Optimal allocation of physical water resources integrated with virtual water trade in water scarce regions: A case study for Beijing, China

Optimal water resource allocation considering virtual water trade in the Yellow River Basin

Water can be redistributed physically and virtually. We explored water allocation optimization to mitigate water stresses by constructing a physical-virtual dual water system and optimizing the 1987 Yellow River water allocation scheme. We calculated the virtual water volume, identified the virtual in-basin, out-of-basin, and export water volumes, and compared the total regional water demand (i.e., combined physical and virtual water volumes) with regional water planetary boundaries to optimize basin water allocation schemes. Virtual water accounted for > 90% of the total regional demands, whereas physical flows did not significantly impact them. Moreover, allocation quotas for Qinghai and Inner Mongolia should be reduced by 0.113 and 1.005 billion m3, respectively, for sustainability. Furthermore, improving the efficiency of water-intensive sectors and limiting virtual water outflows from heavy industry to out-of-basin sectors are vital to water intensification. Increased attention should be directed toward physical-virtual water demands than the current focus on supply-oriented water allocation.

China's dietary changes would increase agricultural blue and green water footprint

Agriculture accounts for 61 % of fresh water consumption in China. Although population and diet have a significant impact on water consumption, little is known about the reasons for and extent of their influence. Changes in the blue and green water footprint of 20 agricultural sectors in 31 Chinese provinces were estimated in 5 scenarios by applying the environmentally expanded multi-regional input-output model. The water footprint network is strongly interconnected, with over 50 % of the provinces characterized as net importers of the blue water footprint, 70 % of the total blue and green water footprint imports in developed provinces, and 65 % of the total blue and green water footprint exports in developing provinces, with the flow distribution driven and dominated by economically developed provinces. The findings also highlighted that the impact of population change on the water footprint is insignificant, contributing 0.51 % and 5.78 % to the reduction of the water footprint in 2030 and 2050, respectively. The impact of simultaneous changes in the population and dietary structure on the water footprint was higher than population changes and lower than dietary structure changes. The main force driving changes in the water footprint was changes in the dietary structure, which resulted in a two-fold effect on the water footprint. First, it has increased the blue and green water footprint by 33 % and 12 %, respectively, thus aggravating the coercive impact on water resources on the production side. Second, it has led to a change in the main contributing sectors for the blue and green water footprint from cereals to fruits, vegetables, and potatoes. Therefore, when the population is changing and optimizing its dietary structures, a greater focus must be placed on threats and pressures to water resources. This will result in better scientific management and more efficient use of water resources.

"Water-Carbon" redistribution caused by China's interprovincial grain transportation

Water resource and carbon emission involved in grain production in mainland China are redistributed among provinces as the grain was transported in recent years. This study first calculated the water consumption and carbon emission during the growth of grain crops based on the water-carbon footprint theory, and then used the social-equity method to calculate the inter-regional grain virtual water and virtual carbon flow. Finally, the regional and national trends in water saving and carbon emission reduction were calculated based on the spatial and temporal differences in grain planting among provinces. In terms of virtual water-carbon, from 2000 to 2017, the amount of the inter-provincial grain virtual water flow increased from 717.4 × 10⁸ m³ to 1472.6 × 10⁸ m³. Heilongjiang and Guangdong are the provinces with the largest amount of grain virtual water outflow (670.9 × 10⁸ m³) and inflow (402.8 × 10⁸ m³) in 2017, respectively. And the total inter-provincial grain virtual carbon flow increased from 2362.7 × 10⁴ t CO₂e to 12,680.6 × 10⁴ t CO₂e. Grain transport leads to water saving and carbon emission reduction, the amount of water saving increased from 25.6 × 10⁸ m³ to 77.0 × 10⁸ m³ and the carbon emission reduction increased from 2.4 × 10⁴ t CO₂e to 847.4 × 10⁴ t CO₂e from 2000 to 2017. Based on research results and from the perspective of socio-hydrology combined with water saving and carbon emission reduction, the regions could optimize the integration of water saving, carbon emission reduction, and sustainable development based on coordinating the grain planting structure according to their own climatic condition, soil and water resource condition, and socioeconomic condition.

Assessing the groundwater loss risk in Beijing based on ecosystem service supply and demand and the influencing factors

Incorporating ecosystem service supply and demand into ecological risk assessment can overcome the limitations of the traditional assessment framework. However, most previous studies are about theoretical discussions and applications of the assessment frameworks are very limited. In this study, we proposed an ecological risk assessment framework based on the supply and demand of ecosystem services and applied this framework to assess groundwater loss risk in Beijing. We calculated the water conservation service supply using the water balance equation and estimated the demand of the service using socioeconomic data from multiple sources. Moreover, the risk characterized by the risk probability of groundwater loss based on the budget of water conservation service was quantified. Furthermore, we delineated the spatial distribution characteristics of groundwater loss risk and analyzed natural and socio-economic factors affecting the risk using the geographically weighted regression (GWR). We found that the spatial distribution of water conservation supply and demand showed a mismatch. Moreover, high and very high groundwater loss risks were mainly distributed in the urban areas and on the cropland, and the very low risks were mainly located in the mountainous areas of Beijing. The average risk values in more than half of the administrative districts were >0.75 and parts of the new urban development areas displayed high groundwater loss risks. According to the GWR model, the impacts of the natural factors on the groundwater loss risk displayed larger spatial variations than those of the socioeconomic factors. Among the factors, population density exhibited a positive effect in most areas of Beijing and mainly affected the groundwater loss risk by influencing the water conservation service demand. Our study can provide a new perspective for ecological risk assessment in social-ecological systems and may provide scientific basis for the reduction of groundwater loss risk in Beijing.

Structural Characteristics and Evolutionary Drivers of Global Virtual Water Trade Networks: A Stochastic Actor-Oriented Model for 2000-2015

The globalization of trade has caused tremendous pressure on water resources globally, and a virtual water trade provides a new perspective on global freshwater sharing and water sustainability. No study has yet explored the structural characteristics and drivers of the evolution of global virtual water trade networks from a network structure evolution perspective. This paper aims to fill this critical gap by developing a research framework to explore how endogenous network structures and external factors have influenced the evolution of virtual water trade networks. We constructed virtual water trade networks for 62 countries worldwide from 2000 to 2015 and used an innovative combination of multi-regional input-output data and stochastic actor-oriented models for analytical purposes. Our results support the theoretical hypothesis of ecologically unequal exchange and trade drivers, arguing that virtual water flows from less developed countries to developed countries under global free trade and that unequal trade patterns lead to excessive consumption of virtual water in less developed countries. The results partially support the theoretical content of water endowment and traditional gravity models, finding that trade networks are expanding to farther and larger markets, confirming that national water scarcity levels do not impact the evolution of virtual water trade networks. Finally, we point out that meritocratic links, path dependence, reciprocity, and transmissive links have extreme explanatory power for the evolutionary development of virtual water networks.

