Flood Control Benefits of Hezhuang Reservoir under"24·7"Rainstorm Flood

CHEN Shuo; QI Yunting; MENG Cuicui

doi:10.3969/j.issn.1004-7328.2026.06.009

Abstract：In July 2024,the Sihe River Basin experienced two extreme rainstorm floods,forming two typical regulation scenarios:low initial storage and high initial storage.Taking Hezhuang Reservoir in the Sihe River Basin as the research object,based on measured hydrological data,this paper analyzed the rainfall characteristics,reservoir water level and flow responses,and runoff coefficient variation patterns of the two floods,revealing the flood response mechanism driven by the coupling of initial storage conditions and underlying surface runoff characteristics.Indicators such as peak-shaving rate,flood interception volume,flood regulation reservoir utilization,and flood peak lag time were used to quantitatively evaluate the flood control benefits of the reservoir,and the effectiveness differences between two regulation modes—full-course interception and combined interception and discharge—were compared.The results show that the two floods cumulatively intercepted 36.09 million m³ of water,with an average peak-shaving rate of 85％,and that initial storage is a key factor determining the response intensity and regulation strategy.Hezhuang Reservoir effectively intercepted and reduced flood peaks during consecutive heavy rains,mitigating downstream flood risks and demonstrating significant flood control benefits.The study provides measured evidence and technical reference for continuous flood response analysis,flood regulation optimization,and benefit assessment of reservoirs in hilly areas of northern China.