水贫困 长江流域

As a basic natural and strategic resource, water is of great significance to the sustainable development of economies and societies. Owing to population growth, industrialization, the acceleration of urbanization, and global warming, water poverty is gradually increasing in some parts of the world. Effectively assessing water poverty from different dimensions is still a serious challenge for global water resources planning. This paper establishes a framework of multidimensional water poverty (MWP) from six dimensions: water management, water technology, water assets, water welfare, water resources, and water environment. The measurement model of MWP is built based on the Back Propagation Neural Network (BPNN), and the Spatial Correlation Analysis tool is used to visualize the spatial effects of MWP. The Yangtze River Economic Belt (YREB) was used as a case study and the main factors affecting the MWP of the YREB were determined by the Geodetector. When analyzing the results the following observations were made: (1) In terms of time distribution, the level of MWP in the YREB has gradually increased, and the poverty gap between the upper reaches, as well as the middle and lower reaches, shows an increasing trend. (2) With respect to spatial distribution, there is a continuously increasing agglomeration effect that shows a gradient-increasing distribution pattern of "West-Central-East." (3) The MWP in the YREB is mainly affected by these indicators in the three dimensions consisting of water resources, water technology, and water management. Specifically, R&D expenditure as a percentage of GDP, the proportion of water-saving irrigation area in the cultivable land area, the urban daily wastewater treatment capacity, the land surface water resources per capita, and the groundwater resources per capita play an important role in the MWP. Based on the above findings, targeted policy recommendations are proposed to alleviate the MWP in the YREB.

Under the influence of climate change and human activities, water scarcity and uneven spatial distribution have become critical factors constraining societal development and threatening ecological security. Accurately assessing changes in blue and green water resources (BW and GW) caused by human activities can reveal the actual situation of water scarcity. However, previous research often overlooked the calibration of GW and human water usage, and it rarely delved into the primary human factors leading to water scarcity and potential impact mechanisms. Therefore, based on the PCR-GLOBWB model that considers human impacts, and with reasonable calibration of B/GW and human water usage, hydrological processes were simulated under both human-influenced and natural conditions. A comprehensive assessment of the impact of human activities on BW and GW was conducted. The results show that: (1) BW and GW exhibit a spatial pattern of increasing from northwest to southeast in the basin. From 1961 to 2020, the proportion of BW showed an upward trend, while GW was decreasing; (2) The impact of human activities on changes in water resources is mainly concentrated in the midstream and dowmstream of the basin. Due to human influences, the green water flow (GWF) increased by 3-24.4 mm, and the BW volume increased by 67.2-146.4 mm. However, the green water storage (GWS) decreased by 5.6-75.4 mm; (3) The impact of human activities on blue water scarcity (BWscarcity) is significantly greater than green water scarcity (GWscarcity). The worsening of GWscarcity does not exceed 0.2, while areas where BW reaches significant deterioration (BWscarcity > 1.5) account for 1.3 %, 9.8 %, and 17 % of the upstream, midstream and downstream, respectively. (4) Irrigation activities are the main factor causing water resource scarcity. In the future, it is important to reasonably develop the potential for GW utilization and optimize BW management measures to address water resource crises.

Despite being one of the most abundant water resources globally, the Yangtze River Basin (YRB) region is facing substantial risks aggravated by climatic and anthropogenic changes. …

Water security is of great significance in social development, ecosystem sustainability, and environmental management. The Upper Yangtze River Basin (UYRB), which feeds >150 million people, is faced with aggravating water security risks due to more frequent hydrometeorological extremes and increasing human water withdrawals under a changing environment. Based on five RCP-SSP scenarios, this study systematically evaluated the spatiotemporal evolution patterns of water security in the UYRB under future climatic and societal changes. The future runoff was projected using Watergap global hydrological model (WGHM) under different Representative Concentration Pathway (RCP) scenarios and hydrological drought was further identified by the run theory. The water withdrawals were predicted based on the recently developed shared socio-economic pathways (SSPs). Then, a comprehensive risk index (CRI) for water security was proposed combining the degree of water stress and natural hydrological drought. The results show that the future annual average runoff across the UYRB is projected to increase, and hydrological drought tends to be more severe, especially in the upper and middle reaches. Dominated by water withdrawals in the industry sector, the future water stress in all sub-regions is estimated to increase substantially, with the largest change ratio of WSI in the middle future spatially ranging from 64.5 % to 301.5 % (66.0 % to 314.1 %) under RCP2.6 (RCP8.5). Based on the spatiotemporal variation of CRI, the UYRB is projected to face more severe comprehensive risks for water security in the middle and far future periods, and hotspot sub-regions are identified as Tuo River and Fu River, which are densely populated and economically prosperous, threatening regional sustainable social-economic development. These findings highlight the urgent need for adaptive countermeasures of water resources administration in response to more severe water security risks in the future UYRB.

