Practice and reflections on regulating the most extreme low-flow event since 1961 and the most concentrated autumn flood in the Hanjiang River basin

LUO Jinjun; WANG Wei

doi:10.3969/j.issn.1000-1123.2026.01.006

Abstract：In 2025,the Hanjiang River basin exhibited a hydrological pattern characterized by"initial extreme drought followed by abrupt transition to floods".From January to July,the upper reaches of the Hanjiang River experienced persistently below-average rainfall and water inflow,resulting in the most extreme low-flow conditions.After August 25,drought rapidly shifted to flood conditions,and the Hanjiang successively experienced seven numbered flood events in 2025,marking the most concentrated autumn flood season since 1961.Water authorities adhered to an integrated approach to drought and flood prevention and control,fully utilizing the integrated"space-air-ground-water-engineering"monitoring and perception system,the digital twin Yangtze River intelligent flood control and drought mitigation system,and the Hanjiang flood control"four pre"system.Guided by basin-wide coordination and systems thinking,and through coordinated operation of the Yangtze and Hanjiang rivers,joint and unified regulation of water projects was implemented with high precision at the level of"each unit of discharge,each cubic meter of storage,and each centimeter of water level".The flood control,drought relief,and disaster mitigation benefits of key reservoirs and water diversion projects,including the Three Gorges Reservoir,Danjiangkou Reservoir,and the Yangtze-to-Hanjiang Water Diversion Project,were fully realized.With close coordination among relevant provinces(municipalities),government departments,and enterprises,the most extreme low-flow event and the most concentrated autumn floods were effectively managed,ensuring flood control and water supply security.Following dam heightening,the Danjiangkou Reservoir reached its normal impoundment level of 170 m for the third time,marking a comprehensive victory in flood and drought disaster prevention in the Hanjiang River basin in 2025.