The Life cycle Assessment Integrated with the Lexicographic Method for the Multi-Objective Optimization of Community-Based Rainwater Utilization

Community-based rainwater utilization (CB-RWU) has the advantage of easy maintenance and multiple benefits. However, its promotion proves to be a complicated task due to difficulties in quantifying and evaluating external benefits. This study integrated the life cycle assessment (LCA) with a multi-objective optimization model to optimize the relationship among all stages of CB-RWU, considering the trade-offs among the benefit-cost ratio, water-saving efficiency and environmental impact. The LCA results identified abiotic depletion potential for fossil fuels (ADPF) as the key impact indicators throughout the life cycle of CB-RWU. The optimal solution from the lexicographic method was 0.3098, 28.47% and 24.68 MJ for the benefit-cost ratio, water-saving efficiency and ADPF, respectively. Compared with the traditional optimization method, the lexicographic method improved the three object functions by 26%, 43% and 14%, respectively. The uncertainty of the environmental impact was the highest (C_V = 0.633) with variations in the floor area ratio, total runoff coefficient and reservoir volume. Changes in the total runoff coefficient were the main source of the uncertainty, which suggested that more attention should be paid to the area ratio of each underlying surface. In addition, economic support from the government is urgently required for the further promotion and development of CB-RWU.

Water footprint and virtual water trade analysis in water-rich basins: Case of the Chaohu Lake Basin in China

Water footprints and virtual water are widely used as essential tools for water use and conservation analysis of basins worldwide. Despite the importance of water-rich basins as the main force for water-saving, water use analysis has been mainly for water-scarce basins rather than water-rich basins in the existing literature. To fill the gap, in this paper, we investigate the water footprint and virtual water trade in a water-rich basin, namely the Chaohu Lake Basin in China, from 2007 to 2017 using input-output analysis. The results show that: (1) Water use efficiency in the Chaohu Lake Basin was significantly improved. The overall trend of the water intensity was declining, decreasing by 10.21 % in 2017 versus 2012; (2) The internal and external water footprints showed an upward trend, and the growth rate of total water footprint was 36.66 %; (3) The basin was a net virtual water exporter, but the net export flows of virtual water has decreased significantly. The virtual water net export flow decreased by 0.12 billion m³ in 2017 versus 2012; (4) Water resources in the basin were mainly used locally, and its supply to other provinces was minimal. Compared with some water-scarce basins such as the Heihe River Basin and Haihe River Basin, the Chaohu Lake Basin shows significant gaps in the virtual water export flow per capita and behaves differently in the proportion of virtual water transfer. Based on the above findings, we conclude with some guidance and implications for local governments and policymakers.

Dynamic simulation of industrial synergy optimisation pathways in Beijing-Tianjin-Hebei region driven by water environment improvements

China is promoting the coordinated development of the Beijing-Tianjin-Hebei region as a national strategy project; however, water scarcity and water quality problems will become a bottleneck restricting high-quality development. This study aimed to explore a feasible industrial synergy optimisation pathway to realise the collaborative development of economic growth and water environment improvement, combined with incentives for environmental efficiency improvement and reclaimed water utilisation. Research methods integrate input-output modelling, system dynamics, and multi-objective programming to construct a complex multi-region model. A dynamic simulation measure was adopted to simulate the economic and environmental impacts of different approaches that mix from 2020 to 2030 under water resource environment constraints. According to the simulation results, the annual economic growth rate of the entire region can exceed 6.1%, and the emission intensities of water pollutants decrease by more than 60.0%. In addition, traditional manufacturing industries that achieve cross-regional synergy can still release location advantages without negative environmental impacts. Furthermore, regional collaborative development optimises the allocation of water resources and alleviates water stress. Moreover, the pollutant emission reduction effect of source control in Hebei was more effective than in other cities. Finally, reclaimed water, as the end treatment measure, has the largest marginal effect on improving the trade-off between economic and environmental improvement in the long run. This study provides a new approach for multi-regional industrial synergy development and optimal allocation of resources and contributes to the high-quality development of the watershed.

Pollution exacerbates interregional flows of virtual scarce water driven by energy demand in China

Existing studies on the virtual scarce water flows within the water-energy context focus on water quantity while largely ignoring water quality. This study improves the quantification method of scarce water uses by considering both blue water (representing water quantity) and grey water (indicating water quality). Based on a scarce-water extended multi-regional input-output model, we investigate the virtual scarce water flows driven by energy demand across 31 Chinese regions in 2012 and 2017. The results show that considering water quality provides new insights into the patterns of interregional flows of virtual scarce water driven by energy demand. The virtual integrated scarce water (VISW) flows, which consider both water quantity and quality, are 5 times the volume of virtual quantity-based scarce water (VQSW) flows. Moreover, certain regions (e.g., Hebei) are recognized as net VISW exporters, but are net importers in terms of VQSW. There are significant differences in the critical interregional pairs identified based on net VISW flows (e.g., Shandong-Zhejiang, and Shandong-Guangdong) and net VQSW flows (e.g., Heilongjiang-Guangdong, and Liaoning-Shaanxi). To reduce water scarcity based on the combined effect of both quantity and quality, the critical VISW interregional pairs should enhance cooperation through compensation payments and interregional technology transfer. This study highlights the importance of water quality in the assessment of virtual scarce water uses. Employing virtual scarce water as a policy tool to mitigate water scarcity might fail without the consideration of water quality.

The Temporal Evolution of Physical Water Consumption and Virtual Water Flow in Beijing, China

With the rapid development of the socio-economic system and the close connection of inter-regional trade, the physical water consumption in production and the virtual water flow associated with inter-regional trade are both have a significant impact on local water systems, especially in megacities. Beijing is the political, economic and cultural center of China, which is a megacity that has severe water scarcity. To evaluate the status-quo of local water consumption and propose the countermeasures, this study quantitatively analyzed the evolution trend of physical water consumption and the virtual water flow in Beijing. The results show that the total physical water consumption in Beijing decreased from 2.43 billion m3 (2002) to 1.98 billion m3 (2017), while the net virtual water input increased from 1.76 billion m3 (2002) to 3.09 billion m3 (2017), which was mainly embedded in agricultural and industrial products. This study also reveals the equal importance of physical water and virtual water in ensuring the regional water security and sustainable economic development. In view of poor water resource endowment, Beijing should conduct the coupled management of physical water and virtual water to alleviate the local water shortage, i.e., to receive more virtual water embedded in agricultural and industrial products, and allocate the limited local water resources to domestic use and high-benefit sectors.