… In five megacities in the Yangtze River basin, Chang et al. … of water poverty was developed for assessing water security in … basic data with the concept of water poverty. Among them, the “…

The process of urbanization, which leads to increased population density, changes in land use patterns, and heightened demand for industrial and domestic water use, exacerbates the contradiction between the supply and demand of water resources. This study examines the discrepancies between the supply and demand of water resources amidst urbanization, utilizing data from 110 cities within the Yangtze River Economic Belt (YREB) spanning from 2012 to 2021. The research employs the projection pursuit clustering model and the Dagum Gini coefficient method to evaluate the developmental status of water resources. While the Yangtze River Delta (YRD) region maintains a leading position with a water resources development score of 9.827 in 2023, there is a 2.2% increase in intra-regional disparity. The water resources development score for the City Cluster in the Middle Reaches of the Yangtze River (CCRYR) has experienced a decline, from 8.263 in 2012 to 8.016 in 2021; however, a reduction in intra-regional disparities has been observed since the implementation of the 2016 Outline of the Yangtze River Economic Belt Development Plan (YREBP), which suggests the policy’s efficacy. The Chengdu-Chongqing Economic Zone (CCEZ), despite its initially lower level of development, has demonstrated significant growth, with scores rising from 7.036 in 2012 to 7.347 in 2021. Collectively, the water resources development in the YREB exhibits an upward trend, yet the development remains uneven. The CCRYR shows a catching-up effect because of the YREBP, and the differences in other regions are widening. The research results provide decision-making support for water resources planning and management, and are of great significance in promoting the sustainable use of water resources.

Abstract Having intensive economic development and rapid urbanization, the Yangtze River basin, namely the heart of China’s prosperity, has faced challenges in the accompanying deterioration of water security. How to closely inspect the features and development of water security for the major cities in the basin and to compare the water security conditions between the major cities at the basin scope is a keystone to better support water management practice in the cities as well as regions. Hence, this study refined the previous framework by applying 19 indicators to describe the conditions of resource, infrastructure, waterway, efficiency, risk, and capacity and then integrated the data-driven weighting approach, the Criteria Importance Through Inter-criteria Correlation (CRITIC) method, to objectively evaluate the development and characteristics of water security of the megacities in the Yangtze River basin, i.e., Shanghai, Nanjing, Wuhan, Chongqing, and Chengdu, during 2011–2017. Based on the aggregated scores, Chongqing had the best overall water security condition (0.696) in 2017, followed by Chengdu (0.613), Shanghai (0.581), Nanjing (0.496), and Wuhan (0.471). During 2011–2017, Chongqing and Shanghai had a greater improvement in the water security condition, while Wuhan had the least. From a basin perspective, the upstream megacities had the advantage of their water availability and depletion conditions, river quality, pollutant discharge, government’s support of water affairs, and the societal investment in water conservancy. On the other hand, the middle- and downstream megacities had shown the better performance of the water affordability, the density of the sewage network, and water intensity. The sensitivity analysis detected the average of the standard variations of the score changes as 2.03% in the context of different indicator sets and thus assured the outcome robustness. This study enhances the assessment frameworks, facilitates the applications of temporal and spatial comparative evaluation of water security conditions on city and river basin level, and identifies the policy gaps for enhancing water management in the magacities and the basins.

… water vulnerability. This paper improves understanding of the status and trends of water resources in the Yangtze River Basin. … driving forces of water scarcity. Integrated assessment of …

… The Yangtze River Basin (YRB) is a region of vital economic and ecological importance in China, facing challenges of water scarcity and flooding underpinned by complex, yet …

… water-related aspects, as well as a conceptual framework to organize all indicators and variables. Firstly, we develop water poverty … of the Yangtze River, with a dense water network and …

… water to other cities, thereby exacerbating local water stress of these cities. The inter-city virtual water flows within the Yangtze River … the inequality of urban water scarcity among cities …

… great importance to comprehend and solve water security problems. This study analyzed the characteristics of drought and flood alternation in the Yangtze River Basin (YRB) based on …

… Of these provinces, Hubei and Anhui are located in the Yangtze River basin and they receive a large inflow from the river and its tributaries. This greatly increases their actual …

Grain production consumes a large amount of water and is affected by the degree of water scarcity and participation in the grain trade in various regions. The grain trade has changed the food security risks in regions where grain exports and imports. Therefore, it is crucial to consider regional water scarcity to understand food security risks from the grain trade network. Here, we construct a new framework for measuring regional food security risks associated with water scarcity, grain production, and grain trade based on a cross-city grain trade network combined with virtual water flows to evaluate the regional food security risks in the Yangtze River Delta region (YRD) of China in 2017. The results show that under the current domestic grain trade pattern in China, the YRD and its four provincial-level administrative regions are in a net grain import state. The grain trade within the YRD is concentrated in exports from the two major grain-producing areas of Anhui and Jiangsu to Zhejiang and Shanghai, especially from northern Jiangsu to southeastern Zhejiang. The net import results of virtual blue water in most cities indicate that the YRD has shifted its water resource pressure to other grain exporting regions in China, with Shanghai and Zhejiang being the greatest beneficiaries. Extreme risk only exists in Shanghai, and severe and moderate risks are concentrated in Jiangsu. The current grain trade has reduced the overall food security risk in the YRD by 1.3 % but increased the risks in Shanghai and Zhejiang by 2.1 % and 0.8 % respectively. This study highlights the potential risks that excessive production of food in water-scarce areas in the grain trade system may bring to a stable food supply, providing useful information for a comprehensive understanding of the food and water security situation and for future trade-offs.

