基于HEC-HMS水文模型的流域洪水临界雨量模拟分析

Simulation of watershed flood critical rainfall value using HEC-HMS Hydrological Model

为提高大清河流域拒马河水系紫荆关流域山洪模拟及预报的准确性,推求紫荆关流域临界雨量,以期为流域山洪预报预警提供参考。基于紫荆关流域实测场次暴雨洪水数据及流域下垫面资料,构建了紫荆关流域HEC-HMS水文模型,以不同缩放比例的典型降雨过程为输入,通过大量模型运行计算,推算了流域不同土壤湿度条件下的临界雨量。研究结果表明,构建的流域HEC-HMS模型率定期及验证期的模拟洪峰及洪量的相对误差均在20%以内,能够满足精度要求,HEC-HMS模型可用于紫荆关流域洪水模拟与洪水预警。流域前期土壤湿度条件为影响临界雨量的一个重要因素,不同流域前期土壤湿度条件下,临界雨量也各有不同。研究成果对完善流域山洪灾害预警预报计算方法具有重要的指导意义。

In order to improve the accuracy of mountain torrent simulation and forecast in Zijingguan Basin,the critical rainfall in Zijingguan Basin is inferred,so as to provide reference for mountain torrent forecast and early warning. HEC-HMS hydrological model of Zijingguan Watershed was constructed based on the measured rainstorm flood data and underlying surface data of Zijingguan Basin. With typical rainfall processes of different scaling ratios as input,the critical rainfall values under different soil moisture conditions were calculated by running a large number of models. The results show that the relative errors of simulated flood peak and flood volume in the periodic and verification periods of the HEC-HMS model are all less than 20%,which c meet the accuracy requirements. the HEC-HMS model can be used for flood simulation and flood warning in Zijingguan Basin. Soil moisture condition in the early stage of the basin is an important factor affecting the critical rainfall,and the critical rainfall is also different under different soil moisture conditions in the early stage of the basin. The research results have important guiding significance for improving the calculation method of mountain flood disaster early warning and prediction.