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This paper aims to examine methods of artisanal and small-scale mining (ASM) in Ghana, map their perceived impacts on water resources, and analyse the implications of these perceptions for meeting the targets related to Clean Water of the United Nations Sustainable Development Goal 6 (SDG 6). The paper draws on 74 interviews with artisanal and small-scale gold miners and other stakeholders to investigate communities' perceptions of the effects of ASM methods (alluvial mining, surface/open-pit mining, and underground mining) on water bodies. We find that different ASM methods impact surface and groundwater in distinct ways while concurrently having a synergistic negative effect on water bodies. Stakeholders – including community leaders – perceive that the mining methods employed in ASM cause various forms of environmental degradation – thus affecting progress towards SDG 6, target 6.3 (water quality) – and severely hinder the availability of clean water for domestic and agricultural purposes, thus endangering the livelihoods of communities and affecting progress towards SDG 6, target 6.4 (sustainable water use). The community perceived impacts of ASM activities on water resources have implications for community acceptance of formalisation efforts in Ghana. We contend that a better understanding of these perceived impacts can help shape the country's policy for achieving the targets of SDG 6 in relation to Clean Water by 2030. In particular, we propose that the integration of the Community Mining Scheme as part of formalisation efforts of informal gold mining in Ghana not only responds to SDG 6 target 6b (participation of local communities in water management) but also has the potential to reverse the current large-scale mining 'bias' in policy, while addressing the galamsey challenge that contributes to the increasing impact of informal gold mining on SDG 6, targets 6.3 and 6.4. • There is a nexus between ASM methods (alluvial, surface/open pit, and underground mining) and their impacts on water resources. • ASM methods impact surface and ground water in distinct ways. • Formalisation policy and ASM methods have implications for achieving the targets related to SDG 6, Clean Water and Sanitation. • The Community Mining Scheme (CMS) in Ghana has the potential to challenge the large-scale mining 'bias'. • The CMS provides directions for other African countries which face similar ASM concerns such as the formalisation hurdles. [ABSTRACT FROM AUTHOR]

• Numerous science and policy debates occur over efficient aquifer protection measures. • This paper formulates a basin scale hydroeconomic optimization framework. • Its application is to North America's Middle Rio Grande Basin. • It discovers least cost aquifer protection measures for handling climate water stress. • Results are presented showing the marginal and total cost of aquifer protection. Where surface and groundwater are managed conjunctively, the stress on water supplies from climate change can significantly influence water use patterns as well as the economic value and sustainability of those uses. However, aquifer protection can be an expensive proposition because water uses that currently rely on aquifer pumping may produce considerable economic value that would be lost if protection measures are carried out. Evidence from climate-stressed regions has attracted research addressing the costs and benefits of aquifer protection plans. Despite these efforts, few peer-reviewed papers have examined water use patterns that minimize the economic costs of aquifer protection. This work presents an original approach to address that gap by developing and applying a basin scale hydroeconomic optimization model of North America's Middle Rio Grande Basin to explore impacts of new policies not yet implemented supporting aquifer protection. It also gives model access to readers or stakeholders to experiment with their own scenarios to assess impacts of alternative aquifer protection plans. The model accounts for surface and groundwater storage, irrigation, urban, environmental, and recreational demands, surface water inflows under various climate scenarios, groundwater pumping and recharge, substitute water prices, crop water use, evaporation, as well as institutional constraints governing water use. The objective is implemented by finding the optimized discounted net present value of economic benefits summed over uses, sectors, and regions from use of surface water and connected aquifers. Results are shown for each of six water supply scenarios, two substitute water prices, and two system operation rules. To address impacts of aquifer protection targets, groundwater sustainability targets are specified and enforced as constraints for each of the region's two major aquifers. We assess total and marginal cost of achieving two targeted aquifer protection levels by identifying optimized surface use and groundwater pumping for each of 24 scenarios. Results show that climate change, in the form of reduced and highly variable inflows, considerably drives up the cost of protecting aquifer sustainability, amplified by the conjunctive nature of the system. Future work points to a need to assess economic performance of various water conservation measures as well as reducing costs of substitute water through measures such as technical advance in desalination, recycling and reuse, substitution of other resources for water, better characterization of existing aquifers, and development of new groundwater supplies. [ABSTRACT FROM AUTHOR]

— Seasonal and location dependence of renewable energy resources have limited their applications in power generation. Energy storage systems are promising solutions to the intermittence of renewable energy resources. Rural electricity grids are faced with economic sustainability challenges due to low power demand and poverty. A rural grid design around economic drivers like agriculture and micro industries can mitigate poverty and improve economic sustainability of rural grids. This paper presents an integrated design for photovoltaic power generation with a pumped hydro storage system for irrigation and community utilization. The design explored the natural availability of water body in an elevated settlement area that offers a natural storage height for hydro energy storage. A photovoltaic generation plant was designed to power a pump as a turbine system for water storage and generation. HOMER® energy simulation software was deployed in the simulation. The result shows a satisfactory net present cost for the possible integration of a pumped hydro storage system in a photovoltaic generation plant as the most viable option to provide power at a power supply probability of 99.9% and water for irrigation. The benefits from the irrigation and water supply will enhance the community's socio-economic development and sustain the investment. [Display omitted] • We proposed a strategy to help an African community to have access to electricity. • The scheme will provide irrigation facilities and water supply to the community. • Photovoltaic Generation System was deployed as the primary energy source. • Intermittence of renewable energy was addressed through pumped hydro storage. • The result shows a satisfactory net present cost and 99.9% power supply probability. [ABSTRACT FROM AUTHOR]

• Stackelberg-Nash and Cournot-Nash games are applied to gain optimum strategies. • Uneven precipitation and stream inflow are characterized as fuzzy random variables. • An interactive-dynamic-programming-based genetic algorithm (IDP-GA) is designed. • An emergency response mechanism based on different climatic scenarios is developed. Increasing water demand aggravates water scarcity in water-scarce regions (e.g., India, Pakistan, and China), where uneven precipitation increases the risk of maintaining sustainable eco-economic development. Ignoring precipitation's effects leads to misguided policy recommendations that either deplete or underuse basin water resources. Therefore, this paper highlights the concept of uneven precipitation and uncertain stream inflow based on scenario analysis. Within a river basin, the regional authority and subarea managers both have water allocation and reallocation privileges. Motivated by sustainable development of water resource management systems, we argue that regional authorities should focus on alleviating the contradiction between supply and demand, and then seeking an optimum allocation strategy to ensure societal and economic benefits for its subareas, from which the subareas can provide reasonable reaction strategies. Authorities dominate water transactions between subareas involved in water rights distribution. This paper proposes a multi-objective multi-stage Stackelberg-Nash-Cournot (m2SNC) game model to cope with conflicts between regional authorities and subarea managers concerning multiple activities. An interactive-dynamic-programming-based genetic algorithm (IDP-GA) is designed to simulate the policies needed for the optimum allocation of water resources under various climate scenarios. The significant stress caused by unsustainable water resource allocation has been a perplexing problem for Sancha Lake, an important area in the southeast basin of the Dujiangyan Irrigation System in China. To identify the tradeoffs among stakeholders, we apply the proposed model to this basin. To gain further insight into climate change and water usage sustainability, we simulate the varying spatial and seasonal distribution of stream inflow based on historical climate data and propose different water management strategies for normal, slight drought, moderate drought, and serious drought conditions. This creates an emergency response cooperative mechanism based on different climate scenarios for developing countries that need to cope with water deficiency and uncertain situations. [ABSTRACT FROM AUTHOR]

This paper engages in a normative analysis of water security, in view of the sustainable development goals (SDGs) and the call for transformation. It examines the role of river basin organizations (RBOs) and integrated water resources management (IWRM) to water governance, and the extent to which they are consistent with water security for development in Southern Africa. The paper uses Policy Coherence for Development (PCD) and addresses essential questions regarding the extent to which RBOs in the Southern African Development Community (SADC) insofar as concerns SDG 6 achieve water security for people at the grassroots. The theoretical contribution of the paper includes the comparative examination of normative PCD and water security structures at RBO level in Southern Africa, and the extent to which RBOs reflect IWRM principles. Empirically, the paper highlights regional water policies regarding harmonization and coordination in the respective riparian states of and the RBOs, in line with the SADC's developmental objectives. As RBOs seem to prefer conserving, developing and utilizing water resources over people, they would do well to shift their focus on to people by adopting normative PCD, if they are to witness transformation. This would also be consistent with regional goals, which seek to bring the transformation agenda to the ground. • The SDGs suggest that development should be realized through "transformation". • Theoretically, normative PCD and water security are compared, and how far they reflect IWRM principles. • Empirically, harmonization and coordination of water policies of riparian states in basin organizations are highlighted. • SADC's commitment to IWRM integrates core values essential for transformation in some of its key policy documents. • The core values have not been translated into SADC river basins' water resources management strategies. [ABSTRACT FROM AUTHOR]