Inter-basin water transfer (IBWT) projects have been globally implemented as a long-term means to mitigate water scarcity. However, the effectiveness of IBWT in mitigating future water scarcity under non-stationary climate conditions and socioeconomic changes remains unclear. This study presents the first sub-basin level assessment of future water scarcity in China under various climate change and socioeconomic scenarios (2025-2099). Based on a newly compiled database of 140 IBWT projects in China by 2050, here we present an assessment of their effect on future water scarcity at the sub-basin level. The results indicated that the water scarcity in China will aggravate in the future without IBWT under various climatic and socioeconomic scenarios. While IBWT will impact 60 sub-basins in China out of a total of 76 sub-basins, it will hardly change a sub-basin's water scarcity level (WSL). Around 696 million people will benefit from IBWT with alleviated water scarcity in the water-receiving sub-basins. The spatial disparity between water availability and demand in China will be reduced by IBWT, as the inequality coefficient will decrease from the historic value of 0.641 to 0.604. However, this study unravels the "IBWT-induced water scarcity" demonstrated by the negative impacts of IBWT on the water-exporting regions. Around 349 million people in China will be subjected to aggravated water scarcity in the future after IBWT, mainly in the southern sub-basins. The water scarcity analysis combined projected hydrological shifts and sectoral water demands in China, underscoring the challenges of securing water supply through interregional transfers.

Inadequate water quality can mean that water is unsuitable for a variety of human uses, thus exacerbating freshwater scarcity. Previous large-scale water scarcity assessments mostly focused on the availability of sufficient freshwater quantity for providing supplies, but neglected the quality constraints on water usability. Here we report a comprehensive nationwide water scarcity assessment in China, which explicitly includes quality requirements for human water uses. We highlight the necessity of incorporating water scarcity assessment at multiple temporal and geographic scales. Our results show that inadequate water quality exacerbates China’s water scarcity, which is unevenly distributed across the country. North China often suffers water scarcity throughout the year, whereas South China, despite sufficient quantities, experiences seasonal water scarcity due to inadequate quality. Over half of the population are affected by water scarcity, pointing to an urgent need for improving freshwater quantity and quality management to cope with water scarcity. The impact on inadequate water quality on water scarcity is unclear. Here the authors quantify China’s present-day water scarcity and show that inadequate water quality exacerbates China’s water scarcity, which is unevenly distributed across the country.

Abstract The ability of Gravity Recovery and Climate Experiment (GRACE) to monitor large scale drought events has been explored well during past few years. We develop an alternative method viz.,weighted water storage deficit (WWSD) to characterize drought events over Yangtze river basin (YRB) based on water storage deficit (WSD) method by combining GRACE RL06 sphere harmonic (SH) coefficient data and WaterGAP Global Hydrology Model(WGHM) data. We use component contribution ratio (CCR) of single terrestrial water compartment as weight to compute WWSD, comparing with other commonly employed drought indices and precipitation data from Global Precipitation Measurement(GPM). The results show that precipitation is the major trigger of water storage variation over YRB, which both have significant seasonal change. Our findings also indicate different terrestrial water component contributes distinctly to terrestrial water storage (TWS) variability and responds differently to drought features in YRB according to water component storage deficit (WCSD). Eleven drought events are identified in YRB based on WWSD with 2003, 2006 and 2011 experiencing the severest drought with drought intensity of −1.22 cm, −1.34 cm and −1.02 cm, respectively. Our study suggests that it is more realistic and reasonable to treat water components unequally to construct drought index derived from GRACE.

Droughts are some of the worst natural disasters that bring significant water shortages, economic losses, and adverse social consequences. Gravity Recovery and Climate Experiment (GRACE) satellite data are widely used to characterize and evaluate droughts. In this work, we evaluate drought situations in the Yangtze River Basin (YRB) using the GRACE Texas Center for Space Research (CSR) mascon (mass concentration) data from 2003 to 2015. Drought events are identified by water storage deficits (WSDs) derived from GRACE data, while the drought severity evaluation is based on the water storage deficit index (WSDI), standardized WSD time series, and total water storage deficit (TWSD). The WSDI is subsequently compared with the Palmer drought severity index (PDSI), standardized precipitation index (SPI), standardized precipitation evapotranspiration index (SPEI), and standardized runoff index (SRI). The results indicate the YRB experienced increased wetness during the study period, with WSD values increasing at a rate of 5.20mm/year. Eight drought events are identified, and three major droughts occurred in 2004, 2006, and 2011, with WSDIs of -2.05, -2.38, and -1.30 and TWSDs of -620.96mm, -616.81mm, and -192.44mm, respectively. Our findings suggest that GRACE CSR mascon data can be used effectively to assess drought features in the YRB and that the WSDI facilitates robust and reliable characterization of droughts over large-scale areas.

