Alternative Flood Routing Scheme Based on Muskingum Equation

摘要

Muskingum method is one of the tools most frequently used for flood routing in natural channels and rivers for its simplicity. But it is not perfect. One of the disadvantages with Muskingum method is that it assumes a linear relationship between the channel storage and the weighted flow along the river - reach. In this paper an alternative storage equation is introduced. The new storage equation can give the right river — reach storage even if the relationship between channel storage and the weighted flow were nonlinear. The Muskingum equation is modified to adapt for the new storage equation. Based on the new storage equation and the modified Muskingum equation, an alternative flood routing scheme is built. The newly built scheme interprets the meaning of the Muskingum parameter x. Also, it reveals the relationship between x and the effect of leap-edge dip, that is, the greater x is, the more distinct the effect of leap - edge dip will be. On the cognition of the leap - edge dip, another scheme with dip control is built. From a point of view of volume conservation, both of the newly built schemes conserve volume. They have been applied in the Yuanling — Wangjiahe reach of Yuanjiang River, Hunan Province, China. The result shows that the new scheme with dip control is more accurate than CPMC method in practical application.