With the rapid urbanization and industrialization, urban and rural transformation development is inevitable, although rural transformation may suffer from a continuously widening gap. Thus, this paper describes a model to measure the rural transformation development path used to analyze the process more clearly, through measuring rural transformation, detecting influencing factors, and calculating the acting forces of factors. (1) The degree of rural transformation development in Fuping County, which has always been lower than in adjacent counties, gradually improved from 1990 to 2015. This study presents the temporal and spatial influencing factors, including the per capita industrial output value of enterprises above a designated size (x 5 ), the population density (x 8 ), and the per capita water resource (x 12 ) of six counties near to Fuping County. (2) The pull forces in these six counties were larger than the push forces, including society, economy, and resources, which indicates that rural development in Fuping County was mainly dominated by external factors. (3) This paper suggests to increase small scales and to extend large scales to improve the path measurement model by analyzing the test results for Fuping County; furthermore, proposals are presented for realizing rural sustainable development of Fuping County in terms of policy, industry, and resources. [ABSTRACT FROM AUTHOR]

The grand challenge of accessing fresh water and sanitation is a global concern. The intensity of challenge depends on the geographical location as well as the level of socio-economic development of individual countries. The present paper first reviews the key water-related global trends and examines the global agenda on water issues. Next the focus is turned on Russia. Despite of being one of the water-rich countries in the world, Russia faces a number of substantial administrative and structural issues in the water sector. Therefore, it is crucial to develop a long-term strategy for the management of this infinite, but strategic resource. The present paper develops long-term scenarios and strategies for the Russian water sector towards the year 2030. The study draws upon an earlier horizon scanning activity that identified a set of global trends and uncertainties related to water sector. This horizon scanning work is extended into alternative futures for the Russian water sector by using a combination of Foresight methods including scenario analysis, data mining, and various expert methods. Scenarios developed are characterized by a set of qualitative and quantitative factors and indicators of future developments in three key domains for the water sector: (i) the sustainability of water systems; (ii) water use by households and industry; and (iii) new water products and services. Scenarios present four alternative trajectories for the water sector that may also be applied for certain countries whose water sector is comparable with the Russia. Among the scenarios developed in the study, it is concluded that the most probable ones are Problem conservation and Losses and accidents . However, there is a possibility to revert these scenarios into more desirable trajectories, which are presented in other scenarios. For instance, a variety of new clean water technologies may be widely applied to achieve the Nearly perfect future (visionary) scenario. [ABSTRACT FROM AUTHOR]

Scarce water resources are one of the major constraints to achieve more food production. Food production needs therefore also to be evaluated in terms of water consumption, besides the conventional unit of land. Crop Water Productivity (CWP) is defined as the crop yield per unit of water evaporated. Contrary to crop yield, local benchmark values for CWP do not exist. This paper shows how operational earth observation satellites can measure CWP indirectly on a pixel-by-pixel basis, which provides an opportunity to define local, regional and global benchmark values. In analogy to a grading system for earthquakes (Richter) or wind force (Beaufort), a grading system for CWP is introduced: the Water Productivity Score (WPS). A regional scale WPS and a global version - Global Water Productivity Score (GWPS) - are presented. Crop yield zones are used to reflect local production potential, which reflects also the presence of irrigation systems besides general physio-graphical conditions. The 99 th percentiles of climatic normalized CWP values at global scale are 2.45, 2.3 and 4.9 kg m − 3 for wheat, rice and maize respectively. There is significant scope to produce the same - or more - food from less water resources, provided that locally specific best on-farm practices are implemented. At the upstream level, Governments can use (G)WPS to define national water and food policies and use it as a means to report to the Sustainable Development Goal standards. At the downstream level, WPS helps to improve on-farm water management practices by growers, both for rainfed and irrigated crops. While the current paper is based on wheat, rice and maize, the same framework can be expanded to potatoes, sugarbeet, sugarcane, fruit trees, cotton and other crops. [ABSTRACT FROM AUTHOR]

Policy making is a highly interactive process with environmental systems. Evaluation of policy's potential environmental impacts has been regarded as an efficient precautionary measure to avoid unexpected losses and environmental risks. One of the greatest challenges is how to streamline the policy-making process through an integrated evaluation approach. This paper formulated a process-based framework for environmental impact assessment of policy making (PB-EIA), by integrating policy problem identification, environmental impact assessment, and policy cost-effectiveness evaluation. Using China's wastewater resource utilization (WWRU) policy as a case study, the institutional, technological, and economic constraints or limitations related to wastewater resource utilization were identified, and the potential environmental impacts of policy implementation on energy consumption and carbon emissions were evaluated. The expected ecological and environmental benefits of the WWRU policy were supposed to be significant, and the cost of recycled water was relatively low compared with other unconventional water resources in China. Furthermore, significant variations in the environmental impacts and policy effectiveness were found across different sectors and regions. According to the evaluation results, some recommendations for supporting policy improvements and follow-up policy implementations were proposed. The specific technical procedures and application of PB-EIA were also discussed. This study demonstrates that the process-based framework can effectively incorporate environmental considerations into policy-making processes and promote sustainable development. • A process-based framework for environmental impact assessment of policy making (PB-EIA) was formulated. • The PB-EIA integrated policy problem identification, environmental impact assessment, and cost-effectiveness evaluation. • The PB-EIA framework was adopted in China's wastewater resource utilization (WWRU) policy evaluation. • The PB-EIA can help to integrate environmental considerations into policy making processes for sustainable development. [ABSTRACT FROM AUTHOR]

Intelligent prediction of water quality plays a pivotal role in water pollution control, water resource protection, emergency decision-making for sudden water pollution incidents, tracking and evaluation of water quality changes in river basins, and is crucial to ensuring water security. The primary methodology employed in this paper for water quality prediction is as follows: (1) utilizing the comprehensive pollution index method and Mann-Kendall (MK) trend analysis method, an assessment is made of the pollution status and change trend within the basin, while simultaneously extracting the principal water quality parameters based on their respective pollution share rates; (2) employing the spearman method, an analysis is conducted to identify the influential factors impacting each key parameter; (3) subsequently, a water quality parameter prediction model, based on Long Short-Term Memory (LSTM) analysis, is constructed using the aforementioned driving factor analysis outcomes. The developed LSTM model in this study showed good prediction performance. The average coefficient of determination (R2) of the prediction of crucial water quality parameters such as total nitrogen (TN) and dissolved oxygen (DO) reached 0.82 and 0.86 respectively. Additionally, the error analysis of WQI prediction results showed that >75% of the prediction errors were in the range of 0–0.15. The comparative analysis revealed that the LSTM model outperforms both the random forest (RF) model in time series prediction and demonstrates superior robustness and applicability compared to the AutoRegressive Moving Average with eXogenous inputs model (ARMAX). Hence, the model developed in this study offers valuable technical assistance for water quality prediction and early warning systems, particularly in economically disadvantaged regions with limited monitoring capabilities. This contribution facilitates resource optimization and promotes sustainable development. • Developed a multivariate water quality prediction model with some interpretability based on LSTM network. • There was a strong nonlinear relationship between climate change factors and several water quality parameters. • Strong R2 scores (0.82, 0.86, and 0.79) were achieved for TN, DO, and WQI prediction. • The prediction model showed high potential in future water environment monitoring and supervision. [ABSTRACT FROM AUTHOR]

China has been facing increasingly severe water scarcity that seriously threatens the socio-economic development and its sustainability of this country. This paper is intended to analyze and assess the water security of China. It first attempts to characterize the current status of water security within a risk-based, integrated framework that encompasses five key aspects critical to water sustainability, including water availability, water use patterns, wastewater generation and pollution control, water institutions and management, and health of aquatic systems and societal vulnerability. Based on the above assessment, the paper then analyzes emerging challenges for water security brought by climate change, population growth and rapid urbanization, and the water-food-energy nexus. In the end, the paper discusses China's future prospects on water security, including current achievements, government actions and policy initiatives, and recommendations for management improvement aimed at increasing water security. [ABSTRACT FROM AUTHOR]