Abstract. The increasing conflicts for water resources between upstream and downstream regions appeal to chronological insight across the world. While the negative consequence of downstream water scarcity has been widely analyzed, the quantification of influence of upstream water use on downstream water scarcity has received little attention. Here non-anthropologically intervened runoff (natural runoff) was first reconstructed in upstream, middle stream and downstream regions in China's 12 large basins in the 1970s to 2000s time period using the Fu–Budyko framework, and then compared to the observed data to obtain the developmental trajectories of water scarcity, including the ratio of water use to availability (WTA) and the per capita water availability (FI; Falkenmark Index) on a decadal scale. Furthermore, a contribution analysis was used to investigate the main drivers of water scarcity trajectories in those basins. The results show that China as a whole has experienced a rapid increase of WTA stress with surface water use rapidly increasing from 161 billion cubic meters (12 % of natural runoff) in the 1970s to 256 billion cubic meters (18 %) in the 2000s, with approximately 65 % increase occurring in northern China. In the 2000s, the increase of upstream WTA stress and the decrease of downstream WTA stress occurred simultaneously for semi-arid and arid basins, which was caused by the increasing upstream water use and the consequent decreasing surface water use in downstream regions. The influence of upstream surface water use on downstream water scarcity was less than 10 % in both WTA and FI for humid and semi-humid basins during the study period, but with an average of 26 % in WTA and 32 % in FI for semi-arid and arid basins. The ratio increased from 10 % in the 1970s to 37 % in the 2000s for WTA and from 22 % in the 1980s to 37 % in the 2000s for FI. The contribution analysis shows that the WTA contribution greatly increases in the 2000s mainly in humid and semi-humid basins, while it decreases mainly in semi-arid and arid basins. The trajectories of China's water scarcity are closely related to socioeconomic development and water policy changes, which provide valuable lessons and experiences for global water resources management.

… This study focuses on the Yangtze River Economic Belt (YREB), … Demand-driven scarcity has emerged as the foremost … reaches, and the downstream Yangtze River Delta city cluster …

… In this study, based on the improved water stress index (WSI), we … basin zones) spatio-temporal status of WSI in the four major basins of the Huang, Huai, Hai and Yangtze River Basins (…

… The results revealed a decreasing trend in drought-prone areas. The overall vegetation … posed by water scarcity. More areas in the YRB are affected by water shortages than surpluses …

… ) Aqueduct Water Risk framework to analyze the baseline water stress and groundwater stress … are located in the Yangtze River Basin and the Pearl River Basin, the top two Chinese …

… water resources in dry seasons, which will dramatically reduce the discharge to the sea; (3) an ongoing large-scale water transfer from the Changjiang River … progressive water shortage …

… If water shortage in the Changjiang reaches a crisis point, it … the Changjiang basin, especially the MLRCR basin since the … ] The Changjiang river basin experienced extreme drought in …

In this study, we examine the spatial and temporal characteristics of water stress in China for the historical (1971–2010) and the future (2021–2050) periods using a multimodel simulation approach. Three water stress indices (WSIs), that is, the ratios of water withdrawals to locally generated runoff (WSIR), to natural streamflow (WSIQ), and to natural streamflow minus upstream consumptive water withdrawals (WSIC), are used for the assessment. At the basin level, WSIR estimates generally match the reported data and indicate severe water stress in most northern basins. At the grid cell level, the WSIs show distinct spatial patterns of water stress wherein WSIR (WSIQ) estimates higher (lower) water stress compared to WSIC. Based on the WSIC estimates, 368 million people (nearly one third of the total population) are affected by severe water stress annually during the historical period, while WSIR and WSIQ suggest 595 and 340 million, respectively. Future projections of WSIC indicate that more than 600 million people (43% of the total) might be affected by severe water stress, and half of China's land area would be exposed to stress. The found aggravating water stress conditions could be partly attributed to the elevated future water withdrawals. This study emphasizes the necessity of considering explicit upstream and downstream relations with respect to both water availability and water use in water stress assessment and calls for more attention to increasing levels of water stress in China in the coming decades.

