Search Results (220)

Spatial heterogeneity in economic benefits of water use provides crucial evidence for the evaluation of water diversion projects and the spatial equilibrium of water resource allocation. Using city-level data from 2017 on the sectoral water use and value added in 334 Chinese cities, we estimated the economic benefits of water use in the agricultural, industrial, and service sectors using the allocation coefficient method. We then revealed the spatial heterogeneity combining an exploratory spatial data analysis (ESDA) method. For the agricultural sector, the high economic benefit of water use regions are primarily concentrated on both sides of the “Hu Huanyong Line”; regions with high economic benefit of industrial water use are mainly found in the North China Plain, the middle and lower Huanghe River basin, the Yangtze River Delta, the Pearl River Delta, Chongqing and Chengdu, and the economic benefit of service water use is higher in the north than in the south. ESDA provides significant evidence for the analysis of spatial heterogeneity with regard to the economic benefits of water use in China. Based on the fundamental distribution of water resources and the spatial heterogeneity in the economic benefits of water use, potential water diversion areas can be preliminarily identified. The Haihe River Basin in the North China Plain and some areas in the southeast coastal region are potential receiving areas, and the eastern regions of Southwest China with abundant water resources and lower elevations, along with the middle and lower reaches of the Yangtze River are potential source areas. Further research about marginal benefits and water use costs, along with dynamic updates, is required for water resource allocation of China. Full article

Groundwater in the Nansi Lake Basin, a key reservoir of the South-to-North Water Diversion Project, supports domestic, agricultural, and ecological needs but faces pressure from overexploitation and pollution. This study clarifies the hydrochemical characteristics, controlling processes, environmental quality, and source contributions of shallow groundwater in the basin. Hydrochemical data from 67 wells were interpreted using Piper and Schukalev diagrams, Gibbs and ion-ratio plots, the entropy-weight water quality index (EWQI), and an absolute principal component scores–multiple linear regression (APCS-MLR) model. Groundwater shows high mineralization and hardness, with 35.82% and 55.22% of samples exceeding standard limits for total dissolved solids and total hardness, respectively. The dominant facies are HCO₃-Ca, HCO₃-Ca·Mg, and HCO₃·Cl-Na·Ca, indicating dissolution and ion exchange involving carbonate and silicate rocks. Gibbs and ion-ratio analyses demonstrate that rock–water interaction is the main control, with secondary influence from evaporation. EWQI results indicate generally good groundwater quality (68.66% Class I, 20.90% Class II). APCS-MLR identifies natural, agricultural, ion-exchange, and anthropogenic sources, contributing 53.34%, 22.71%, 4.79% and 19.14%, respectively. These findings show that protection should focus on pollution control in northern agricultural and mining zones while conserving high-quality groundwater elsewhere in the basin. Full article

Synthetic aperture radar (SAR) is an active microwave imaging system equipped with penetration capability, enabling all-time and all-weather Earth observation, and demonstrates significant advantages in large-scale surface water-body detection. Although SAR images can provide relatively clear water-body details, they are susceptible to interference from external factors such as complex terrain and background noise, resulting in fragmented detection outcomes and poor connectivity. Therefore, a Connectivity Refinement Network (ConRNet) is proposed in this study to address the issue of fragmented water-body regions in water-body detection results, combining HISEA-1 and Chaohu-1 SAR data. ConRNet is equipped with attention mechanisms and a connectivity prediction module, combined with dual supervision from segmentation and connectivity labels. Unlike conventional attention modules that only emphasize pixel-wise saliency, the proposed Dual Self-Attention Module (DSAM) jointly captures spatial and channel dependencies. Meanwhile, the Connectivity Prediction Module (CPM) reformulates water-body connectivity as a regression problem to directly optimize structural coherence without relying on post-processing. Leveraging dual supervision from segmentation and connectivity labels, ConRNet achieves simultaneous improvements in topological consistency and pixel-level accuracy. The performance of the proposed ConRNet is evaluated by con-ducting comparative experiments with five deep learning models: FCN, U-Net, DeepLabv3+, HRNet, and MAGNet. The experimental results demonstrate that the ConRNet achieves the highest accuracy in water-body detection, with an intersection over union (IoU) of 88.59% and an F1-score of 93.87%. Full article

