related to the groundwater recharge and discharge due to agricultural pumping irrigation. Using cross-wavelet method, we showed a relatively short time lags (less than one month) between surface deformation and water level changes in the central basin, indicating the low-permeability clayey units have a limited influence in delaying the compaction of aquifer system. Quantifying the effects of adequate groundwater management measures and large-scale engineering approaches like inter-basin water transfer to recharge pumped aquifers provide insight for local governments and decision-makers to properly evaluate the impacts of their policy in recovering the sustainability and efficiency of aquifers in water-deficient basins.

Polymeric Hydrogels—A Promising Platform in Enhancing Water Security for a Sustainable Future

AbstractAlthough water is essential for global health and the socio‐economic development of modern society, providing fresh water universally in a sustainable and affordable manner, for both developing and industrialized communities, is challenging. Polymeric hydrogels have recently drawn increasing interest as promising material platforms to sustainably enhance global water security. This review aims to provide a consolidated overview of polymeric hydrogels as an enabling agent in various water treatment technologies. First, a summary of the different approaches for the preparation of hydrogels with tailored chemistry, morphology, structure, and functions that enable the multifaceted requirements of different water technologies to be met is presented. Then, a set of properties unique to hydrogels, which gives them competitive advantages compared to other materials in the context of water treatment, is presented and discussed. This is followed by a comprehensive review of the applications of hydrogels in different water technologies. Their performance is correlated to their unique properties in order to gain an in‐depth mechanistic understanding of how hydrogels can lead to impressive performance and technological innovation. The authors conclude with some proposed solutions and recommendations for prospective research directions to address the remaining challenges specific to each hydrogel‐enabled water technology.

Optimization of well field management to mitigate groundwater contamination using a simulation model and evolutionary algorithm

Groundwater represents the most important available freshwater reserves and is of critical importance to global water and food security. Old environmental burdens that have led to the spread of contaminants in groundwater limit its use, thus interventions to mitigate contamination must often be carried out to ensure a safe drinking water supply. This study presents the optimization of well field management designs to reduce the desethylatrazine (DEA) concentration in the deep wells of the Brest Water Works (Central Slovenia). It investigates artificial recharge by injection wells using water from the nearby river and elaborates five well field management scenarios prioritizing different objectives. A multi-objective simulation-optimization framework was developed. A transient groundwater flow and solute transport model was applied to simulate the effects of the proposed recharge and pumping regimes. The shuffled complex evolution method was used to identify optimal values of well field management variables (location of injection well(s), minimum required injection rate, maximum pumping rate from production well) in the proposed scenarios. Model simulations showed that optimized well field management designs can significantly reduce DEA concentration in production wells (below 0.05 μg/L), assure compliance with water quality standards with (26%) reduced injection rate, and, with the implementation of two injection wells, achieve lower DEA concentration and higher pumping rate (up to 27 L/s). The optimization solutions depend on the defined well field management priorities and reveal a trade-off between the objectives (reduction of DEA concentration, increase of pumping rate, and reduction of injection rate). The impact of management variables on mitigation efficiency is not uniform and largely depends on the location of the injection well(s), which increases the complexity of mitigation design. The study has shown that the presented approach can be efficiently used for finding optimal mitigation designs and supporting water managers with information for planning mitigation measures.