Nuclear power technology (NPT) perception and acceptance have globally emerged as the most critical questions for the successful integration of NPT into any national energy mix. In its combination with seawater desalination, NPT provides a sustainable alternative for the security and economic efficiency of both energy and fresh water supply, the latter of which has been identified as "the bloodstream of the biosphere". Integrating econometric analysis into energy research with social science ramifications, this paper relies on bivariate ordered probit regression to study the impact of youths' interests in the biosphere on their awareness and optimism toward NPT in the UAE. The model is estimated using maximum likelihood methods, with the results showing each level increase in UAE youths' biospheric interests, to increase their NPT awareness by 13.5%, while conjointly reducing their optimistic expectations toward the technology by 2.4%. In addition, awareness and expectations about NPT are found to vary heterogeneously across the seven Emirates of the country. Moreover, accounting for all relevant factors (including respondents' biospheric interests), formed expectations about NPT are not significantly shaped by NPT awareness. Given that the first unit of the UAE's nuclear power plant "Barakah" just became operational in August 2020, our results provide important insights for evidence-based policy making to sustain the nascent nuclear energy program in the long run. [ABSTRACT FROM AUTHOR]

The increasing pressures of global warming, population growth and epidemic occurrence are causing challenges in meeting the growing requirements for water, energy and food. In particular, the contradiction between the supply and demand for water, food, and energy is exacerbated by inefficient resource utilization and carbon emission increase. Incorporation of the interlinked aspects of water, energy, food and carbon emissions from agricultural systems into one water-food-energy-carbon nexus facilitates integrated resource management. Biochar application to farmland is a potential strategy for carbon management and agricultural productivity improvement. The integration of biochar systems and the water-food-energy-carbon nexus is an efficient and coordinated alternative method for sustainable agricultural management and a crucial strategy for addressing water, energy and food security issues. Accordingly, this paper proposes an approach for the synergistic regulation of water, land, energy, and carbon emissions in a circular agricultural system by balancing water supply and demand, land allocation, electricity consumption, and economic upgrading principles. A two-stage circular agriculture framework is constructed, with biochar and electricity generated from agricultural residues at the first stage and employed at the second stage. Economic-environmental-energy harmonization is considered in the methodology, and the agrotechnical potential of biochar is quantified via crop yield increase and greenhouse gas emission reduction functions. This approach can assist decision makers in providing the best policy options given certain agricultural resources to achieve the maximum economic performance of the system while minimizing environmental side effects. In this paper, the model framework is applied to the Sanjiang Plain in northeastern China to verify the feasibility of the approach. The results indicate that the external electricity demand is reduced by 87.8% due to the generation of biofuels. Cropland greenhouse gas emissions are reduced by 34.09%–67.06% via the application of biochar. This study proposes an optimization method with important implications for the improvement of regional cropland management techniques and development of sustainable circular agriculture. This methodology can be extended to other agriculture-centered regions with limited resources and environmental problems. • Carbon cycle is integrated in agricultural water-food-energy-carbon (AWFEC) nexus. • An AWFEC nexus based model is developed for agricultural resources recycling. • Biochar and electricity are optimized sustainably for circular agriculture. • Analysis of resources recycling on economic-environmental balance is performed. [ABSTRACT FROM AUTHOR]

In recent times, product engineers have been under pressure to produce new strategies toward sustainable development, whether it involves materials or component recovery. The trend of product design development is shifting from ‘cradle-to-grave’ to ‘cradle-to-cradle’ which leads to the advent of multiple generation product life-cycles. This paper studies the design guidelines from Design for X which provides directional criteria on designing for multiple generation life-cycles. Therefore, in this paper, Design for Multiple Life-Cycles is defined as a combination of eco-design strategies including Design for Environment and Design for Remanufacture, which leads to other design strategies such as Design for Upgrade, Design for Assembly, Design for Disassembly, Design for Modularity, Design for Maintainability and Design for Reliability. This multiple life-cycles design thinking will pave the way for a more sustainable design and development of future products. [ABSTRACT FROM AUTHOR]

• State of the art studies on HDH desalination cycles were reported. • Different HDH-based refrigeration, power and multi-generation cycles were reviewed. • Integration of reported HDH cycles with various desalination methods were examined. • A detailed comparison was drawn in terms of performance criteria of these systems. Water and energy supply are two of the key issues human beings must address to attain sustainable development. Humidification-dehumidification technology has been proven to be a cost-effective approach to fulfill the freshwater demand. Particular attention has been given to coupling the humidification-dehumidification cycles with refrigeration, power and other desalination technologies with the aim of enhancing the performance of the combined cycle as well as increasing the amount of produced freshwater, cooling effect, power, etc. This paper provides a comprehensive review of the state-of-the-art investigations in terms of humidification-dehumidification technologies and their integration with the aforementioned cycles. In other words, an attempt has been made to categorize and discuss the various combined cycles based on humidification-dehumidification technology. A detailed comparison has been drawn regarding the performance criteria of the coupled cycles in terms of freshwater production, gained output ratio, and cost per liter. This comprehensive review lays the groundwork for future research concentrating on humidification-dehumidification based energy cycles. [ABSTRACT FROM AUTHOR]

Although construction of reservoirs and dams is one of the most common approaches to satisfy water demand and alleviate water scarcity, this approach severely affects river ecosystems. The most direct impact of human activities on rivers, for instance, regulating river can lead to degraded riverine ecosystems as part of the hydrological alteration. This paper determines the available ratio of water resource of natural or semi-natural rivers for ecological feasible regions using a method that transcends the traditional perspective of designed environmental flow. Our framework involves a modified percent of flow approach to identify the ecological feasible region of water resources utilization, which sequentially acts as a constraint for a reservoir optimization model based on the Cuckoo Search algorithm to obtain an optimal diversion process. Indicators of the hydrological alteration statistical method and the histogram matching approach are used to examine the framework's performance. The Han to Wei inter-basin water transfer project of China is selected as a case study. Results indicate that: (1) the allowable diversion rate with this modified percent of flow approach is more effective for reducing interference of diversion on the ecosystems than the conventional planned diversion rule; water demand, however, cannot be satisfied by the allowable diversion rate; (2) ecological feasible region is an accessible constraint for reservoir operation model, and the optimal diversion rate of such model is a trade-off output between the human water demand and the riverine ecosystems protection; and (3) increased allowable diversion rates alter flow indicators including the February flow, 30-day minimum flow, and low pulse count more appreciably than does the optimal diversion rate. This study provides key insights on how to achieve a trade-off between human water demand and riverine ecosystems protection, therefore contributing to the local sustainable development of social economy and ecological environment. • An ecological feasible region for river protection and water diversion was proposed. • An optimization model based on ecological feasible region was developed. • The optimal diversion rate integrating water diversion and riverine ecosystems protection was obtained. [ABSTRACT FROM AUTHOR]

Renewable energy sources can help combat climate change but knowing the land, water and carbon implications of different renewable energy production mixes becomes a key. This paper systematically applies land, water and carbon footprint accounting methods to calculate resource appropriation and CO 2 eq GHG emissions of two energy scenarios. The '100% scenario' is meant as a thinking exercise and assumes a complete transition towards bioenergy, mostly as bioelectricity and some first-generation biofuel. The 'SDS-bio scenario' is inspired by IEA's sustainable development scenario and assumes a 9.8% share of bioenergy in the final mix, with a high share of first-generation biofuel. Energy inputs into production are calculated by differentiating inputs into fuel versus electricity and exclude fossil fuels used for non-energy purposes. Results suggest that both scenarios can lead to emission savings, but at a high cost of land and water resources. A 100% shift to bioenergy is not possible from water and land perspectives. The SDS-bio scenario, when using the most efficient feedstocks (sugar beet and sugarcane), would still require 11–14% of the global arable land and a water flow equivalent to 18–25% of the current water footprint of humanity. In comparative terms, using sugar or starchy crops to produce bioenergy results in smaller footprints than using oil-bearing crops. Regardless of the choice of crop, converting the biomass to combined heat and power results in smaller land, water and carbon footprints per unit of energy than when converting to electricity alone or liquid biofuel. • The greenhouse gas emission savings of bioenergy entail large land and water use. • Land, water and carbon footprints of biofuels and bioelectricity are calculated. • A dynamic energy feedback loop is used to clarify gross and net footprints. [ABSTRACT FROM AUTHOR]

