Flood Risk Analysis of Small and Medium Watershed in Hilly Region Based on Hydrodynamic Model and Risk Index System
Small and medium watershed is often located in complex terrain such as mountains and hills,with broken terrain and scattered residential areas.When studying its flood risk,it is difficult to build a global model and the calcula-tion time is long,so it is necessary to optimize the modeling methods.This study takes Jiande City which is located in the hills of western Zhejiang Province as object.The flood factors are obtained by constructing a one-dimensional hydrody-namic model.Combining with the flood risk index system,the key risk points of the region are located,and the key re-gional coupling model is constructed to assess the flood risk.The results show that using the method of finding the weak-link and then constructing key areas model to assess flood risk,the modeling area is reduced by 61%,and the calculation efficiency is improved;The coupled model has high accuracy,the error of peak water level is less than 0.2 m,and the in-undation range is consistent with survey results;The identified weak areas are Meicheng Town,Sanhe Village and Day-ang Town;Meicheng town has the highest flood risk,Sanhe village has the highest proportion of residential areas sub-merged,and Dayang Town has the largest inundated farmland.Flood control and response capabilities in these areas need to be improved.This study has reference value for flood risk analysis in similar areas.
1D and 2D hydrodynamic modelAHP-Entropy weight methodflood risk analysisJiande City
NETL
NSTL
万方数据
