Evolution and causes of water resources and water use in China from 2015 to 2024

Water resources, as fundamental natural assets and strategic economic resources, are crucial to national sustainable development amid rapid economic and social growth. Based on data on water resource and water usage across China’s ten primary water resource zones from 2015 to 2024, and incorporating findings from the Third National Water Resources Survey and Assessment, this study systematically analyzes the spatiotemporal evolution characteristics of water resources and water use in China during 2015—2024 using the Mann-Kendall test and Theil-Sen slope estimator. The results indicate that between 2015 and 2024, the total national water resources increased by 2.08% compared to the baseline value of the Third National Water Resources Survey and Assessment, showing a spatial pattern of "increase in the north and decrease in the south." Specifically, water resources in Northern China increased by approximately 13.16%, while a slight decline occurred in the southern region. National total water use exhibited an overall downward trend, accompanied by shifts in the water use structure. domestic and ecological water use increased notably, with ecological water use rising by 243.8%; meanwhile, industrial and agricultural water use decreased, with agricultural water use declining significantly. The reduction in agricultural water use is attributed mainly to decreased water use per mu in actual irrigated farmland, while the decline in industrial water use is primarily due to reduced water use per 10 000 yuan of industrial added value. The growth in domestic water use is largely driven by population increase, and the substantial rise in ecological water use stems mainly from the implementation of ecological conservation policies. The findings in this study will provide a scientific basis for optimizing water resource allocation and promoting sustainable utilization in the new era.