… The model clarified the impact of irrigation on eco-hydrological processes and predicted hydrologic change after TGD and SNWTP to estimate whether dilemmas between water stress, …

… basins. Global warming is expected to amplify this imbalance, … water scarcity in the Yellow and Yangtze River basins and increasing scarcity in the Indus and Amu Darya River basins. …

The Yangtze River Basin serves as the socioeconomic core of China, and rapid development in recent years has intensified the conflict in the area between economic growth and ecological conservation. This study evaluated the spatiotemporal evolution of the land ecological security (LES) across 11 provinces and municipalities in the Yangtze River Basin from 2008 to 2023 by using the framework of the drivers, pressures, state, impact, and response model of intervention. We forecasted the trends of LES (2024–2033) by using a grey prediction model and identified the key obstacles to it through an obstacle degree model. The findings revealed the following: (1) Economic density (D3) and per capita water resources (S4) had significantly high weights, disproportionately impacting LES. Shanghai scored highest for Drivers, Impact, and Response subsystems, while Tibet led in Pressures and State. (2) Basin-wide LES scores improved from “less safe” to “critical safe” but saw no fundamental breakthrough. LES exhibited a three-tier spatial pattern: higher in the middle-lower reaches (e.g., Shanghai, Jiangsu) and lower in the upper reaches (e.g., Qinghai). Tibet remained “critical safe” with minor fluctuations; other regions improved gradually yet mostly remained “less safe” or “critical safe”. (3) Forecasts (2024–2033) indicate continued overall LES improvement. Shanghai and Jiangsu are projected to reach “safe” status, Qinghai will remain “unsafe”, while most others persist as “critical safe”. Basin LES remains fragile, requiring intervention. (4) The Drivers (D) and State (S) subsystems were the primary constraints on LES. Critical obstacle indicators included economic pressure (per capita GDP (D2), D3), resource availability (S4, ratio of effectively irrigated area (I1)), land productivity (agricultural/forestry output per unit area (I3)), and forest coverage rate (R6). Enhancing LES necessitates implementing regionally tailored policies addressing spatial variations, prioritizing urban economic optimization, strengthening water resource management, and ensuring effective cross-regional governance.

… factors that give rise to the risk of water insecurity in Shanghai. There is an extensive and … This is followed by a discussion of the trends in water availability in the Yangtze catchment, …

… on the spatial–temporal dynamics of water security with considering water disaster risk index (WDRI), water environment risk index (WERI), and water supply–demand. WERI centers on …

The security of water resources is of great importance to long-term sustainability. In order to better ensure the security of water resources, a significant link is to conduct water resources security evaluation, which should be considered from many perspectives as it involves natural reserves, social production, the efficiency of use, and environmental protection. In this paper, a fuzzy analytic hierarchy process sort (AHPSort) II-entropy weight (EW) method for regional water resources security evaluation is proposed based on the security of visible water and virtual water. Firstly, this paper takes into account the criterion of efficiency of water use in addition to two other criteria of quantity of water resources, pressure on water resources to establish a comprehensive water resources security evaluation system. Secondly, a combination method of hesitant fuzzy language judgment and entropy weight is employed to obtain the weight of each indicator. Thirdly, AHPSort II is used to classify the security levels of the evaluated regions, in which the security levels of regional water resources are divided into five levels. Furthermore, a case study on the cities of Hubei province, China, is conducted to show the applicability of the proposed method, the effectiveness, and reliability of the method are then verified by being compared with a subjective method and an objective method as well as sensitivity analysis. Finally, according to the comprehensive evaluation results, specific management suggestions for improving the water resources security in the case are put forward.

… , have caused devastation across the Yangtze River basin. If … and hydrologically diverse as the Yangtze River. First, the … coordination through the Yangtze River Protection Law. Second, …

Abstract Gansu Province in Northwest China faces serious water shortage, water pollution and fragile ecological environment, which have posed great threats to regional water security (WS). The WS assessment (WSA) is of great significance for regional sustainable development. In this study, WSA for 17 basins in the three regions (Yangtze River, Yellow River, and inland rivers) of Gansu Province in 2015, 2020, and 2030 was performed. Combined with relative carrying capacity (RCC) and integrated vulnerability (IV), a multistage integrated water security assessment (MIWSA) was proposed. The MIWSA controls the RCC and vulnerability in the water quantity and quality subsystems to achieve WSA of water resources system. Results show that the WS shifts from the security grade of the Yangtze River region in Southeast Gansu to the insecure grade of the inland river region in Northwest Gansu. Close internal relationship between WS, RCC, and IV makes a basin with high RCC grade and low IV grade have high WS grade. Measures and suggestions of water resource planning and management were proposed to improve regional WS grade. The MIWSA has good applicability and the ability to conveniently evaluate regional WS in the water resources system. Risk-based WSA in Gansu Province should be a potential research direction worth considering in future.

