The Design Flood Calculation of Small and Medium Watersheds in Sichuan Province Based on Hillslope Storage Dynamics Model
The"Rainstorm Runoff Calculation Chart"played a crucial role in flood calculation for hydraulic engineerings,roads and bridges in areas of China lacking measured rainstorm and flood data.However,commonly used methods for design flood in small and medium watersheds,such as the empirical formula method and unit hydrograph method,often lack clear physical meaning and rely heavily on subjective experience,which greatly limits the design of hydraulic projects in regions without rainstorm flood calculation manuals.Concerning those situations,we used the hillslope storage dynamics model(HSDM),using key structural characteristics of the watershed and measured rainstorm flood data in Shuangfu watershed in southwestern China to determine model parameters.The flood calculation results were compared with those obtained from flood frequency analysis,empirical formula method,and unit hydrograph method,showing reasonable agreement.The results indicate that the HSDM shows an explicit physical mechanism.The parameters are more physically reasonable,which can be determined through fewer field surveys,laboratory experiments,or engineering analogies.By combining the HSDM with watershed flood surveys,field investigations,and laboratory experiments,it is possible to achieve applicable design flood calculation results,promoting its application in practical production.
small and medium watershedsdesign flood calculationHSDMempirical formula methodunit hydrograph method