Comparative Analysis of Flood Routing Methods

摘要

Given inflow hydrographs were routed downstream using several different techniques. The resulting outflow and stage hydrographs were then compared. The standard for comparison was chosen to be the solution of the one-dimensional Saint-Venant equations. The approximate techniques considered were the zero-inertia equations, kinematic-wave model, and Modified-Puls with optional subdivision of the reach lengths. The effect of floodplains was considered in contrast to channels of simple cross section. Downstream boundary conditions consisted of one of the following: normal-depth stage-discharge relation, broad-crested overflow weir, or free overfall. Dimensionless graphs of hydrography-peak attention and arrival time as computed by the various techniques are presented. The accuracy of the approximate techniques is found to depend on the values of certain dimensionless parameters. This suggests numerical limits on those parameters for application of a particular method.