Multiscale Water Balance Analysis and Water Network Resilience Optimization in the Yellow River Basin.

As a core region for ecological security, food production, and energy supply in China, the hydrological cycle of the Yellow River Basin is being profoundly altered by climate change and intensive human activities, leading to growing systemic water scarcity and increasingly heterogeneous hydrological processes. However, the lack of long-term and high-resolution hydrological data has constrained the accurate characterization of multilayer water exchange processes among the atmosphere, surface water, and groundwater at the basin scale, thereby limiting the development of sustainable water resource management strategies. This study integrates multisource remote sensing data with hydrological models to reveal the spatiotemporal evolution of the basin water cycle and to develop a resilience-oriented water network for sustainable management. By integrating remote sensing products such as GRACE and ETMonitor with distributed hydrological models, the study systematically evaluated the multilevel water balance dynamics of the Yellow River Basin from atmospheric precipitation to groundwater storage during 1991-2020. The results show that the remotely sensed groundwater storage anomaly (GWSA) agrees well with in situ groundwater-level observations at the regional scale. The ETMonitor model performs well in estimating evapotranspiration over vegetated areas, with a validation root mean square error (RMSE) of 0.93 mm/day. The study revealed a pronounced spatiotemporal pattern of "water surplus in the west and water deficit in the east" across the Yellow River Basin, with the polarization intensifying under the combined effects of upstream climatic warming and humidification and intensive water consumption in the middle and lower reaches. Based on improved intelligent algorithms and channel topology constraints, this study proposed an optimized basin water network scheme. After optimization, the areal extent of water-deficient regions decreased substantially, water stress in the middle and lower reaches was alleviated, and both the balance and the efficiency of basin-wide water allocation improved. This research provides a quantitative basis for refined water resource management, water-saving irrigation retrofitting, and optimized planning of the national water network in the Yellow River Basin.