Analysis on Management Policies on Water Quantity Conflict in Transboundary Rivers Embedded with Virtual Water—Using Ili River as the Case

Current studies neglect how virtual water transfer (VWT) between countries within a drainage basin affects water stress and then yields an invisible effect on the water quantity conflict in transboundary rivers, which would further make management policies on water quantity conflict less fair and reasonable. Therefore, this study first constructs the Inequality Index of VWT and water stress index (WSI) to assess water stress. Next, different types are set according to the Inequality Index and WSI to analyze management policies, with Ili River as the case. Results show: (1) Within the study period, from 1996, the Inequality Index of VWT between China and Kazakhstan stayed at 0.368 (0.368 < 0.5), indicating a relatively high inequality of VWT between the two countries—China at a disadvantage, while Kazakhstan having the upper hand. (2) According to the remotely sensed data, WSI in the riparian zones of the Ili River rose from 0.288 to 0421 in China, and 0214 to 0.402 in Kazakhstan, showing intermediate scarcity. (3) China and Kazakhstan both fall into Type 2, and Kazakhstan has the advantageous position. Therefore, while allocating the water resources of the Ili River, Kazakhstan should lower its expectation and proactively ask to exchange benefits in other aspects to reverse the outward transfer of its physical water. In addition, the two countries should find suitable ways to go about water rights trading to reduce the possibility of potential water quantity conflict.

Invisible Effect of Virtual Water Transfer on Water Quantity Conflict in Transboundary Rivers—Taking Ili River as a Case

Water stress in countries within a drainage basin exacerbates the water quantity conflict in transboundary rivers. However, few studies considered the invisible effect of virtual water transfer on water quantity conflict by intensifying water stress. Therefore, this study, with Ili River as the case, collects data on Virtual Water Trade (VWT) from 1990 to 2015, uses water stress index (WSI) to assess water stress values under two scenarios (with or without virtual water transfer), and takes Grey Verhulst Model to predict two scenarios water stress values respectively. Next, based on the Levenberg—Marquardt (LM) Algorithm, this study compares the water quantity conflict intensity of the two scenarios, and further explores the invisible effect of virtual water transfer on the conflicts among transboundary rivers. Results show: (1) During the study period (1990–2015), water stress in China and Kazakhstan along the banks of Ili River increased in general. (2) China was basically a net exporter of virtual water during 1990–1995, and Kazakhstan became a net exporter after 1995. (3) During 2020–2025, water conflict value of Ili River without virtual water transfer is 0.458, while the value rises to 0.622 with virtual water transfer, indicating that virtual water transfer between China and Kazakhstan has an invisible enhancement on the water quantity conflict of Ili River. (4) The intensified water quantity conflict is mainly caused by the more and more serious water stress in Kazakhstan. On such basis, it is more urgent for Kazakhstan to restructure its economy and trade.

Unconventional water resources: Global opportunities and challenges

Water is of central importance for reaching the Sustainable Development Goals (SDGs) of the United Nations. With predictions of dire global water scarcity, attention is turning to resources that are considered to be unconventional, and hence called Unconventional Water Resources (UWRs). These are considered as supplementary water resources that need specialized processes to be used as water supply. The literature encompasses a vast number of studies on various UWRs and their usefulness in certain environmental and/or socio-economic contexts. However, a recent, all-encompassing article that brings the collective knowledge on UWRs together is missing. Considering the increasing importance of UWRs in the global push for water security, the current study intends to offer a nuanced understanding of the existing research on UWRs by summarizing the key concepts in the literature. The number of articles published on UWRs have increased significantly over time, particularly in the past ten years. And while most publications were authored from researchers based in the USA or China, other countries such as India, Iran, Australia, and Spain have also featured prominently. Here, twelve general types of UWRs were used to assess their global distribution, showing that climatic conditions are the main driver for the application of certain UWRs. For example, the use of iceberg water obviously necessitates access to icebergs, which are taken largely from arctic regions. Overall, the literature review demonstrated that, even though UWRs provide promising possibilities for overcoming water scarcity, current knowledge is patchy and points towards UWRs being, for the most part, limited in scope and applicability due to geographic, climatic, economic, and political constraints. Future studies focusing on improved documentation and demonstration of the quantitative and socio-economic potential of various UWRs could help in strengthening the case for some, if not all, UWRs as avenues for the sustainable provision of water.

A scenario analysis-based optimal management of water resources supply and demand balance: A case study of Chengdu, China

Water resources scarcity has threatened the coordinative development of demographics, society and economy. As a typical rapidly urbanizing area and an emerging megacity in China, Chengdu is confronting the pressure of inadequate water supply. The present study divides the macroeconomic factors that affect the water resource supply and demand balance into six major subsystems: water resources supply, water demand, water drainage, population, ecological environment and economy. The combining variable interaction description and predictive simulation models are applied to simulate the water supply and demand ratio (S:D) from 2005 to 2035. Further, this study designs different development scenarios to simulate the change of S:D ratios by altering the parameter values of driving factors. The results show that: (1) the S:D ratio will decline if the current development scenario continues, implying the serious water resources shortage and the severe water supply-demand conflict in Chengdu; (2) socio-economic water demand and wastewater/rainwater reuse are the key driving parameters of S:D ratio, especially the water consumption per ten thousand yuan of industrial value-added; (3) the S:D ratio will increase from 0.92 in the current baseline scenario to 1.06 in the integrated optimization scenario in 2025, and the long-term planning brings 2035 from 0.71 to 1.03, with the proportion of unconventional water supply rise to 38% and 61%, respectively. This study can provide a decision-making tool for policy-makers to explore plausible policy scenarios necessary for bridging the gap between the water supply and demand in megacities.