Inter-basin water transfer projects (IBWTPs) play a crucial role in addressing the uneven spatial and temporal distribution of water resources and ensuring water security in the receiving areas. However, these projects are subject to various risk factors during their operation. While risk management is critical, current research in this field lacks a systematic and dynamic approach. A three-dimensional measurement model for probability, loss, and risk value, based on Dempster–Shafer (DS) evidence theory, Bayesian networks, and the equivalence method, was established in this study and, in consideration of the engineering characteristics of the IBWTP, a dynamic transmission evolution model for risk is constructed. The applicability and effectiveness of the model are demonstrated through a case study of the Central Line Project of South-to-North Water Diversion (CLPSNWD). The results indicate that the system risk of the CLPSNWD is in an unstable state, with the key influencing factors being channel engineering risk, flood disaster risk, pipeline engineering risk, and water transfer (discharge) cross-structure risk. The research findings offer a novel approach to the quantitative analysis and evolution of risk and contribute to the further development of engineering risk management theory. Full article

The South-to-North Water Diversion Project (SNWDP), the world’s largest water transfer initiative, is designed to address northern China’s acute water scarcity by diverting approximately 45 km³ of water annually from the south through three major routes, with completion targeted for 2050. This review demonstrates that the SNWDP has already improved water security for over 150 million people, stabilized groundwater, and supported agricultural and urban development, but also presents significant challenges, including escalating costs, large-scale resettlement, and substantial environmental concerns such as ecosystem alteration, salinity intrusion, pollutant transfer, and risks to biodiversity and water quality. While mitigation and adaptive management efforts are ongoing, their long-term effectiveness remains uncertain. Notably, the SNWDP’s influence extends beyond China: by enhancing food production self-sufficiency, it can help stabilize global food markets during concurrent droughts and serves as a model—albeit a debated one—for large-scale water management and governance. The project’s hydropolitical and geopolitical dimensions, especially regarding the planned western route and potential transboundary impacts, underscore the need for international dialog and monitoring. Overall, the SNWDP exemplifies both the opportunities and dilemmas of 21st-century megaprojects, with its legacy dependent on balancing economic, environmental, and social trade-offs and on transparent, participatory governance to ensure sustainable outcomes for China and the global community. Full article

The Danjiangkou Reservoir (DJKR) serves as the water source for the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP), yet comprehensive understanding of its ecosystem structure and function remains limited. This study addressed this knowledge limitation by developing an Ecopath model with 22 functional groups, parameterized using field survey data from 2022 to 2023. Our findings revealed a trophic structure spanning levels 1 to 3.59, with the highest level occupied by piscivorous mandarin fish (Siniperca spp.). Energy flowed through two dominant pathways, with the grazing food chain demonstrating higher transfer efficiency compared to the detrital pathway. Mixed trophic impact analysis identified the introduced icefish (Neosalanx taihuensis) as exerting substantial negative impacts on most functional groups. Key ecosystem indices, including the total primary production to total respiration ratio (TPP/TR, 1.99), connectance index (CI, 0.248), and system omnivory index (SOI, 0.113), collectively indicated an ecosystem of moderate maturity and stability. Persistent challenges include the proliferation of N. taihuensis, suboptimal energy transfer between trophic levels III and IV, and inefficient utilization of primary productivity. To enhance ecosystem resilience and maintain water quality, we recommend the targeted removal of icefish and strategic management of zooplanktivorous fish populations. Full article