At the current stage, water resource shortages and significant regional disparities in resource distribution severely restrict China’s food security. Existing research primarily focuses on resource use efficiency, while lacking a systematic framework to distinguish between equality and equity in the coupled distribution of irrigation water, grain production, and nitrogen pollution across major river basins. The core objective of this study is to utilize the Concentration Index (CI) to construct a unified equity assessment framework, quantify the evolution of equality and equity in irrigation water use, grain production, and nitrogen loss to surface water in different river basins in China from 1992 to 2017, and determine the key influencing factors. For positive production resources, a distribution that benefits low-income groups is equity, while for pollution burdens, this distribution pattern is inequity. The results show that water shortages in Northern China have intensified, and higher income groups have obtained excessive benefits. The distribution of grain production has shifted from favoring higher income groups to favoring low-income groups, with the Concentration Index changing from 0.214 to −0.052, indicating an enhancement in equity. Irrigation water use has shown a certain degree of improvement, with the CI dropping from 0.023 to 0.017. However, nitrogen loss to surface water has exacerbated environmental inequality, with the CI dropping from 0.10 to 0.03, indicating that pollution burdens have shifted to low-income groups. Changes in equity across the country are driven by a small number of high-intensity grain production areas, and the key influencing factors include food security policies, urbanization, population size, and nitrogen fertilizer application. An asymmetric coupling relationship exists between water resource shortages and equity, and the regional economic foundation determines the formation of synergy or trade-offs. The findings underscore the necessity of transitioning from efficiency-focused to equity-focused agricultural governance in China. Targeted policies should include cross-basin ecological compensation mechanisms, differentiated technology promotion strategies, and integrated water–food-pollution management systems to balance food security, environmental protection, and social justice.

The Yangtze River Economic Delta (YRED) faces inequality in water use in large proportions due to rapid industrialization. This study adopted the Gini coefficient and Global Moran’s index to calculate inequality, its spatial spread and water use efficiency of cities in the YRED and categorized them into types based on the spatial spread of inequality. In general, inequality is reducing, but water use efficiency is poor. Inequality was rated 0–1; zero being the highest equality while 1 indicates the highest inequality. There is relatively high inequality (0.4–0.5) in Shanghai, Suzhou and Hefei. Most cities (20), however, showed equality (below 0.2). Nine (9) cities showed relative equality (0.2–0.3), while Wuxi, Bengbu and Zhenjiang were neutral (0.3–0.4). No city scored above 0.5. Water use efficiency in the majority of cities was poor. Only 11 out of 35 cities scored more than 50% efficiency. Poor irrigation, income and industrial water demand are the factors driving inefficiency and inequality. The categorization of cities into groups produced nine city types according to the spatial disposition of inequality. A combined effort to formulate policies targeting improved water use efficiency, reduced industrial consumption and improved irrigation, tailored towards the specific situation of each city type, would eliminate inequality.

… more pollutants to drinking water sources along the Yangtze River Basin or only assess the vulnerability of drinking water sources along the Yangtze River Basin. Few studies combine …

… Drought-induced ecological vulnerability is intensifying under global climate change, … Using the Yangtze River Basin (YRB) as a case study, we constructed a Drought Vulnerability …

Abstract Due to climate change and intensive human activities, the frequency and severity of water-related disasters have increased and resulted in socio-economic and environmental damages. Assessment of water-related disaster risk is essential for risk mitigation and management for sustainable development. To investigate these issues, this study examined hazard, exposure, vulnerability, and resilience to disaster in the Yangtze River Economic Belt (YREB) of China, where water-related disasters have had an adverse impact on economic development and water resource security. We developed a multiple index system for the concerned YREB 131 cities, applied a risk assessment model to assess the spatio-temporal dynamics of the water-related disaster risk and identified the hotspots of risks in the YREB from 2000 to 2015 based on multisource observation data. The results showed that the average hazard, exposure, and vulnerability increased by 3.62%, 1.28%, and 2.07%, respectively, in the YREB during 2000–2015, revealing that water-related disaster risk presented an upward trend. The high-risk areas were mainly located in the middle and lower reaches of the YREB. The water-related disaster risk for the Chengdu-Chongqing City Cluster and urban agglomeration of the Yangtze River Delta increased and had spatial agglomeration characteristics. In addition, cities’ resilience can contribute to 14%–25% decreases in water-related disaster risk in the YREB. Thus, policy makers should focus more attention on water-related disaster risk reduction and improve cities’ resilience, especially in the middle and lower reaches of the YREB.

Inter-basin water transfer (IBWT) projects offer us a long-term means to minimize the mismatch between water demand and water availability. Climate change may impose significant vulnerability to IBWT projects through perturbations in water availability. However, previous studies of climate change’s impacts on IBWT’s vulnerability are mainly based on a top-down framework, i.e. forecasting the climate change via a wide range of GCMs, which may underestimate the uncertainty of climate change. In order to address this problem, a bottom-up vulnerability assessment framework is developed to evaluate the vulnerability of IBWT. In this framework, an IBWT vulnerability indicator is proposed based on three dimensions of vulnerability including exposure, sensitivity and adaptive capacity. The framework also highlights the deep uncertainty of climate change by adopting a probabilistic Budyko model, which can estimate the water availability over a broad range of climate futures. The South-to-North Water Transfer Project (SNWTP) in China is adopted as a case study to illustrate the effectiveness of the proposed framework. It shows that the framework is a useful tool for identifying the detrimental climate condition scope for the IBWT’s vulnerability, and is valuable to guide long-term water resources management and planning for policymakers.

