基于降雨径流关系的山洪动态临界雨量计算研究

Research on Dynamic Critical Rainfall Calculation of Flash Flood Based on Rainfall-Runoff Relationship

为解决初始土壤含水量不确定性给山洪快速准确预警带来的难题,实现山洪临界雨量的动态计算,以初始土壤含水量、降雨量和径流深之间的指数型关系为基础,构建考虑初始土壤含水量的降雨径流关系,并通过试算法得临界雨量。以陕西省子洲县岔巴沟流域为典型区域,构建同历时降雨初始土壤含水量和临界雨量间的响应关系曲线,用1980—2019年间的21场降雨数据进行验证。结果表明:临界雨量计算准确率为85.7%,因此基于降雨径流关系的山洪动态临界雨量计算方法具有一定可行性。

To solve the problem of uncertainty in the initial soil moisture content in rapid and accurate flash flood early warning and achieve the dynamic calculation of the critical rainfall,this paper took the exponential relationship between the initial amount of soil water,rainfall,and runoff depth as the basis for determining flow production.The rainfall runoff relationship was con‐structed by considering the initial soil water content,and the critical amount of rainfall was inferred.Taking the Chabagou water‐shed in Zizhou County,Shaanxi Province as a typical area,the paper constructed response relationship curves of the initial amount of soil water and the critical amount of rainfall with rainfall records.The relationship was verified using 21 rainfall data points from 1980 to 2019.The results show an accuracy of 85.7%.Thus,the dynamic critical rainfall calculation method for pre‐dicting a flash flood based on the rainfall-runoff relationship could be feasible.