Mining and smelting release potentially toxic elements (PTEs) that threaten ecosystems and public health. However, comprehensive risk assessments of PTEs across environmental media near mining areas remain scarce. The Laoguan River Basin is located in southwestern Henan Province, China. It lies within the water source area of China’s South-to-North Water Diversion Middle Route Project. This area has high geographic and ecological importance. In this study, we analyzed the pollution characteristics of PTEs in the water–soil–crop system. We also performed a source-oriented health risk assessment by integrating Monte Carlo simulation with source apportionment. According to this study, Mo and Sb were the predominant contaminants in soils and water. Pb, Cr, and Ni were elevated in crops. The health risk assessment indicated that PTEs in surface water were at acceptable levels. In contrast, PTEs in soils pose both non-carcinogenic and carcinogenic risks, particularly to children. The estimated risks were 1% (non-carcinogenic) and 64% (carcinogenic), with ingestion as the primary exposure pathway. Source apportionment showed that the surface water pollution was mainly linked to diverse mining activities. Soil pollution was jointly influenced by the geological background and mining and agricultural activities. Crop pollution was primarily associated with mining and agricultural activities. Geological background and mining were the main driving factors of the increased health risks for children. They accounted for 83% of the non-carcinogenic risk and 79% of the carcinogenic risk. Overall, these results are crucial for pollution control, safeguarding public health and safety, and promoting balanced economic and ecological development. Full article

Increasing climate change leads to the variability of dependencies among meteorological factors. Currently, the investigation of the interdependence of meteorological variables primarily focuses on the bivariate relationships, such as precipitation and temperature or precipitation and wind speed. However, the high-dimensional dependencies among multiple meteorological factors have not been thoroughly explored. This paper proposes a statistical analysis framework that comprehensively analyzes the changes in dependencies among meteorological factors. This statistical analysis framework is based on multivariate joint distributions and enables the detection of dependency change points as well as the analysis of drivers using total probability formulations and orthogonal experiments. Taking the Huang-Huai-Hai region, a recipient area of the South-to-North Water Diversion project, as the study area, we constructed a vine copula-based multivariate joint distribution for precipitation (Pre) and six meteorological factors: temperature (Tm), maximum temperature (Tmax), minimum temperature (Tmin), wind speed (Win), relative humidity (Rhu), and the Southern Oscillation Index (SOI). The results indicate that a change point exists in the dependence of the 7-dimensional variables (Pre and six meteorological factors) in the Huang-Huai-Hai region in 2013. Tmin, Win, and Tmax are the primary driving factors affecting the precipitation–meteorological dependency relationship. The cumulative distribution function (CDF) is used to describe the probability distribution of precipitation and related meteorological factors. The optimal CDF values of the multivariate joint distribution model were achieved with Rhu and Tmax at level 3, SOI and Tm at level 2, and Win and Tmin at level 1. The results can provide a theoretical method for testing the non-stationarity of high-dimensional meteorological variable dependencies and offer conditional probability support for constructing meteorological prediction machine learning models. Full article

Rocky desertification in the Danjiangkou Reservoir area, the core water source of the South-to-North Water Diversion Project, constitutes a significant ecological threat, primarily driven by historical deforestation and agricultural expansion. To addressing the previous lack of comprehensive evaluation and spatiotemporal analysis of rocky desertification in the Danjiangkou Reservoir area, this study utilized Google Earth Engine (GEE) and GeoDetector to analyze its evolution and driving factors from 1995 to 2022. The results indicated an overall improvement, with a 1002.02 km² decrease in the desertification-prone area and an expansion of 26,077.31 km² in the non-desertified area. However, desertification remains severe in the western and southeastern regions, while the northeastern and central areas showed relative stability. Notably, desertified areas decreased substantially between 1995 and 2022, reflecting the effectiveness of ecological restoration efforts. Key driving factors include potential evapotranspiration (PET), landform, elevation, and temperature, with interactions between PET and environmental variables exhibiting strong explanatory power. These findings highlight the complex interplay between natural and anthropogenic factors in desertification dynamics. Continuing human intervention is essential to restore vegetation, mitigate soil erosion risks, and ensure the long-term stability of the reservoir’s water resources. Full article