Optimal allocation and transaction of waste load permits for transboundary basin: A Bi-level programming approach based on node-arc

Inadequate water quality exacerbates global water resources scarcity. Hence, water quality of the river basin is increasingly perceived as a global obstacle to sustainable development because of the limited water carrying capacity. Efficient waste load permits (WLPs) allocation plays a critical role in enhancing water quality by controlling the emission cap. Considering transboundary water pollution and transaction among regions, a bi-level objective model is proposed to analyze the WLPs allocation based on the node-arc method. Motivated by alleviating regional development differences, the watershed management committee concentrates on equitable distribution of WLPs to regions. Furthermore, regional authorities focus on how to guarantee the maximum economic development and balance the WLPs emissions from the municipal, industrial, and agricultural sectors. Practicality and efficiency of the constructed model is demonstrated by applying it to Tuojiang River Basin. Through the analysis of the results, three management recommendations are proposed for Tuojiang River: strengthening the prevention of agricultural non-point source pollution, sticking to the cooperation between upstream and downstream regions, and speeding up the construction of sewage environmental tax system. The results illustrate that as the proposed method can control the total amount of sewage, it could provide decision-making references for the amelioration of water environment.

Multi-objective optimization of the coastal groundwater abstraction for striking the balance among conflicts of resource-environment-economy in Longkou City, China

Rational coastal groundwater planning is of great significance to freshwater supply for sustainable social-economic development, and to environmental protection in case of seawater intrusion (SI). Quantifying the relation among groundwater quality, quantity, and the related social-economic benefits in a coastal region with intense spatio-temporal variation in groundwater abstraction is helpful to the restoration of the coastal aquifer, and the practical policymaking. However, due to the comprehensive reality involving interdisciplinary principles, it is usually difficult to integrate all the main attributes of groundwater resources into a mono-policymaking process, which might lead to biased decisions, producing a series of adverse impacts on the environment and the social economy. This study thereby develops a combined simulation-optimization model (S-O model) in the coastal part of Longkou City, China, for striking the balance among the three main attributes of groundwater, i.e., the groundwater quantity, groundwater quality or its environmental function, and its related economic yield involving the agricultural and industrial sectors. It is seen that the industrial sector contributed over 80% of the economic yield by consuming over 10% of the total groundwater resource, and the massive agricultural use of groundwater was mainly responsible for the SI. The results of the multi-objective optimization provided practical alternative schemes for groundwater abstraction in terms of maximizing economic yield and minimizing SI. Moreover, the decision discrepancy caused by partial management only considering the groundwater quantity and quality would lower the water use efficiency, and then cause unacceptable economic losses for the enterprises and the government. Our research highlights that the interdisciplinary management of groundwater resources based on the S-O model could significantly improve practicability in groundwater policymaking, and provides a typical reference for the other developing regions facing difficulty in groundwater management during coastal urban planning and economic transformation.

Development of Method for Assessing Water Footprint Sustainability

Large scale production of water-intensive industrial products can intensify water scarcity, resulting in potential unsustainable water use at local and regional scales. This study proposes a methodological framework for assessing the WF sustainability of multiple interdependent products in a system, and one of China’s four major large modern coal chemical industry bases is used as a case study. A Mixed-Unit Input-Output (MUIO) model was applied to calculate the blue water footprint (WF) for 19 major coal-based energy and chemicals in the study area, based on which the WF sustainability of production of the products were assessed using different indicators. Technical coefficient matrix and direct water consumption vector of the products were constructed based a database that were built by field research in the study area. Accounting result indicates that the blue WF of the coal-based products range from 2.5 × 10−4 m3/kWh for coal-fired power to 55.25 m3/t for Polytetrahydrofuran. The sustainability assessment reveals that the blue WF of all products produced in the study area are sustainable at both product and regional levels, while over half of them have reached the advanced level. However, the blue WF of a few products with large production capacities has just crossed the sustainable thresholds, posing potential threat to the local environment. This paper concludes with a discussion on the choice of blue WF accounting approach, methods to promote WF sustainability of coal-based products, and suggestions for the WF management in general.

Sustainable conjunctive water management model for alleviating water shortage

Water shortage poses a great challenge to the health of population and environment and impedes socio-economic development. Therefore, a comprehensive model is necessary to promote the adaptation of the whole socio-economic system to limited water resources. To achieve it, a sustainable conjunctive water management model (SCWM) was developed. In SCWM, direct (physical) and indirect (virtual or embodied) water consumptions of multiple water resources in future scenarios are projected, and the sustainable performances of various water-saving scenarios are quantified from the perspectives of water resources, economy, and ecosystem under water capping policy. A case study of Shaanxi, a typical water shortage province in central-eastern China, is conducted aimed at conquering the irrational use of surface- and ground-water subjected to the constraint of future total water use quota. Key findings contain optimal possibility of adapting water shortage via saving water through increasing industrial water efficiency to 11.12 m³/10,000 CNY and reducing 40% of agricultural final demand (Summation of direct and indirect water savings of the two scenarios are 41.57 × 10⁸ m³ and 20.27 × 10⁸ m³, respectively.) and nonsynergistic effects of simultaneous decreasing final demand of multiple sectors on water consumption intensity (WCI) of total (all kinds of water) water, surface- and ground-water. To devise effective policies for conjunctive management of surface- and ground-water, positive utility, economic structure and water productivity should be heeded, and proposals emphasize trade-offs between surface water saving and groundwater conservation, water metabolic and socio-economic systems sustainability and negative interaction of multiple sectors on economy and WCI should be framed. The innovation of this study is the development of SCWM, which can provide sustainable solution for future multiple-source water saving management measures thoroughly concerning direct and indirect water and sectorial interactions. The model not only brings insights to Shaanxi's water management but also can be used for other similar arid area.