• Water use efficiency evaluation based on 3D water footprint using SBM model. • Two scenarios for water use efficiency evaluation. • Analyzing the driving forces affecting water footprint change using the LMDI model. Water shortage and the conflict between water supply and demand have become the main constraints to the sustainable development of sustainable societies in Beijing-Tianjin-Hebei (BTH) region. Scientific evaluation of water usage efficiency and clarification of the three-dimensional water ecological footprint (EF 3D) drivers are of great significance for the collaborative environmental management of BTH region. This paper firstly explores the evolution of water footprint breadth (EF size), depth (EF depth) and EF 3D in BTH region from 2004 to 2020. Using the super-efficient SBM (Slacks-Based Measure) model with EF 3D to evaluate the water use efficiency of BTH region in two scenarios. 22 impact factors were selected to analyze the dynamics affecting the change of EF 3D in BTH region by using the LMDI (Logistic Mean Divided Index) model. The results show that: (1) The water resources pressure of the three provinces are in the overload state from 2004 to 2020, and the EF 3D is at its maximum in 2011–2015. The EF depth of BTH region is fluctuating up and then fluctuating down around 2012, and the most serious capital consumption of water resources stock is in Tianjin. (2) The water resources in Hebei are all in inefficient use. The water resources in Tianjin are in a state of inefficient use in some study years, and since 2014, the water resources are in a state of fluctuating increase and high efficiency. As for Beijing, the water resources are in a state of efficient use in the study years. On the whole, scenario 2 better reflects the water resources utilization efficiency situation and is more in line with the real situation. (3) The water structure and endowment of water resources are pivotal factors positively influencing the EF 3D. To mitigate EF 3D and achieve sustainable utilization of water resources, both Hebei and Tianjin have ample room for progress in elevating agricultural water-saving technologies, optimizing industrial structure, and enhancing water usage patterns. Agricultural water consumption is no longer the primary driver of water resource depletion in Beijing, necessitating focused attention on the impact of external water diversions in terms of local water displacement, optimization of water usage structures, and their role in supporting socio-economic development. Additionally, excessive reliance on external water diversions may entail associated risks that warrant consideration. [ABSTRACT FROM AUTHOR]

The development of infrastructures in a sustainable manner ensures the preservation of human life. It means that societies should have constant access to clean energy and water resources. The focus on nexus planning and operation including renewable energy sources has covered the requirements for the development of sustainable integrated systems to provide secure energy and water while minimizing carbon footprint. However, the uncertainty of renewable energy resources challenges the operation of such integrated nexuses. In this regard, this paper proposes a risk-constrained operation of a sustainable energy-water nexus with the aim to reduce operational costs as well as carbon dioxide (CO2) emissions amount (t CO2). To supply the energy and water demands, a combination of renewable energy sources and desalination systems are considered. The downside risk constraint is proposed to investigate the impacts of risks of uncertainties associated with renewable energy production and electricity consumption as well as water demands. Electrical and water storage infrastructures are involved to increase the flexibility of scheduling and ensure affordability and sustainability. The problem is modeled as a mixed-integer programming problem resulting in optimal decision-making to manage the energy/water resources and storage systems to provide clean and safe energy and water with the minimum CO2 emission. For the emission sector, the carbon capturing and storing (CCS) technology is proposed to capture the CO2 defusing by the energy sector and resolve the carbon-related issues. To restrict carbon production, both CO2 taxes and cap policies are examined and the results showed that the latter has a considerable effect to incentivize the decision-maker to use CCS technology. [ABSTRACT FROM AUTHOR]

The pattern of virtual water trade within a region or region has a certain complexity. This paper uses multi-regional input-output models, local and tele-coupling theory, and geographical detectors to analyze the short-range and remote spatial pattern, change trends, and influencing factors of China's virtual water trade, which has essential research significance for the sustainable development and utilization of water resources. The results are as follows: (1) The water footprint and virtual water trade of each province in China are more likely to occur between the provinces close to each other, the local distance average distance is below 500 km, and the remote average distance is between 1100 km and 2000 km; (2) China's short-range inflow and outflow water footprint has always been the main dependent part of China's consumption and production end water resources, especially the local water footprint. The contribution of the remote water footprint has gradually been "replaced" by the short-range water footprint, and water resources only form a "small cycle" between the local and surrounding areas, becoming the main pattern of sustainable utilization of water resources in China; (3) The flow pattern of water resources in China still has a spatial imbalance and agglomeration effects. Regions with abundant water resources are net inflow and net import regions in both short-range and remote, and the net inflow and net outflow values in remote are higher than those in short-range; (4) The virtual water trade in all provinces of China tends to be close to each other. The "flow" in the trade network is mainly concentrated in the link path below 800 km. The interaction of various "flows" in short-range and remote virtual water trade results in fewer "flows" on one side and more on the other side in the industrial link path. Local virtual water trade has become an important guarantee and foundation for the utilization of water resources in all provinces and an important auxiliary to the total import virtual water trade; (5) The correlation of socio-economic factors to China's short-range and remote virtual water trade is higher than that of natural factors and scientific and technological factors. The interaction of factors contribution of a single factor more thoroughly and even far exceeds the sum of the contribution of two single factors, which can better explain the formation and change of near and long-distance virtual water trade patterns and flow on the link path. [ABSTRACT FROM AUTHOR]

The North China Plain is the main producing area of winter wheat in China. Due to the relatively poor condition of water resources, the competition of water between industry and agriculture is fierce. The increasing shortage of water resources has led to serious overexploitation of groundwater in some areas. Agricultural development is faced with severe challenges. In order to ensure regional food security and sustainable winter wheat planting, 52 cities of North China Plain (NCP), in the following of the paper, use the shorted name NCP，were taken as research units to analyze the matching characteristics of agricultural water and land resources, so as to reveal the direction of irrigated agriculture development and winter wheat suitable planting layout considering their balance in future. The paper firstly analyzed the cultivated area determined by water resource and irrigation development by agricultural available water, and then pointed out the direction of water-suited planting layout of winter wheat. The results showed that: 1) the Gini coefficient showed an increasing trend, which indicated that the area of cultivated land and irrigation area supported by water resources have nearly reached the upper limit. The large-scale extension of both cultivated and irrigation area is impossible under the restriction of water. 2) The amount of agricultural available water resources per unit of effective irrigation area and the effective precipitation increased gradually from north to south in the NCP, but the spatial distribution of water requirement of winter wheat in its growth period changed in the opposite way. This indicated the poor spatiotemporal match between winter wheat planting and water resources, leading to the cost of spending more water to maintain wheat production. 3), The further development of irrigation and the water-suited planting of winter wheat should pay attention to the southern part of the plain with rich water (such as southern Henan Province, Jiangsu Province, Anhui Province, etc.) to ensure the regional agricultural development. That is of great significance to the regional sustainable development, water shortage alleviation and national grain safety. ● Restraining the irrigation area and winter wheat in NCP. ● Moderately development irrigation area in south of the NCP. ● Water-suited planting layout of Winter wheat. [ABSTRACT FROM AUTHOR]

Abstract The rapid global growth in the use of renewable energy to reduce GHG emissions and mitigate climate change, through the inclusion of large amounts of PV and wind in existing electricity grids, has highlighted certain challenges. Most critically, their intermittent supply, necessitates flexible dispatchability from other generators in the grid. Currently, few renewable energy technologies offer this dispatchability, with only concentrating solar power (CSP) offering storage. CSP generates electricity from thermal heat, similar to fossil-driven thermal power plants, with the heat-source being inexhaustible concentrated solar irradiance. The thermal process, however, requires cooling, best achieved with a finite resource; water. CSP is ideally suited to areas of high solar irradiation, typically arid and water stressed. The need for water as a source of cooling is often neglected in the planning and development of CSP. This paper identifies water as a constraint to CSP deployment, and explores CSP's potential contribution to generation through the lens of the water-energy nexus. This aids our understanding of how water availability threatens expected CSP production capacity and places natural limits on its sustainable development. For strategic planning of CSP, we therefore propose the inclusion of integrated water resource management in CSP energy infrastructure planning. Highlights • Identify and explain the dependence of CSP on water as a limited resource. • Highlight disparity between co-location of high DNI and lack of water resources. • Highlight impact of variability of water resources on existing thermal power plants. • Identify lack of water resource consideration in CSP deployment planning. • Suggested integration of water resource management into CSP deployment planning. [ABSTRACT FROM AUTHOR]