River water quality is a direct determinant of both drinking water security and regional economic vitality. However, the hydrochemical trajectories and solute provenance of agricultural streams remain only fragmentarily understood. Here, we examine the Jinqian River—a representative agricultural tributary of the Danjiangkou Reservoir source area for the South-to-North Water Diversion Project—by coupling hydrochemistry with multivariate statistics techniques. The results revealed that the pH values of the river water ranged from 7.55 to 8.30, indicating a weakly alkaline condition. During all three hydrological periods, the concentrations of total nitrogen (TN) exceeded the limits set by the Class Ⅲ surface water quality standards in China, suggesting that the agricultural river has been significantly impacted by human activities. Solute dynamics followed three rainfall-modulated patterns: (i) dilution-driven decreases in the flood season (e.g., Na⁺), (ii) concentration via flushing or evaporative concentration (e.g., SO₄²⁻), and (iii) reservoir-induced damping of seasonal contrasts (e.g., TN), the latter attributable to nitrogen retention behind upstream dams. Geochemical fingerprints reveal that Cl⁻ and Na⁺ originate predominantly from halite dissolution; Ca²⁺, Mg²⁺ and HCO₃⁻ from coupled carbonate–silicate weathering; and SO₄²⁻ from evaporite dissolution. Principal component analysis distills four dominant quality controlling factors: agricultural fertilizers, halite weathering, evaporite dissolution, and domestic effluent. These findings provide a quantitative basis for managing nutrient and salt fluxes in agricultural rivers and for safeguarding water sustainability within water-diversion source regions. Full article

Elite capture, a power structure problem involving rent-seeking, hinders sustainable water resources management. Governments play crucial roles in instilling public legitimacy in water governance, a common-pool resource that benefits from cooperative solutions such as pilot competitions, co-monitoring, and inter-agency coordination. A study of South-to-North Water Diversion Projects in China showed how, when governments outsource small projects to local sub-contractors, a method named moderate supervision (ruo jiandu) can enable effective oversight, which is superior to a bidding model with strict supervision (qiang jiandu). The concept of moderate supervision was initiated in 2023, before which most small projects had been left in a risky state with no supervision (ling jiandu). Analysis of a case in Shandong Yellow River Water Diversion Irrigation Area involved semi-structured in-depth interviews. Findings revealed that an elite-government-villagers tripartite spiral was composed of 3 dimensions reshaping a positive elite culture: first, a whitelist of qualified local contractors; second, co-monitoring of multiple stakeholders with influence exerted by a three-tier mobilization system; third, inter-agency coordination innovatively enabling smooth functioning between policy entrepreneurs of formal institutions and local social governance of informal ones. Policy implications to underscore real-world applicability are provided. Full article

China faces the persistent challenge of uneven spatiotemporal water resource distribution, constraining economic and social development while exacerbating regional disparities. Achieving co-evolution between water source systems and water use systems is thus a critical proposition in water resources management. Based on synergetics theory, this study takes Henan Province, a typical water-scarce social–ecological system, as the research object, and constructs a quantitative analysis framework for supply–demand bidirectional synergy. It systematically reveals the evolution patterns of water resource systems under the mutual feedback mechanism between water sources and water use. Findings indicate that between 2012 and 2022, the synergy degree of Henan’s water resource system increased by nearly 40%, exhibiting significant spatiotemporal differentiation: spatially “lower north, higher south”, and dynamically shifting from demand-constrained to supply-optimized. Specifically, the water source system’s order degree showed a “higher northwest, lower southeast” spatial pattern. Since the operation of the South-to-North Water Diversion Middle Route Project, the provincial average order degree increased significantly (annual growth rate of 0.01 units), though with distinct regional disparities. The water use system’s order degree also exhibited “lower north, higher south” pattern but achieved greater growth (annual growth rate of 0.03 units), with narrowing north–south gaps driven by improved management efficiency and technological capacity. This study innovatively integrates water source systems and water use systems into a unified analytical framework, systematically elucidating the intrinsic evolution mechanisms of water resource systems from the perspective of supply–demand mutual feedback. It provides theoretical and methodological support for advancing systematic water resource governance. Full article