Multi-Objective Optimal Allocation of River Basin Water Resources under Full Probability Scenarios Considering Wet-Dry Encounters: A Case Study of Yellow River Basin

Wet-dry encounters between basins and regions have an important impact on the allocation of water resources. This study proposes a multi-objective allocation model for basin water resources under full probability scenarios considering wet-dry encounters (FPS-MOWAM) to solve the problem of basin water resource allocation. In the FPS-MOWAM model, the sub-regions were merged by precipitation correlation analysis. Next, the joint probability distribution of basin runoff and region precipitation was constructed using copula functions. The possible wet-dry encounter scenarios and their probabilities were then acquired. Finally, the multi-objective allocation model of water resources was constructed using the full probability scenario for wet-dry encounters in each region. The FPS-MOWAM is calculated by the NSGA-II algorithm and the optimal water resource allocation scheme was selected using the fuzzy comprehensive evaluation method. Using the Yellow River Basin as an example, the following conclusions were obtained: (1) the Yellow River Basin can be divided into four sub-regions based on precipitation correlations: Qh-Sc (Qinghai, Sichuan), Sg-Nx-Nmg (Gansu, Ningxia, Inner Mongolia), Sxq-Sxj (Shaanxi, Shanxi), and Hn-Sd (Henan, Shandong), (2) the inconsistencies in synchronous-asynchronous encounter probabilities in the Yellow River Basin were significant (the asynchronous probabilities were 0.763), whereas the asynchronous probabilities among the four regions were 0.632, 0.932, and 0.763 under the high, medium, and low flow conditions in the Yellow River Basin respectively, and (3) the allocation of water resources tends to increase with time, allocating the most during dry years. In 2035, the expected economic benefits are between 11,982.7 billion CNY and 12,499.6 billion CNY, while the expected water shortage rate is between 2.02% and 3.43%. In 2050, the expected economic benefits are between 21,291.4 billion CNY and 21,781.3 billion CNY, while the expected water shortage rate is between 1.28% and 6.05%.

Optimal virtual water flows for improved food security in water-scarce countries

The worsening water scarcity has imposed a significant stress on food production in many parts of the world. This stress becomes more critical when countries seek self-sufficiency. A literature review shows that food self-sufficiency has not been assessed as the main factor in determining the optimal cultivation patterns. However, food self-sufficiency is one of the main policies of these countries and requires the most attention and concentration. Previous works have focused on the virtual water trade to meet regional food demand and to calculate trade flows. The potential of the trade network can be exploited to improve the cropping pattern to ensure food and water security. To this end, and based on the research gaps mentioned, this study develops a method to link intra-country trade networks, food security, and total water footprints (WFs) to improve food security. The method is applied in Iran, a water-scarce country. The study shows that 781 × 10⁶ m³ of water could be saved by creating a trade network. Results of the balanced trade network are input to a multi-objective optimization model to improve cropping patterns based on the objectives of achieving food security and preventing water crises. The method provides 400 management scenarios to improve cropping patterns considering 51 main crops in Iran. Results show a range of improvements in food security (19–45%) and a decrease in WFs (2–3%). The selected scenario for Iran would reduce the blue water footprint by 1207 × 10⁶ m³, and reduce the cropland area by 19 × 10³ ha. This methodology allows decision makers to develop policies that achieve food security under limited water resources in arid and semi-arid regions.

Ecological network analysis of an urban water metabolic system: Integrated metabolic processes of physical and virtual water

The contradiction between social economy and water environment has become increasingly prominent, and the analysis of urban water metabolism system (UWMS) represents a problem-solving approach from the perspective of the entire flow process. However, a comprehensive UWMS model that considers both physical and virtual water flows is currently lacking. This paper presents an innovative application of an ecological network model of the UWMS-integrated metabolic process of physical and virtual water in Xining during the 2002-2018 period. By analysing and screening the metabolic characteristics, metabolic structure and metabolic relationships, the sustainability of the UWMS is evaluated in depth, and the main causes and critical compartments of the unhealthy metabolic process are identified. The findings show that the UWMS in Xining maintains a moderate level of robustness (the average R = 0.48) with limited metabolic efficiency. Since 2012, the water management policies in Xining have been significantly strengthened, contributing to a slight increase in robustness by improving the water use efficiency and metabolic structure. The integrated metabolic process is unhealthy because the metabolic structure is not reasonable, and the systematic metabolic relationship tends to be antagonistic due to the network mutualism index dropping to 1.0 during 2016-2018. We conclude that efficient irrigation management, more infrastructure projects for the sewer network, wastewater treatment and recycling could provide effective support to enhance the coordinate development of the social economy and water environment in Xining.

Global environmental inequality: Evidence from embodied land and virtual water trade

The trade-off between economic growth and environmental conservation is the focus of national environmental management. Previous studies have proved that global trade can bring both economic benefits and environmental costs to all countries. However, for different countries, it is not clear whether the environmental costs match their economic benefits in global trade. Also, whether the global trade exacerbates or mitigates the uneven distribution of natural resources among countries need to be further investigated. This study aims to fill these research gaps by providing evidence of global environmental inequality from land and water perspective, thus inspire new thinking on the optimization of global trade patterns. We construct an environmental inequality index based on the world Multi-Regional Input-Output (MRIO) model, and perform a case study for land and water. Results show that most of countries with low per capita land resources are net importers of embodied land, while many countries with extreme water shortages are net exporters of virtual water, such as India, Pakistan, Iran and Egypt, indicating that the global trade encourages the optimal distribution of land resources but exacerbates the uneven distribution of water resources. The environmental cost of developed countries is much lower than that of developing countries compared to their economic gains from global trade, and the inequality of virtual water trade is higher than that of embodied land trade. High-income countries mainly export high value-added products with low environmental costs, while developing countries are just the opposite. We suggest that due to the lack of a unified global natural resource market, resource tax may be an effective means to reduce global environmental inequality and resource mismatch, and policies aimed at reducing environmental inequality can help achieve coordinated management of land and water resources.

A dual-randomness bi-level interval multi-objective programming model for regional water resources management

In this research, a dual-randomness bi-level interval multi-objective programming (DR-BIMP) model was developed for supporting water resources management among multiple water sectors under complexities and uncertainties. Techniques of bi-level multi-objective programming (BMOP), double-sided stochastic chance-constrained programming (DSCCP), and interval parameter programming (IPP) were incorporated into an integrated modeling framework to achieve comprehensive consideration of the complexities and uncertainties of water resources management systems. The DR-BIMP model can not only effectively deal with the interactive effects between multiple decision-makers in complex water management systems through the bi-level hierarchical strategies, but also can characterize the multiple uncertainties information expressed as interval format and probability density functions. It could thus improve upon the existing bi-level multi-objective programming through addressing discrete interval parameters and dual-randomness problems in optimization processes simultaneously. Then, the developed model was applied to a real-world case to optimally allocate water resources among three different water sectors in five sub-regions in the Dongjiang River basin, south China. The results of the model include determining values, interval values, and stochastic distribution information, which can assist bi-level decision-makers to plan future resources effectively to some extent. After comparing the variations of results, it is found that an increasing probability level can lead to higher system benefits, which is increased from [20,786.00, 26,425.92] × 10⁸ CNY to [22,290.84, 27,492.57] × 10⁸ CNY, while the Gini value is reduced from [0.365, 0.446] to [0.345, 0.405]. A set of increased probability levels gives rise to the lower-level objectives. Furthermore, the advantages of the DR-BIMP model were highlighted by comparing with the other models originated from the developed model. The comparison results indicated that the DR-BIMP model was a valuable tool for generating a range of decision alternatives and thus assists the bi-level decision-makers to identify the desired water resources allocation schemes under multiple scenarios.