… constructs an evaluation index system for the vulnerability of the WEFE system. The cross-… system vulnerability and analyze its mechanism based on the theory of disaster vulnerability …

… ecological environment, water resources system vulnerability (WRSV… In this study, the Upper Yangtze River (UYZ) located in … of the basin and the area ratio for medium vulnerability and …

Abstract A clear understanding of the changes of water resources under the background of environmental changes is of great significance for scientific management and utilization of water resources in China. This study systematically analyzed the spatial-temporal variations of surface water resources in China since 2000. Water vulnerability in current (2010s) and its trends from 2000 to late-2010s in different regions of China were also summarized. In addition, the correspondingly adaptive measures to counter regional risks to water resources were proposed. We concluded that the runoff of major rivers had been decreasing in eastern China and increasing in western China during 2000‒2018. In the arid area of Northwest China, the alpine runoff has shown an overall upward trend since the late-1990s/early-2000s, with a 10%‒25% increase caused by the increase of glacial meltwater and precipitation. While the runoff of each hydrological station in the 2000s‒2010s was 34.7% lower than that in the 1950s‒2010s on average. The increases in precipitation and glacial meltwater with global warming caused a rapid expansion of lakes in the Qinghai-Tibet Plateau and Xinjiang, thus leading to an increase in total area and water quantity of lakes in China from 1995 to 2015. The mean contribution rates of climate change and human activity to runoff change in river basins of China were 53.5% and 46.5%, respectively, during the period of 2000‒2010s. The driving factor of runoff change in many river basins has gradually changed from climate change (1950s‒2000) to human activity (2000‒2018). During 2000‒2018, the contributions of human activities to runoff change were 50%‒80% in major rivers of eastern China. The vulnerability in most areas of Northwest China and North China is generally high, with the vulnerability index greater than 0.6. Comparatively, in Northeast, East, South, and Central China, it is lower or not vulnerable. In Southwest China, the vulnerability varies greatly with Yunnan and Sichuan relatively low while Chongqing and Guizhou relatively high. The precipitation increase, the application of water-saving technology, the establishment of flood control and drought relief engineering facilities, and the introduction of relevant policies and measures have helped to gradually reduce the vulnerability of water resources in most areas of North and Northwest China (except Xinjiang) from 2000 to 2010s. Water vulnerability has been increasing in southern China, caused by climate change and the development of industry and agriculture, which increases water resource exposure since 2000. Based on the typical risk factors and vulnerability characteristics of water resources in different regions, this study proposed some targeted adaptive measures correspondingly so as to scientifically deal with the problems of surface water resources in China.

China is undergoing a rapid transition from rural to urban dominated economy. Economy is booming, social structures are changing, ecosystems are stressed, and sustainability is challenged. We analysed the socioeconomic and environmental vulnerability of river systems that are entirely or partly located in the continental part of China. One-third of the mankind inhabit the area covered by this study. Six stress factors (governance, economy, social issues, environment, hazards and water stress) were analysed separately and in combination as an overall vulnerability. China's most vulnerable parts were found to be situated in the lower Hai and Yellow River basins, with their high population density, low water availability and high human footprint. The other water-stressed areas in the northwest showed high vulnerability, too, and so did the water-rich coastal areas due to high population density, natural hazards and high human footprint. We went beyond existing water stress and vulnerability studies in three dimensions. First, our perspective was highly multidimensional and thus very relevant in addressing China's water challenges in a realistic and multifaceted way. Second, we combined administrative and river basin scales and used an essentially higher spatial resolution than done so far. Third, we included the transboundary dimension, which is not customary. This is highly important since one billion people China's neighbouring countries, in basins that are partly in China.

… the Standardized Water Supply–Demand Index (SSDI), based on the water balance method … and temporal distribution of the drought characteristics in the Yangtze River Basin (YRB). …

… of water supply–demand imbalance in the Yangtze River Economic Belt (YREB), considering both water … Effective management must consider spatial differences and both water quantity …

… Yangtze River Economic Belt (YEB) in China to analyze the dynamics of the spatial equilibrium of its water … perspectives, resulting in spatial inequality of water resources. While it is …

This study used a two-stage network data envelopment analysis model to measure the water use efficiency of 108 cities in the Yangtze River Economic Belt in the initial water use and wastewater treatment phases from 2009 to 2019. We used the Dagum Gini coefficient to decompose the urban water use efficiency of six major urban clusters in the Yangtze River Economic Belt. We also used σ convergence and β convergence types to test the convergence characteristics of urban water use efficiency of six major urban clusters in the Yangtze River Economic Belt. This study found that the overall low level of water use efficiency in cities in the Yangtze River Economic Zone mainly stems from the low level of water use efficiency in the wastewater treatment stage. The 108 cities in the Yangtze River Economic Zone are divided into four types based on the average values of water use efficiency in the initial use and wastewater treatment phases; the highest number of cities are in the double-low category, with low average values of water use efficiency in the initial use and wastewater treatment phases. During the study period, spatial differences in urban water use efficiency in the Yangtze River Economic Zone narrowed, with the differences stemming mainly from hyperdensity, followed by intra- and inter-regional differences. Meanwhile, there is convergence in urban water use efficiency in the Yangtze River Economic Belt; significant β convergence in the urban agglomerations of the Yangtze River Delta, Jianghuai, middle reaches of the Yangtze River, Chengdu–Chongqing, and Central Yunnan; and insignificant β convergence in the Central Qian urban agglomeration. After considering control factors, such as industrial structure, financial development level, environmental regulation, economic development level, and science and education development level, the water use efficiency of the six major urban clusters in the Yangtze River Economic Belt converges faster, but the influence of these control factors on the water use efficiency of each urban cluster is heterogeneous. Research results have reference value for the development of improvement strategies on differentiated urban water use efficiency in the Yangtze River Economic Belt.