Highlights • A multi-stage fuzzy stochastic model was developed in this research. • The developed model was applied for supporting water resources management. • Ecological water demand was considered and reflected in the developed model. • Multiple ways were adopted for dealing with multiple uncertainties. • It can contribute to in-depth analysis and sustainable development of water-resource- and eco- systems. Abstract In this paper, a multi-stage fuzzy stochastic programming (MFSP) method is introduced to deal with uncertainties presented as fuzzy sets and probability distributions. Moreover, it is able to reflect dynamics of uncertainties and the related decision processes through constructing a series of representative scenarios within a multi-stage context under a set of fuzzy α-cut levels. A management problem about long-term planning of water resources system has been studied to illustrate applicability of the proposed approach. With ecological water demand being considered, the framework solves the complex problems that can hardly be solved in previous individual model research and promotes sustainable development. The results indicate that the dynamic and complexity of water resources allocation can be reflected through the multilayer discrete context tree. Moreover, real-time correction for reducing the risk of water shortage and low economic penalty can be presented. They can also help identify satisfaction degree of the goal and feasibility degree of constraints in an interactive way, enabling decision makers to generate a series of alternatives under various system conditions. Overall, it can not only contribute to decision makers for in-depth analysis, but also for sustainable development of ecosystem. [ABSTRACT FROM AUTHOR]

The conventional desalination processes are not only energy intensive but also environment un-friendly. They are operating far from thermodynamic limit, 10–12%, making them un-sustainable for future water supplies. An innovative desalination processes are required to meet future sustainable desalination goal and COP21 goal. In this paper, we proposed a multi-effect desalination system operated with ocean thermocline energy, thermal energy harnessed from seawater temperature gradient. It can exploit low temperature differential between surface hot water temperature and deep-sea cold-water temperature to produce fresh water. Detailed theoretical model was developed and simulation was conducted in FORTRAN using international mathematical and statistical library (IMSL). We presented four different cases with deep-sea cold water temperature varies from 5 to 13 °C and MED stages varies from 3 to 6. It shows that the proposed cycle can achieve highest level of universal performance ratio, UPR = 158, achieving about 18.8% of the ideal limit. With the major energy input emanated from the renewable solar, the proposed cycle is truly a “green desalination” method of low global warming potential (GWP), best suited for tropical coastal shores having bathymetry depths up to 300 m or more. [ABSTRACT FROM AUTHOR]

Recent years have shown increased awareness that the use of the basic resources water, food, and energy are highly interconnected (referred to as a ‘nexus’). Spatial scales are an important but complicating factor in nexus analyses, and should receive more attention – especially in the policy-oriented literature. In this paper, we ‘unpack' the nexus concept, aiming to understand the differences between water, food and energy resources, especially in terms of spatial scales. We use physical indicators to show the differences in terms of absolute magnitude of production and the distance and volume of physical trade, for seven resource categories: water withdrawal, crops, animal products, bio-energy, coal, oil, and natural gas. We hypothesize that the differences in trade extent are related to physical characteristics of these resources: we expect high priced, high density, geographically concentrated resources to be traded more and over longer distances. We found that these factors, taken together, can explain some of the differences in trade extent (and thus spatial scale involved), although for each individual factor there are exceptions. We further explore the spatial scales by showing the bidirectional physical trade flows at the continental scale for crops, animal products, bio-energy and fossil fuels. We also visualize how nexus resources are directly dependent on each other, using a Sankey diagram. Since both direct dependencies and physical trade are present, we investigate the role of resource-saving imports, which is a form of virtual trade. The resource-saving imports highlight the importance of continental and global scales for nexus analyses. [ABSTRACT FROM AUTHOR]

Based on semi-structured interviews with key decision-makers from 38 distinct municipal water utilities in Oklahoma, this paper examines the innovation process that drives water system transitions in response to external pressures, including climate change, policy, and economic trends; and to address internal system needs, such as supply expansion and infrastructure upgrades. A multiple linear regression analysis reveals a strong, positive relationship between innovations and dynamic capabilities, suggesting that dynamic capabilities are crucial to the transition of water systems. The strength of the relationship between sensing, seizing and reconfiguring dynamic capabilities and innovations differs by type of innovation. Water manager awareness of the state-level Water for 2060 Act was shown to have significant influence on the number of innovations generated by municipal water systems, while water manager licensure level was not a reliable predictor of innovation. Recommendations for encouraging much needed radical innovations are outlined. [ABSTRACT FROM AUTHOR]

Improved infrastructure can deliver major benefits capable of achieving the Sustainable Development Goal to make cities and human settlements inclusive, safe, resilient and sustainable. Despite the importance of infrastructure in the functioning of African cities, there are few attempts at investigating its contribution from a city perspective. This paper investigates how the provision of infrastructure contributes to the prosperity of African cities, using Expert Opinion Survey from a diverse selection of cities. Trends in three components of infrastructure – water supply, road network and telecommunications are examined. Serious water shortage characterizes 79% of the African cities in the study. However, cities such as Gaborone and Algiers located in arid regions of Africa are better able to meet their water supply needs largely due to effective water governance and management. The dysfunctional nature of roads in African cities poses a major challenge to the prosperity of these cities. Compared to other components of infrastructure, telecommunications is ranked as the most developed form infrastructure in African cities. This is attributed to the spectacular growth in the mobile phone industry over the last one and half decades. The mobile phone industry acts a catalyst for growth in African cities. Further analysis of the Expert Opinion Survey shows that if developed and effectively managed, infrastructure can contribute to the prosperity of African cities by: driving economic growth; facilitating urban mobility; ensuring greater access to health and education; enhancing safety and security; guiding urban growth; enhancing environmental quality; improving slums conditions; and reducing intra-urban disparities. [ABSTRACT FROM AUTHOR]

The optimal biogas system design model (OBSDM) described in this paper is intended to be used as a decision-making tool to increase awareness of the potential of biogas technology for different applications in Sub-Saharan Africa (SSA). The decision-making tool identifies the most suitable biodigester design based on user defined inputs, including energy and fertiliser requirements; feedstock (type, amount, and rate of supply); water supply; land use (area, soil type, ground water level); climate (temperature and rainfall); construction materials available locally; and the priorities (based on sustainability criteria) of the intended biogas user. The output of the model provides a recommended design with estimates of the expected costs, energy and fertiliser production, and links to contact biodigester suppliers. In order to test the model, data from household surveys conducted in rural regions of Kenya and Cameroon were used as inputs to the model. An innovative fixed dome biodigester design, which uses stabilised soil blocks instead of bricks, was identified as optimal for both Kenyan and Cameroonian rural households. The expected performance of the optimal biogas system design from the model output was consistent with survey data on existing biogas systems in the region. [ABSTRACT FROM AUTHOR]

Assessing the evolution of the performance of water supply and sanitation services is essential to monitor progress towards the universalization of water services, as specified by the Sustainable Development Goal 6 of Agenda 2030, adopted by United Nations member countries. Brazil, a developing country with a continental size and geographical diversity, will face significant challenges to achieve this goal. The main objective of this paper is to evaluate the evolution of productivity of water supply and sanitation services in Brazilian municipalities in the period 2012–2019. The analysis also explores whether water services' performance is balanced across the country, with a specific analysis of performance at the macroregion level. From a methodological perspective, this research evaluates productivity change over time using a Malmquist Productivity Index estimated with a metafrontier, satisfying the circularity property. It also develops a pseudo Malmquist index that compares productivity levels across macro-regions. The results revealed a productivity loss of approximately 4% at the national level, with an unequal profile across the macro-regions. The Southeast municipalities stand out for exhibiting, on average, higher productivity levels than the South and Northeast municipalities. • The evolution of water services productivity is explored using a Malmquist index. • Productivity gaps across regions are assessed with a pseudo-Malmquist index. • Both South and Northeast regions have lost productivity in the decade studied. • The Southeast region presents the highest level of productivity growth. • The municipalities in the South exhibit homogeneous water services' performance. [ABSTRACT FROM AUTHOR]

• We establish three models based on water supply. • The model considers whether the water supply meets the demand. • The flow rate of primary canal is closer to the actual flow rate. • Ensure fairness as much as possible when water is insufficient. The optimization of canal water distribution is vital in irrigation areas because a reasonable distribution is required to improve the water distribution efficiency and maximize the benefits of water resources. In this paper, under the condition that the total volume and flow rate of water supply in the primary canal have been determined, the water supply is compared with crop water demand, and three optimal models of canal water distribution are established. In situation 1, the total volume of water supply is sufficient to meet the crop water demand during the growing period. In situation 2, the water supply is insufficient to meet crop water demand during their growth period; however, this problem is resolved by extending the water supply period. In situation 3, the water supply cannot meet the crop water demands during the growth period, even after adjusting the water supply period. Because the proposed water distribution optimization model is based on water supply conditions in irrigation areas, the irrigation area managers can easily develop their operation water distribution schemes. The model was validated using the Bojili irrigation area. Results showed that the model's calculated variation trend of the main-canal flow rate was similar to the actual flow rate, and irrigation area managers could meet the model requirements with a small adjustment in the actual flow rate. The model also considered canal leakage loss, timely water distribution, water distribution fairness, and other goals, potentially improving agricultural water efficiency and water distribution satisfaction as well as promoting sustainable agricultural development. The model presented here is universal and can be used in other irrigation areas. [ABSTRACT FROM AUTHOR]