Life cycle water footprint comparison of biomass-to-hydrogen and coal-to-hydrogen processes

Water is essential for the industrial production of hydrogen. This study investigates the production of hydrogen from biomass and coal. To date, there are few studies focusing on the water footprint of biomass-to-hydrogen and coal-to-hydrogen processes. This research conducted a life cycle water use analysis on wheat straw biomass and coal to hydrogen via pyrolysis gasification processes. The results show that the water consumption of the entire biomass-to-hydrogen process was 76.77 L/MJ, of which biomass cultivation was the dominant contributor (99%). Conversely, the water consumption of the coal-to-hydrogen process was only 1.06 L/MJ, wherein the coal production stage accounted for only 4.15% for the total water consumption, which is far lower than that of the biomass-to-hydrogen process. The hydrogen production stage of biomass hydrogen production accounted for 76% of the total water consumption when excluding the water consumption of straw growth, whereas that of the coal hydrogen production stage was 96%. This research provides the associated water consumption, within a specified boundary, of both hydrogen production processes, and the influence of major factors on total water consumption was demonstrated using sensitivity analysis.

Crop Production Allocations for Saving Water and Improving Calorie Supply in China

The limited available water resources and competition among different water use sectors have become the main constraints of food security and sustainability. Faced with the inability to expand the area of cultivated land due to urbanization and population growth, one of the biggest challenges and risks for developing countries is to ensure the supply of food quantity and quality under extremely limited water resources. To achieve water-saving and improve calorie supply by adjusting crop production allocations, three objectives—of minimum blue water footprint, maximum calorie production, and each crop production no less than the reference level of nine main crops in China—were achieved using a non-dominated sorting genetic algorithm II. The results display that compared with the reference year, model Maize+ (maize production increased) had significant blue water saving (~32%), the blue water footprint of crop production in all provinces reduced, and its calorie production increased by 4%. This solution is not realistic for China because wheat and rice production need to be reduced by 82 and 80%, respectively. However, model Citrus– (citrus production decreased) reduced the blue water footprint of crop production (~16%), and increased calorie production (~12%). Compared with other solutions, it is a sustainable crop production structure that is easier to realize because it is better at meeting the production of each crop. Therefore, China can appropriately increase the planting area of maize and reduce the planting of citrus and other crops that consume more blue water and produce fewer calories to ensure the security and sustainability of food supplies. However, the improvement of water saving-technology, rationalization of agricultural water resources management, crop production allocations mentioned in this study, and other efforts are necessary to achieve this goal.

Spatio-temporal characteristics of adaptability between crop water requirements for summer maize and rainfall in Henan Province, China

It is very important to master the rainfall utilization efficiency and spatial-temporal distribution characteristics in order to improve the agricultural water resource utilization efficiency. In this study, an adaptability index (AI) was constructed to reflect the relationship between rainfall and crop water demand. Spatial analysis and clustering analysis were used to study the spatial distribution characteristics and evolution rules of the adaptability between water demand and rainfall in the growing period of summer maize in Henan Province of China. The results showed that there were significant spatial differences in the adaptability of different regions, and such differences change with time, indicating that AI has certain uncertainties in the region and growth season. In general, the AI of the whole growth period of summer maize is mainly determined by the AI of tasseling period-milky period, while the multi-year change rate of AI is mainly determined by the emergence period-jointing period, tasseling period-milky period, and milky period-maturity period The adaptability of summer maize to rainfall in the study area can be divided into three categories, among which the one with increased adaptability occupies the main part, and the one with sharply decreased adaptability were also distributed in the study area. The above studies indicate that it is important to pay attention to the adaptability of rainfall to agricultural water management. The complexity division of crop water demand by rainfall adaptability index can guide the establishment of reasonable and accurate irrigation system.

Globalized energy-water nexus through international trade: The dominant role of non-energy commodities for worldwide energy-related water use

The increasing energy demand in future will inevitably escalate pressures on water resources, as energy production needs huge amounts of water inputs. Globalization has resulted in the geographic separation between the source of water inputs for energy production and the sink of its final consumption, making it crucial to factor global supply chain effect into water-energy nexus management. Therefore, this paper investigates water use for energy from source of exploitation to sink of final consumption along global supply chains based on embodiment accounting method. In total, the energy-related water use embodied in international trade is in magnitude about 80% of global total energy-related water use in 2011. It should be noted that non-energy commodities contribute more than four fifths of energy-related water use embodied in international trade and global final consumption. China serves the largest exporter of energy-related water use while EU28 is the biggest receiver. From a perspective of global supply chains, two thirds of USA direct energy-related water use sinks into final consumption from rest of the world, and over a quarter of that embodied in Mainland China's final consumption is from USA, showing the tight relation between them on global supply chains. Findings highlight the urgent need to consider international trade (i.e., energy and non-energy commodity trade) and global supply chain effects for water-energy nexus policy-making to ensure the sustainable water supply for energy development.

Investigating and optimizing the water footprint in a typical coal energy and chemical base of China

The water scarcity in China's coal bases is intensifying due to rapid development of modern coal chemical industry and inefficient water utilization. Previous studies on industrial water optimization were predominantly focused on direct water, overlooking the associated indirect water consumptions throughout supply chains. In this study, a water footprint (WF)-based allocation optimization framework is developed to obtain optimal solutions for water resources utilization constrained by quantity of water supply and coal chemical production related limiting factors. The framework comprises a novel WF accounting model especially used for the coal-to-chemical industry and a water allocation optimization model that integrates direct and indirect water consumptions. A typical major large-scale coal base in China was chosen as the study area. Results showed that the cradle-to-gate WF of the various coal-based products ranged from 2.01 m³/t to 70.85 m³/t, in which the internal operational and supply-chain blue WFs were the dominant contributors. Statistical analysis suggested that the volumetric WF of the coal-based products was strongly correlated with both market price and production stage while the variation of WF increased as products were further processed. Optimization result indicated that the maximized economic income of the products under current scenario was 66.23 billion CNY/year in the study area, whereas the overlapping of limited water resources and the insufficiency of downstream production capacity restricted the economic performance by over 20%. In addition, sensitivity analysis was conducted and the results showed that, in order to improve the overall economic income, deployment of more advanced technologies for saving water should be prioritized over that for saving feedstock, while conservation of power was the least preferable.