Virtual water exerts an essential effect on water resources, yet such effect is rarely considered in current studies on water rights allocation in transboundary rivers. Hence, this paper ran a case study on Taihu Lake Basin, collecting data from 2017 to make clear the physical water rights of four regions—Jiangsu Province, Zhejiang Province, Anhui Province, and Shanghai City—in the Basin. After that, the multiregional input–output (MRIO) approach was utilized to measure the trade in value-added (TiVA) transfer and virtual water transfer (VWT) and construct an inequality index of VWT (VWI). Next, water efficiency coefficient was employed to convert the VWT into riparian level. Finally, VWT and VWI were incorporated into the water rights allocation model to form up a water rights allocation scheme for Taihu Lake Basin. Results showed: (1) Jiangsu enjoys the most allocated physical water rights, followed by Zhejiang, and Anhui ranks the lowest; (2) Anhui and Jiangsu are net virtual water exporters (2.259 billion m3 and 1.78 billion m3, respectively), while Zhejiang and Shanghai are net importers (2.344 billion m3 and 1.695 billion m3, respectively); (3) Anhui suffers the most inequality—0.4401—followed by 0.5076 of Jiangsu, while Zhejiang has the most equal environment—0.7012; (4) after the inclusion of virtual water, the quantity of water rights allocation changes, whereas Anhui experiences the largest growth—144 million m3—due to the dual effects from the highest VWT and inequality. In conclusion, the effect of virtual water is indispensable, so VWT and VWI should both be considered in the physical water rights allocation of transboundary rivers.

… Inequality in water allocation and the shortage of water resources are two of the main critical components of multi-regional water system management. The impact of virtual water flows …

Study region Yangtze River Economic Belt, China Study focus As the major national strategic development area of China, there have always been vital problems about imbalance of the …

… , the problems of low effective utilization rate and uneven spatial distribution of agricultural irrigation water in the Yangtze River Economic Belt (YREB) are becoming increasingly …

… of water through low-value products without sufficient compensation, leading to a spatial mismatch between water … While inter-city trade reduces overall water use inequality (W-Gini …

… ’ s Yangtze River Economic Belt) as a case study, the multiscale disparity of comprehensive … to test the disparity of urban comprehensive carrying capacity. Furthermore, the multiscale …

… the Yangtze River Basin and monthly runoff of the Yangtze River… changes of water resources during the flood season in which … The focus on flood season instead of working with annual …

The Yangtze River Estuary (YRE) is vulnerable to the accelerated sea level rise (SLR). In this study, a three-dimensional hydrodynamic and salinity transport model, with a high …

… water cycle model of the upper reaches of the Yangtze River (URYR) is established based on the improved Soil and Water … Water is stored in flood season and released in dry season, …

… Using the Yangtze River Basin as a case study, the results show that western Sichuan and … (9.62%); high-hazard events exhibit weak seasonal dependence and broader spatial impact. …

The multi-objective optimal operation and the joint scheduling of giant-scale reservoir systems are of great significance for water resource management; the interactions and mechanisms between the objectives are the key points. Taking the reservoir system composed of 30 reservoirs in the upper reaches of the Yangtze River as the research object, this paper constructs a multi-objective optimal operation model integrating four objectives of power generation, ecology, water supply, and shipping under the constraints of flood control to analyze the inside interaction mechanisms among the objectives. The results are as follows. (1) Compared with single power generation optimization, multi-objective optimization improves the benefits of the system. The total power generation is reduced by only 4.09% at most, but the water supply, ecology, and shipping targets are increased by 98.52%, 35.09%, and 100% at most under different inflow conditions, respectively. (2) The competition between power generation and the other targets is the most obvious; the relationship between water supply and ecology depends on the magnitude of flow required by the control section for both targets, and the restriction effect of the shipping target is limited. (3) Joint operation has greatly increased the overall benefits. Compared with the separate operation of each basin, the benefits of power generation, water supply, ecology, and shipping increased by 5.50%, 45.99%, 98.49%, and 100.00% respectively in the equilibrium scheme. This study provides a widely used method to analyze the multi-objective relationship mechanism, and can be used to guide the actual scheduling rules.