Due to climate change concerns, various environmental stresses and social inequality among the people, the welfare of mankind is increasingly being viewed through the prism of sustainable development. Sustainable development is a highly multi-disciplinary field of research that has been extensively studied during last two decades. Therefore, from the beginning of the 21st century, a series of Sustainable Development of Energy, Water and Environment Systems (SDEWES) Conferences were founded to address sustainable development issues. This Journal of Cleaner Production Special Volume (SV) is dedicated to the 10th SDEWES Conference. The SV is focused on three main fields that are of strategic importance to sustainable development: energy issues, water issues, and environmental engineering and management. The division of selected papers according to the named research fields was established following the previous Journal of Cleaner Production Special Sections and Volumes dedicated to the SDEWES Conferences. Therefore, this Special Volume builds upon the previously generated SDEWES knowledge base. [ABSTRACT FROM AUTHOR]

The water crisis is one of three crises that are persecuting the world. China is among the countries that face severe water shortages. Water scarcity and water pollution have seriously affected China's sustainable development in terms of the economy and society. Water resources per capita of China is only one quarter of the world's average. In addition, about 70 percent of China's rivers, lakes, and reservoirs are affected by pollution. Due to limited water resources, a crucial issue for the sustainable development of the watershed is how to resolve the human/nature competition for water and how to achieve the coordinated development of the economy, society and ecology. On the basis of defining water consumption for production, living and ecology (WPLE), this paper proposes a framework for forecasting and optimally allocating WPLE. Using Zhangye, in the middle reaches of the Heihe River Basin as the case study area, we forecasted and optimally allocated WPLE under three development scenarios, i.e. the conventional development scenario (CDS), the economy-priority development scenario (EPDS) and the environmentally sustainable development scenario (ESDS). In 2010, the proportions of WPLE in Zhangye were 87.73%, 2.74% and 9.53%, respectively. In 2020, the proportions of WPLE will be 74.80%, 4.50% and 20.70% under the CDS, 76.16%, 5.27% and 18.57% under the EPDS, and 74.99%, 4.51% and 20.50% under the ESDS. In the future, the proportion of production water consumption of Zhangye will drastically decrease, while the proportion of ecological water consumption will significantly increase. The main contradiction of the co-evolution of WPLE of Zhangye is the competitiveness of production and living water consumption with ecological water consumption. [ABSTRACT FROM AUTHOR]

Poyang Lake suffers from a severe shortage of water, due to the construction of the Three Gorges Dam and other hydropower stations along the upper Yangtze River. In this paper, we propose a two-sector endogenous growth model to investigate the effects of extractive water use and impoundment activities on the optimal sustainable growth path. To offset the negative impact of the extractive use on the regenerative capacities of water resources, the impoundment activities should grow at a constant rate. We also provide a numerical example to illustrate the mechanisms of the endowment and the regenerative capacities of water resources on the long-run economic growth path. We find out some theoretical evidence to support the construction of a water conservancy project to restore regeneration capacities of Poyang Lake. [ABSTRACT FROM AUTHOR]

Ecosystems play a very important role in the sustainable development of remanufacturing. Research has often focused on the sustainability of remanufacturing systems from the aspect of general technological activities, for which there is a lack of an in-depth consideration of ecological services. This may lead to an imbalanced development of ecosystems. This paper proposes a full lifecycle-based sustainability evaluation model for remanufacturing ecosystem services (ESs) from the novel perspective of technology-ecology synergy. Firstly, by analyzing the coupling effect of technical activities and ecological services, a technology-ecology synergy in a lifecycle assessment (TES-LCA) computing model is established to quantify the sustainability of remanufacturing ESs. Secondly, the supply and allocation of ESs considering multiple users are proposed and addressed. Thirdly, regional differences in ESs are investigated. The sustainability of ESs is then analyzed and calculated on a multi-spatial scale. Finally, the feasibility of the proposed model is verified by performing a case analysis of the remanufacturing of a spindle of a machine tool that is to be adopted in two regions. The case study results showed that the air quality control service in both two regions is unsustainable; however, the water supply service is sustainable. The proposed model can provide data support for governmental policy makers and businesses to formulate relevant policies to maintain a balanced development of ecosystems. [Display omitted] • Assess the remanufacturing sustainability from the technology-ecology synergy view. • The multi-user allocation accounting strategy of ecosystem services is established. • The regional difference in ecological services is considered. [ABSTRACT FROM AUTHOR]

The coal mine underground reservoir (CMUR) technology effectively solves the problem of "rich coal, poor water and weak ecology" in the mining areas of northwest China. This technology not only makes full use of underground space formed by coal mining, but also protects regional water resources. Water resources carrying capacity (WRCC) is an important indicator for characterizing the sustainable development of regional water resources and ecosystem. With the concept and technical core of " conductivity, storage and use" of CMUR as the entry point, this paper defines the concept of WRCC in the mining area. Based on the fuzzy comprehensive discrimination method, Focusing on stability and sustainability of the ecosystem in the mining area and fully considering geological factors, mining factors, water resource factors, this study constructs an evaluation system for the WRCC of the mining area under the influence of the coal mine underground reservoir based on fuzzy comprehensive discriminant method. Moreover, the evaluation criteria are formulated, and the membership functions and weights of 16 impact factors are derived. The transformation characteristics of WRCC with and without underground reservoir in Shendong mining area from 2009 to 2021 are evaluated CMUR, and the results show that CMUR improves the WRCC of the mining area, and supports the benign development of the regional ecosystem. The results of this study are of reference value and academic significance for the evaluation of WRCC in mining areas and the protection of water resources in ecologically fragile mining areas. [Display omitted] • The CMUR-WRCC evaluation system is constructed based on sustainable development. • The membership functions of influencing factors are established. • The CMUR promoted the benign development of the ecologically fragile mining areas. • The relation between CMUR and WRCC is studied, which remedy the blank in the field. [ABSTRACT FROM AUTHOR]

Satisfied the long-term demand for electricity and freshwater shortage in off grid and resource constrained areas through clean energy is particularly important in the context of comprehensive clean and green development. In this paper, a novel solar-driven freshwater-electricity cogeneration system was proposed, which has high efficiency solar-thermal-electrical conversion capability and outstanding thermal management performance. First, a solar-thermal-electrical coupling numerical model of the system was established, the energy transmission and transformation mechanism were analyzed, and the structural parameters such as the air gap and distillation stages were optimized to further improve the performance of the system. Second, guided by theoretical modeling, the outdoor experiment verified the outstanding thermal management performance through evaporative cooling of seawater and the efficient solar-electricity-steam conversion ability of the system. A photovoltaic module temperature was reduced to about 8 °C, as compared to the same photovoltaic module working alone. And the reduced photovoltaic module temperature led to a 0.86 % increase in average solar-electricity conversion efficiency. Meanwhile, a large amount of freshwater was obtained by consuming the waste heat of photovoltaic modules. The average water production rate was about 2.06 kg·m−2·h−1 under the real outdoor environment. Finally, the system has a stable self-cleaning ability without solid salt crystallization and efficient seawater desalination performance in freshwater production. Hence, this novel system not only realizes passive high energy transfer efficiency to produce freshwater and electricity, but also provides a strategy to solve the crisis of energy and water resources in the future. [Display omitted] • A novel freshwater-electricity cogeneration system was demonstrated. • A solar-thermal-electrical coupling model of the PV-MSSD system was established. • The maximum temperature drop of the PV module in the PV-MSSD device can reach 8 °C. • The solar-electricity and the thermal-steam efficiency can reach 16.78 % and 200 %. [ABSTRACT FROM AUTHOR]

Water security plays an important role in human sustainable development since the 21st century. This paper focuses on the water resource security in the karst areas of Guizhou province, China, to elucidate the stress mechanism and feedback relationship affecting water resource security sensitivity. Firstly, an assessment indicator system for water resource security is constructed with regard to the characteristics of water resources in the karst area. Secondly, according to the fuzzy mathematics theory, an assessment model for water resource security is constructed to dynamically evaluate water resource security in the karst area over a given time scale. Finally, to analyze the sensitivity and the stress mechanism of regional water resource security in the context of hydroclimate change, this paper establishes a system dynamics model, and sets four scenarios, namely, high flow year, normal flow year, partial dry year and dry year, to simulate and figure out the optimal scenario of regional water resource security. The results demonstrate that the integrated security of water resources in the karst area is highly sensitive in the context of hydroclimate change. In addition, the sensitivity of water resource security in the karst area would decrease from high flow year to dry year in the future. • Fuzzy mathematical and SD are used to measure water resource security. • From 2001 to 2015, water resource security eigenvalue increased from 2.03 to 4.65. • Water subsystems have diverse security sensitivity under hydroclimate change. • Water resource security sensitivity varies from dry year to high flow year. [ABSTRACT FROM AUTHOR]