Water stress assessment integrated with virtual water trade and physical transfer water: A case study of Beijing, China

With the increase in population and economic development, urban water demand has increased significantly over the past decades, and physical transfer water (i.e., freshwater transported from water source regions to water intake regions through channels or pipelines) and virtual water (i.e., freshwater used in the production of goods and services along their supply chains, abbreviated as VW) have gradually become viable water sources for many cities to relieve water stress. This study used Beijing as the research object and systematically analyzed the impact of physical transfer water, VW, and local water on urban water stress from 2000 to 2016. The results show that VW inflow related to food trade has increased from 3.55 billion m³ in 2000 to 16.76 billion m³ in 2016, and that energy's VW inflow increased from 52.76 million m³ to 137.47 million m³ over the same period. Before 2011, Beijing's water demand was largely met by local water resources; however, after 2011, external water resources (including physical transfer water and VW) accounted for majority of the city's water demand, and VW's contribution increased from 47% in 2011 to 53% in 2016. Although Beijing has significantly reduced local water use in favor of external sources, its water stress index in 2016 remained considerable, far exceeding the upper limit of available water. This study also proposes some measures to ensure Beijing's water security based on the sustainability of external water supply.

The Impact of Virtual Water on Sustainable Development in Gansu Province

The concept of virtual water, as a new approach for addressing water shortage and safety issues, can be applied to support sustainable development in water-scarce regions. Using the input-output method, the direct and the complete water use coefficients of industries categorized as primary, secondary, or tertiary, and the spatial flow patterns of the inter-provincial trade in the Gansu province region of China, were explored. The results show that in 2007, 2010, and 2012 the direct and complete water use coefficients of the primary industries were the greatest among the three industry categories, with direct water use coefficients of 1545.58, 882.28, and 762.16, respectively, and complete water use coefficients of 1692.22, 1005.38, and 873.44, respectively; whereas, the direct and complete water use coefficient values of the tertiary industry category were the lowest, with direct water use coefficients of 16.65, 7.74, and 66.89 for 2007, 2010, and 2012, respectively, and complete water use coefficients of 65.46, 66.89, and 72.81 for 2007, 2010, and 2012, respectively. In addition, study results suggest that the volume of virtual water supplied to Gasnu province’s local industries has decreased annually, while virtual water exports from the province have increased annually, with the primary industry accounting for 95% of virtual water output. Overall, the virtual water of Gansu province in 2010 showed a net output trend, with a total output of 0.506 billion m3, while in 2007 and 2012 it showed a net input trend with a total input of 0.104 and 1.235 billion m3, respectively. Beijing, Shanghai, Guangdong, Ningxia and other water-scarce areas were the main input, or import source for Gansu’s virtual water; during the years studied, these provinces imported more than 50 million m3 individually. Based on these results, it is clear that under the current structure, virtual water is mainly exported to the well-developed coastal areas and their adjacent provinces or other water-abundant regions. Therefore, Gansu province should (1) adjust the industrial structure and develop water-saving and high-tech industries; (2) adjust the current trade pattern to reduce virtual water output while increasing its input to achieve balanced economic development and water resource security.

Estimation of regional irrigation water requirements and water balance in Xinjiang, China during 1995-2017

Estimating water requirements and water balance for irrigated agricultural areas are important and will facilitate the efficient allocation of water resources for agriculture while minimizing the impact on natural ecosystems in arid regions. Based on the Penman-Monteith formula and GIS technology, the irrigation water requirements (IWR) of three main crops (cotton, corn and wheat) during the growing season were estimated and their spatio-temporal changes over the past 23 years (1995–2017) were analyzed in Xinjiang province, China. Our results indicated a dramatic increase in IWR from 14.12 billion m³ in 1995 to 38.99 billion m³ in 2017 due to the rapid cropland expansion of approximately 2.58 × 10⁴ km² in this period. Monthly IWR usually peaked in summer from May to July and varied in different basins. From the perspective of crops, cotton was identified to have consumed the largest amount of water, reaching 26.39 billion m³ in 2017, accounting for 67.68% of total water consumption. Spatially, the fastest increasing rate of IWR was Tarim Basin, which was attributable to the increase in water requirement of cotton. By comparing IWR and actual irrigation of Xinjiang in 2014, the amount of water scarcity had reached −15.01 billion m³ (−9.80 billion m³ in Tarim Basin and −6.58 billion m³ in Junggar Basin). The planting areas of three main crops (wheat, corn and cotton) were more sensitive to IWR than rising temperature indicated by our model. This study is of great significance for the scientific allocation of water resources in the irrigated areas of the different prefectures of Xinjiang.

The Cognitive Framework of the Interaction between the Physical and Virtual Water and the Strategies for Sustainable Coupling Management

In the context of a changing environment and economic globalization, the evolution of regional hydrology and water resources systems has undergone profound changes. It is not enough to rely on traditional physical water resources planning, scheduling, and regulation methods to solve problems such as water shortages and imbalances in the water cycle associated with rapid economic development. The theory of virtual water expands the cognitive scope of hydrology and water resources and enriches the solutions to water problems. However, the academic community has not yet reached a consensus on how to build a unified framework of the virtual water theory and traditional hydrology and water resources recognition system, how to understand the new laws of water resources evolution in the natural–economic continuous system, and then how to realize efficient and sustainable usage of water resources through physical water–virtual water integrated management. This paper proposes a basic cognitive model of coupling of physical water–virtual water and discusses the evolution of hydrology and water resources in a natural–economic system, presenting the laws of the coupled flow of physical water–virtual water in natural systems and human economic systems. A quantitative expression equation is proposed for the flow process, and a basic theoretical framework for the coupled flow of physical water–virtual water is preliminarily constructed. At the end of the paper, the basic strategy for the regulation of a physical water–virtual water integrated management system is proposed, which provides a new perspective for the efficient and sustainable use of global water resources in a changing environment.

