基于矢量糙率的栅格单元流量分配模型

Grid cell runoff distribution model based on vector roughness

本文认为地表径流在汇流过程中由于流域坡面上地质层理走向、人类耕作活动、天然植被分布等一系列影响使坡面不同方向上具有不同的曼宁糙率系数取值,从而对栅格单元内地表径流向下游各栅格单元的流量分配产生影响,基于这一认识本文提出矢量糙率的概念,并在分析以往模型的基础上,利用一维圣维南运动波方程结合曼宁方程建立了考虑糙率因素的栅格单元间地表径流流向及流量分配模型。经试验流域应用检验,该模型能更精确地模拟降雨径流过程。

Roughness because of the geologi has great effect on velocity of cal lammination, human activity of overland runoff in different directions are not the overland runoff and varies in different directions and vegetation distribution. Thus, the flow velocities same. Moreover, the roughness affects the runoff distribution when a grid cell discharges runoff towards its downstream grid cells. On this theory, the vector roughness was suggested as a new concept in this paper. A new overland runoff distribution model based on vector roughness was derived from 1-D Saint-Venant equation and Manning formula. The new model was used to calculate the flow in an experimental basin. The result indicates that the model can simulate the precipitation-runoff process more precisely than the multi-direction model.