基于山坡蓄量动力学模型的中小流域设计洪水计算

The Design Flood Calculation of Small and Medium Watersheds in Sichuan Province Based on Hillslope Storage Dynamics Model

1984年的《暴雨径流查算图表》对我国无实测暴雨洪水资料地区的水利水电工程、道路、桥梁等工程洪水计算起到了关键性作用。现有中小流域设计洪水常用计算方法,如推理公式法、单位线法,其参数物理含义不明确,参数确定往往依赖经验且具有较大的主观性,极大地限制了无暴雨洪水计算手册地区水利水电工程设计。针对上述情况,引入山坡蓄量动力学模型,利用流域关键带结构特征及实测暴雨洪水资料确定模型参数,并将该模型计算洪水成果与洪水频率分析法、推理公式法、单位线法计算成果进行对比,计算结果合理。结果表明,该模型物理机制明确、参数更具有物理意义,可通过少量的野外勘测、室内实验或工程类比来确定参数;将其与流域洪水调查、野外勘测及室内试验等工作相结合,能得到合理的设计洪水计算成果,可推广应用于生产实践。

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.