Explaining virtual water trade: A spatial-temporal analysis of the comparative advantage of land, labor and water in China

The well-known "virtual water hypothesis" states that water-deficient regions/countries could alleviate water stress through importing water-intensive products from water-abundant regions/countries. Although observed trading patterns do often not support this hypothesis, there is a lack of research to explore the reasons why trade patterns often do not support the intuitive virtual water hypothesis. To fill this important gap, we introduce comparative advantage theory in a quantitative way to track the driving forces of net virtual water export based on the spatial-temporal distribution of resource productivity and opportunity costs of land, labor and water use in agricultural and non-agricultural sectors across Chinese provinces between 1995 and 2015. The results show that regional differences in land productivity between agricultural and non-agricultural sectors are the main forces determining the pattern of virtual water flows across major regions, and other resources such as labor and water have played only a limited role. Our study shows that the current market forces reflect the scarcity of land resources, but does not reflect the water scarcity in the context of interregional trade in China. Our findings suggest that the ongoing efforts to increase land productivity of agriculture in the southern regions would contribute to reducing water scarcity in the North and Northeast China Plain.

Transfer of virtual water embodied in food: A new perspective

Food and water are inextricably linked. With the increase of water consumption in irrigation and food growth, water shortage has become an urgent issue. Irrational cross-regional transfer of water embodied in food exacerbates water scarcity and restrict China's sustainable development. Given that, a Virtual Water-Food Nexus Model is developed to quantify the inter-provincial transfer of water embodied in food and to identify the complicated interactions between different provinces. In detail, Environmental Input-Output Analysis is applied to quantitatively estimate the inter-provincial water transfer embodied in food trades. Based on the network constructed by interrelated nature of nexus, the mutual interactions, control situation, and the dominant and weak pathways are examined through the combination of Ecological Network Analysis and Principal Component Analysis. Two new indictors water consumption intensity and water supply capacity are first performed to measure the role of each province from the supply and consume side respectively. It is revealed that interregional food transactions failed to realize water resources dispatching management. Many water-deficient regions suffered from massive virtual water losses through food exports, but water-rich areas still import large quantities of food containing virtual water. Results show that exploitation and competition dominate the ecological relationships between provinces. Agricultural GDP ratio is the indicator which most affect water consumption intensity and water supply capacity. Network-based research contributes more insights into the recognition of water management responsibilities across provinces and municipalities. These findings will provide a scientific support to adjust unreasonable allocation of water resources in China in an attempt to addressing the contradiction between food demand and water shortages.

Assessment of Water Resources Sustainability in Mainland China in Terms of Water Intensity and Efficiency

Investigation into water resources sustainability (WRS) is vital for a regional sustainable development strategy. This paper aimed to quantitatively evaluate the WRS in mainland China using a three-layer indicator system. Three important factors significantly affecting WRS are: water resources quantity (WRQ), water intensity (WI) and water efficiency (WE). Assessment of the three indicators was carried out in 356 cities where each indicator was graded from "very low" to "very high" according to the value magnitude. China was then classified into four zones to differentiate regional variations of the impact of water intensity and efficiency on sustainability. Results showed that 34% of the areas had "medium" to "high" WI indicator values and 58% of the areas had "low" to "very low" WE indicator values. The indicator values of WI were ordered as Zone I > Zone II > Zone III > Zone IV; whereas the WRS were ordered as: Zone I < Zone II < Zone III < Zone IV. It is recommended that water resource policies be turned to a more sustainable management strategy in areas with high WI and low WE. Zone I regions should be focused on particularly with limited resources and extreme exploitation. The results provide a valuable basis for macro-level decision-making concerned with regional sustainable development strategy for the entire mainland China.

Optimal reservoir operation using multi-objective evolutionary algorithms for potential estuarine eutrophication control

Increased nutrient loads and changed nutrient ratios in estuarine waters have enhanced the occurrence of eutrophication and harmful algae blooms. Most of these consequences are caused by the new proliferation of toxin-producing non-siliceous algae. In this study, we propose a multi-objective reservoir operation model based on 10-day time scale for estuarine eutrophication control to reduce the potential non-siliceous algae outbreak. This model takes the hydropower generation and social economy water requirement in reservoir into consideration, minimizing the ICEP (indicator of estuarine eutrophication potential) as an ecological objective. Three modern multi-objective evolutionary algorithms (MOEAs) are applied to solve the proposed reservoir operation model. The Three Gorges Reservoir and its operation effects on the Yangtze Estuary were chosen as a case study. The performances of these three algorithms were evaluated through a diagnostic assessment framework of modern MOEAs' abilities. The results showed that the multi-objective evolutionary algorithm based on decomposition with differential evolution operator (MOEA/D-DE) achieved the best performance for the operation model. It indicates that single implementation of hydrological management cannot make effective control of potential estuarine eutrophication, while combined in-estuary TP concentration control and reservoir optimal operation is a more realistic, crucial and effective strategy for controlling eutrophication potential of non-siliceous algae proliferation. Under optimized operation with controlled TP concentration and estuarine water withdrawal of 1470 m³/s, ecological satiety rate for estuarine drinking water source increased to 77.78%, 88.89% and 83.33% for wet, normal and dry years, the corresponding values in practical operation were only 72.22%, 58.33% and 55.56%, respectively. The results suggest that these operations will not negatively affect the economic and social interests. Therefore, the proposed integrated management approaches can provide guidance for water managers to reach a stable trophic control of estuarine waters.

Assessing Water Scarcity Using the Water Poverty Index (WPI) in Golestan Province of Iran

Population growth and rising water demand, climate change, severe droughts, and land-use changes are among the top severe issues in Iran. Water management in this country is sectoral and disintegrated. Each authority evaluates water based on its final intention and there is no commonplace indicator for evaluation programs. In this research, we used the Water Poverty Index (WPI) to map the status of water scarcity in a north-eastern province of Iran. Water poverty was measured based on five components of “Resources”, “Access”, “Capacity”, “Use”, and “Environment”. The scores on each component were then aggregated using the weighted multiplicative function, assuming equal weights for all components. The overall WPI was evaluated to be 41.1, signaling an alarming and serious water poverty in the study area. Based on the results, Azadshahr (29.1) and Gorgan (61.6) districts had the worst and the best conditions among all cases, respectively. To better understand the importance of WPI components, four weighting alternatives were used; however, none of them resulted in a tangible improvement of WPI index. The cross-correlation between the components was also evaluated, with Access and Capacity showing significant results. Leaving out “Capacity”, however, reduced WPI by 8.1. In total, “Access”, “Capacity”, and “Use” had the highest correlation with WPI, implying that any attempt to improve water poverty in the province must firstly tackle these issues. This study showed that WPI is an effective indicator of water scarcity assessment and could be used to make priorities for policy-making and water management.