The success and impact of biological invasions depend on adaptations to novel abiotic and biotic selective pressures. However, the genetic mechanisms underlying adaptations in invasive species are inadequately understood. Taenioides sp. is an invasive worm goby, originally endemic to brackish waters in the estuaries of Southeastern China, and now colonizes multiple inland freshwaters of North China within decades as a byproduct of the East Route of South-to-North Water Transfer (ESNT) project. However, the molecular mechanisms underlying their adaptations to the climate of North China, especially the temperature regime, are unknown. Here, we performed genomic resequencing analysis to assess genetic diversity and population genetic structure, and further investigated the genomic signatures of local adaptation in the invasive population of Taenioides sp. during their northward invasion. We revealed that all invasive populations exhibited no genetic differentiation but low gene flow and an obvious signal of population bottleneck. Yangtze River estuary may serve as the source population, while Gaoyou Lake serves as a potential bridgehead of the invasion. Selective sweep analyses revealed 117 genomic regions, containing 673 candidate genes, under positive selection in populations at the invasive front. Redundancy analysis suggested that local temperature variables, particularly the monthly minimum temperature, represent critical evolutionary forces in driving adaptive divergence. Functional enrichment analyses revealed that multiple biological processes, including metabolism and energy production, substance transmembrane transport, and neural development and synaptic transmission, may play important roles in adaptation to regional temperature conditions. Our findings revealed a scenario of adaptive evolution in teleost species that underpins their regional climate adaptation and successful establishment of invasive populations in a human-facilitated invasion context. Proper management strategies should be established to manage Taenioides sp invasion as soon as possible. Full article

Leveraging multi-source remote sensing datasets and dynamic groundwater monitoring well observations, this study explores the multiscale spatiotemporal linkages of groundwater storage changes and land deformation in North China Plain (NCP) after the South-to-North Water Diversion Project (SNWDP). Firstly, we employed Gravity Recovery and Climate Experiment (GRACE) and interferometric synthetic aperture radar (InSAR) technology to estimate groundwater storage (GWS) and land deformation. Secondly and significantly, we proposed a novel GRACE statistical downscaling algorithm that integrates a weight allocation strategy and GWS estimation applied with InSAR technology. Finally, the downscaled results were employed to analyze spatial differences in land deformation across typical ground fissure areas. The results indicate that (1) between 2018 and 2021, groundwater storage in the NCP exhibited a declining trend, with an average reduction of −3.81 ± 0.53 km³/a and a maximum land deformation rate of −177 mm/a; (2) the downscaled groundwater storage anomalies (GWSA) showed high correlation with in situ measurements (R = 0.75, RMSE = 2.91 cm); and (3) in the Shunyi fissure area, groundwater storage on the northern side increased continuously, with a maximum growth rate of 28 mm/a, resulting in surface uplift exceeding 70 mm. Full article

River source areas often face stricter environmental protection requirements, leading to external cost and development opportunity losses. Quantifying such losses is essential for designing ecological compensation mechanisms (payment for ecological services). Existing methods often lack scientific rigor and practical feasibility. A method based on the comparison of Cumulative Growth Rates of Per Capita GDP (CGR-PCGDP) is proposed and applied to the water source area of the Middle Route of the South-to-North Water Diversion Project (MR-SNWDP) in China. The method quantifies the fiscal opportunity losses by comparing the CGR-PCGDP between the water source area and a reference area, and deducting growth rate differences before the baseline year. Regions in closer proximity to the Danjiangkou Reservoir—the source point of water diversion—have been found to be more markedly affected by stricter protection policies, resulting in greater development opportunity losses. Shiyan City and Nanyang City experienced annual average fiscal opportunity losses of CNY 569 million and 371 million, respectively, whereas cities farther from the reservoir, such as Hanzhong City, Ankang City, and Shangluo City, incurred lower losses. Compared to traditional approaches, this method avoids overestimation and offers practical, evidence-based results. How factors like geographical location, economic structure, fiscal compensation, and economic transformation capacity affect losses is further discussed, and strategies for balanced development and effective ecological compensation are proposed. The study offers methodological and referential support for the establishment of ecological compensation standards in river source areas. Full article