[Display omitted] • A comprehensive method was used to explore the improvement path of water environmental carrying capacity (WECC) from both subsystem and index levels. • WECC in the YREB was generally low without upward trend and showed no spatial autocorrelation. • WECC of the downstream in the YREB was higher than that of upstream and midstream. • Coupling coordination among subsystems is a necessary condition for higher WECC. • Proportion of ecological environment water consumption has the largest restriction on WECC improvement in the YREB. Improving water environmental carrying capacity (WECC) is pivotal to support water sustainability and continued economic development. The improvement pathways of WECC based on both subsystem coupling and driving factors have not yet been identified. Therefore, taking the Yangtze River Economic Belt (YREB) as a case study, this paper firstly constructed a set of scientific comprehensive evaluation index system of WECC based on the coupling system of water resources-water environment-society-economy. Secondly, the improved catastrophe progression method was properly introduced to dynamically evaluate the level of provincial WECC from 2010 to 2018. Finally, the coupling coordination degree (CCD) and obstacle factor diagnosis model were creatively combined to identify the main influencing factors of WECC. The main findings were as follows: (1) The WECC of the YREB was generally low at the provincial and subsystem levels without any obvious upward trend. In comparison, the WECC was higher in Shanghai City, Zhejiang Province and the lower reaches of the YREB. (2) The CCD among the four subsystems was generally low in the YREB. Meanwhile, there was a significant positive correlation between the CCD and WECC in each provincial area, and thus the low CCD was a vital reason for the low WECC in the YREB. (3) Overall, the economic subsystem had the highest restriction on WECC improvement in the YREB, while that of the water resources subsystem had the least. Seen from the mean, the top five obstacle factors of WECC were proportion of ecological environment water consumption, urbanization rate, per capita GDP, proportion of tertiary industry and water consumption per unit of GDP respectively. Furthermore, the rankings of main obstacle factors showed a certain time fluctuation. In general, it could be found out that the CCD of subsystems and main obstacle factors should be focused on simultaneously when improving regional WECC. Additionally, this study has provided a new analytical framework for identifying the pathways of improving WECC, which is also applicable to find the improvement pathways for stability and safety of other complex systems. [ABSTRACT FROM AUTHOR]

Optimization of the industry structure is important for the sustainable development for developing countries, e.g. China. The inexact stochastic multiple objective programming (ISMOP) which integrates stochastic programming, interval linear programming, and multiple objective programming was applied to analyze the optimization of industrial structure based on water environmental carrying capacity in Huai River Basin within Shandong Province (HRBSP). ISMOP can effectively solve the uncertainty existing in the multiple-objective optimization model and provide the information of development patterns of different industrial sectors. Results showed that the growth rates of output values from secondary industries under different q i values in the planning stage (2010–2020) will be almost 8%, and the total amounts of COD and NH 3 –N discharge will reduce by at least 65% from 2010 to 2020 in HRBSP. In term of the secondary industrial structure, the coal, paper-making and food processing industries, as the traditional backbone industries but with high risk of water pollution, should be reduced gradually; the beverage and textile industries should be strictly limited; and conversely, the new industries, such as metallurgy and construction material industries, should be allowed to maintain the rapid development. In the context of the aquatic environment protection in the basin level, the results based on ISMOP are useful for making policies to balance the economic development and water pollutant prevention within the Huai River Basin and other river basins. [ABSTRACT FROM AUTHOR]

This paper deals with the combined use of non-invasive technologies for a reliable and ready measures of soil physical parameters. In particular, time domain reflectometry (TDR) was deployed for soil moisture estimation in combination with geophysical investigations as electrical resistivity tomography (ERT) and ground penetrating radar (GPR). The investigation regarded two cultivars of dry bean ( Phaseolus vulgaris L.), a dry bean landrace and a common bean. The irrigation of these cultivars have been carried out by drip emitters placed on the bean rows, with different irrigation regimes based on crop evapotranspiration (ETc) demand calculated from the analysis of weather data. Geophysical surveys, basesd on ERT and GPR, were performed during the growth season along transects longitudinal and parallel to the bean rows with the aim to obtain soil images for the identification and characterization of crop roots locations. Data analysis of variance indicated that a reduction in the total irrigation amount of 50% of Etc demand ensures good conditions of soil moisture and does not determine significantly decreased production in the local bean genotype, probably because of its lower sensitivity to water stress. This confirms that the choice of autochthonous varieties well adapted to the local environment, could be a winning choice for the purpose of sustainable management of irrigation water. [ABSTRACT FROM AUTHOR]

In many arid and semi-arid regions of the world, the scarcity of water resources, increasing population and the experience of recent droughts are exerting great pressures on water resources. Climate change is anticipated to exacerbate the vulnerability of water resources, which clearly highlights the need for developing sustainable water management policies and appropriate adaptation strategies. In this paper, the likely impact of climate change on water availability indicators in a semiarid region is explored through a case study in a developing country. Queretaro River Basin (QRB ) in Central Mexico, is presented as an example of a semi-arid region that is facing growing pressures on the availability of water resources to sustainably meet social, economic and ecological needs. The output of seven downscaled Global Coupled Ocean-Atmosphere General Circulation Models (AOGCMs) for the B1 and A1B greenhouse gas emissions scenarios (GHGES) were used to investigate the likely impacts of climate change on water resources in the QRB. The computed future scenarios of climate change predict that increases in mean annual temperature ranging from 0.8 °C to 4.8 °C and decreases in mean annual precipitation ranging from 17% to 22% could result in a decline of up to 9.16% in the available water for groundwater recharge and runoff by the end of the 21st century. Results also suggest that for the future, both dry and wet events will become more severe and frequent, increasing the vulnerability of water resources and compromising sustainability. Therefore, it is advisable that water management planning considers flexible adaptation strategies in order to allow for adjustment under different scenarios of water availability, if the implementation of unbiased, efficient and economical water resources strategies is to enhance sustainability and resilience to climate change in the long-term. [ABSTRACT FROM AUTHOR]

Currently, more research to implement and monitor cleaner production practices for distribution and sustainable management of natural and alternative water sources to comply with the demands of the different users while preserving water levels are needed. In this paper, a periodic hourly-based model with meaningful parameters has been developed to analyze and forecast water demand as a function of time, thus enabling a better understanding of the consumption pattern and the condition of the pipe network. The model was tested by investigating the daily water consumption from selected categories of users which were isolated from different distribution networks in Sligo, Ireland. The flow data used was obtained in 15-min intervals and averaged in different time periods for analysis. In all cases, the model fittings obtained were highly consistent and all the parameters showed satisfactory confidence intervals ( α = 0.05), thus demonstrating the reliability of this approach. The model provides a quick analysis revealing the regularities of water demand that could benefit water utility managers and researchers: to obtain optimal regulation and pumping schemes; for planning and design purposes; to control unexpected scenarios that can take place during the distribution of water; the performance of water distribution systems; and to locate possible network failures. In addition, the model parameters can be used as standard criteria for water utilities to compare precisely the water demand between different areas, identify complex trends and analyze the pipe network for managing, auditing and monitoring purposes. [ABSTRACT FROM AUTHOR]

Reducing water losses is seen as key to sustainable water management, but turns out to be challenging. This paper applies a panel data analysis with fixed effects to assess the major drivers of non-revenue water, some of which are under the control of utilities and some of which are not. The analysis finds that the most important drivers are population density per kilometer of network and type of distribution network, which are mostly resulting from urbanization patterns which are factors mostly out of the control of the utility. Yet, low opportunity costs of water losses and high repair costs of water losses have an important adverse effect on water loss reduction. We also found that the country environment in which the utility operates has an important impact on non-revenue water levels. [ABSTRACT FROM AUTHOR]

