基于物理基础与基于栅格的分布式水文模型研究

借鉴分布式水文模型CASC2D的研究并结合中国的情况进行改进。为提高模型的计算速度以及增加模型在中国流域的实用价值,在模型中引入Preissmann隐式差分方法来计算河道汇流并与原模型的显式差分方法进行对比;引入蓄满产流模式计算栅格单元的产流并与原模型的Green-Ampt产流模式进行对比;引入线性水库或滞后演算方法来描述湿润地区地下径流的汇流过程。根据Goodwin Creek和舒家实验流域的概况,拟定具体的研究方案,模型在两实验流域都取得了良好的洪水模拟效果,从而验证了模型结构的合理性和正确性。随着地理信息系统和遥感技术的进一步发展,分布式CASC2D模型将广泛应用于中小流域的洪水模拟和预报。

Study on distributed hydrological model of solving physical equation on grids

A hydrological model was developed by adopting Preissmann implicit scheme of channel flow and the ideas of distributed hydrological model CASC2D,and it was compared with explicit finite difference method.In this model,a method of saturation excess runoff that was developed for the Xinanjiang model,is used to calculate runoff process on every grid cell and it was compared with the models solving Green-Ampt equation.To improve CASC2D modeling technique,a linear reservoir method with time lag is used for groundwater runoff routing.Application of this improved model to the Goodwin Creek catchment and the Shujia catchment shows high accuracy of simulation.With fast developing of geographic information systems and remote sensing,distributed hydrological models will be widely applied to simulation of flood for small and medium catchments.