Despite providing water-related services as the primary purpose of urban water system (UWS), all relevant activities require capital investments and operational expenditures, consume resources (e.g. materials and chemicals), and may increase negative environmental impacts (e.g. contaminant discharge, emissions to water and air). Performance assessment of such a metabolic system may require developing a holistic approach which encompasses various system elements and criteria. This paper analyses the impact of integration of UWS components on the metabolism based performance assessment for future planning using a number of intervention strategies. It also explores the importance of sustainability based criteria in the assessment of long-term planning. Two assessment approaches analysed here are: (1) planning for only water supply system (WSS) as a part of the UWS and (2) planning for an integrated UWS including potable water, stormwater, wastewater and water recycling. WaterMet 2 model is used to simulate metabolic type processes in the UWS and calculate quantitative performance indicators. The analysis is demonstrated on the problem of strategic level planning of a real-world UWS to where optional intervention strategies are applied. The resulting performance is assessed using the multiple criteria of both conventional and sustainability type; and optional intervention strategies are then ranked using the Compromise Programming method. The results obtained show that the high ranked intervention strategies in the integrated UWS are those supporting both water supply and stormwater/wastewater subsystems (e.g. rainwater harvesting and greywater recycling schemes) whilst these strategies are ranked low in the WSS and those targeting improvement of water supply components only (e.g. rehabilitation of clean water pipes and addition of new water resources) are preferred instead. Results also demonstrate that both conventional and sustainability type performance indicators are necessary for strategic planning in the UWS. [ABSTRACT FROM AUTHOR]

• A multi-system multi-layer theoretical framework is proposed for the first time. • Sustainable development measures was selected as indicators. • Improved TOPSIS model is used to evaluate the water resources carrying capacity. • Standard deviation ellipses were applied to analyze the WRCC orientation. • WRCC and GTWR model are combined for the first time. Water resources system (WRS), socio-economic system (SES) and Ecological environment system (EES) are systems closely related to the sustainable development of cities. It is crucial to accurately evaluate the Water resources carrying capacity (WRCC) and the Coupling coordination degree (CCD) among the systems for sustainable development. The paper proposed a conceptual framework of Water Resources Endowment-Support-Pressure-Development-Destructiveness-Protection-Promotion(WRESP2D2P) and constructed an index system with 20 indicators. The improved TOPSIS model and Geographic spatiotemporal weighted model (GTWR) were applied to evaluate the water resources carrying capacity and analyze the key factors affecting the WRCC. Findings showed that (1) CCD in 11 cities of HBP are in a state of reluctant coordination from 2011 to 2018. (2) Although the Water resources carrying capacity index(WRCCI) of 11 cities is increasing, Water resources carrying capacity grade(WRCCG) of most cities are in Grades III and IV, which is in a state of critical carrying state and slight overload. (3) Spatially, the distribution pattern of WRCC of HBP changes from Northeast to Southwest. (4) The factors affecting WRCC have spatial and temporal heterogeneity. (5) The per capita water resources is the most dominant factor affecting the WRCC in HBP. The study proposed a multi-system, multi-layer index system, aiming to provide a scientific basis for urban sustainable natural resources management. [ABSTRACT FROM AUTHOR]

The temporal and spatial dynamic change of energy water footprint reflects the use of water resources in the process of supplying energy. The spatio-temporal mismatch between energy and water resources in the Ji-shaped bend of the Yellow River has seriously restricted its development. In this paper, spatio-temporal variation in the water footprint of energy in the Ji-shaped bend of the Yellow River from 2000 to 2019 was characterized using the energy water footprint evaluation model. The spatial relationship between energy water footprint and regional water resources was analyzed using the standard deviation ellipse. Finally, the energy-water constraints in the study area were evaluated based on the water footprint stress index. The results were as follows. (1) The energy water footprint increased rapidly, and the energy structure has become more equitable. (2) The spatial distribution of energy water footprint is unbalanced, and the water footprint of fossil energy was higher in the east, but electricity was higher in the west. (3) Due to the growth of hydropower, electricity matches the available water resources to a greater extent than fossil energy. (4) The energy-water nexus is tense in the Ji-shaped bend of the Yellow River, so it is urgent to explore a sustainable transition path. Therefore, improving energy and water efficiency, optimizing the energy structure, and promoting low energy and water resource consumption patterns will be essential for facilitating sustainable development in the Ji-shaped bend of the Yellow River. • Comprehensively understanding the relationship between energy and water in China's energy rich areas. • Uncovering the temporal and spatial evolution characteristics of energy water footprint. • Discovering the spatial matching degree of regional energy and water. • Comparing the inter provincial energy and water constraints. [ABSTRACT FROM AUTHOR]

This paper presents a new methodology for optimal staged development of water supply systems that ensures robust and sustainable solutions. This problem is formulated as a multi-objective optimisation problem under uncertainty with objectives being the minimisation of average present value of intervention costs and greenhouse gas emissions, and the maximisation of supply robustness. The above methodology was validated and demonstrated on southern portion of the regional water supply system of Adelaide. The results obtained illustrate the importance of identifying optimal staged solutions to ensure robustness and sustainability of water supply into uncertain long-term future. [ABSTRACT FROM AUTHOR]

DAIAD is an FP7 research project addressing the challenge of improving the management of water resources through real-time knowledge of water consumption in order to improve societal awareness, induce sustainable changes in consumer behavior, and explore new water demand management strategies. In this paper we present the motivation of our work, our vision and objectives, along with an early architectural overview of the planned DAIAD system. [ABSTRACT FROM AUTHOR]

• A framework for country-scale water-energy-food security overall analysis is developed. • The developed approach integrated TOPSIS, Spearman and radar graph methods. • Method can promote water-energy-food security evaluation in data-limited countries. • Water-energy-food security and relationships in Central Asia is evaluated. • The factors reducing water-energy-food security in Central Asia are identified. Thoroughly understanding the security of water, energy and food (WEF) and the factors that influence them is essential for sustainable development management in any region. This study proposed a new analytical framework for WEF security evaluation in both individual sectors and the whole system, using the technique for order preference by similarity to an ideal solution (TOPSIS) and four dimensions of security indicators: availability, self-sufficiency, productivity and accessibility. The internal relationships among the three sectors and the main factors influencing WEF security were analysed by Spearman's rank correlation and radar graphs, respectively. The five countries in Central Asia (CA), which are experiencing WEF crises and facing great challenges in achieving their sustainable development goals (SDGs), were chosen as a case study in this paper. Our results showed that Kazakhstan attained the highest WEF security level, followed by Kyrgyzstan, Turkmenistan and Uzbekistan; Tajikistan exhibited the lowest security level from 2000 to 2014. Three types of internal relationships among the three sectors were identified: synergies, trade-offs and unclassified. The unclassified relationship type accounted for the largest share of 54% in CA, suggesting great potential for synergetic improvement among the three sectors. Approaches for improving the country WEF security based on our research are as follows: Kazakhstan should prioritize food allocation and supply, Kyrgyzstan and Tajikistan should increase energy and food production and raise the supply level and usage efficiency of water and food, Turkmenistan should increase the available water resources and food production and improve the supply level and usage efficiency of water and energy, and Uzbekistan should both increase the available amount and enhance the WEF management performance. [ABSTRACT FROM AUTHOR]

Rapid economic growth and social development in China have led to serious water pollution problems and water resource shortages, limiting the sustainable and coordinated development that could support both the socio-economy and water environment (WE). However, the spatial heterogeneity and evolutionary characteristics of the coordination between economic development (ED) and WE have not been adequately explored in China's provinces. In this study, we use the spatial global (local) autocorrelation and geographically weighted regression (GWR) model to explore the relationship between ED and WE subsystems and its influencing factors in China's provinces from 2010 to 2019. The main results are as follows, (a) The coupling coordination degree (CCD) between the two subsystems in southern China is higher than that of northern China. Transitional development areas have gradually spread to the middle of China, and there has been an increase trend in the number of moderate and high coordination provinces. (b) The ED-led (WE lags behind ED) type is mainly concentrated in central and eastern China, and the WE-led (ED lags behind WE) type is concentrated in the northeastern and western regions. The areas with synchronous development are relatively small in number and are mainly concentrated in east coastal China. (c) There is an obvious spatial dependence of the coordination between ED and WE from the perspective of global correlation, but this dependence is weakened with increasing geographical distance. The local mode of agglomeration shows a trend towards the evolution of high-high clustering in the eastern region. (d) The GWR analysis indicates that the factors of population density, energy consumption, fixed investment, and research and development (R&D) expenditure significantly influence the coordination between ED and WE. Fixed investment and R&D expenditure are mainly positive driving factors, while the impacts of population density and energy consumption vary among different regions as time evolves. Changes in driving force in a region can extend spatial effects to adjacent regions through the spatial transmission mechanism. Finally, we close the paper by recommending the different policy implications according to the GWR results. [ABSTRACT FROM AUTHOR]