High-efficiency calculation method for watershed rainfall-runoff routing using one-dimensional dynamic wave equations

摘要

Efficiency in solving the Saint-Venant equations for watershed rainfall-runoff routing is important in flood hydrology.This paper presents a high-efficiency numerical solution of one-dimensional dynamic wave equations (HEDWE) for watershed rainfall-runoff routing,in which the full momentum equation is written as a quadratic equation with only one unknown variable Q,water depth is derived from the continuity equation using the two-step predictorcorrector method,and the discrete scheme is the explicit upwind scheme.The results of numerical tests showed the HEDWE approach has several major advantages.1) It is a stable numerical method,even for an initially dry area.2) Its computational efficiency is higher than 4.76E+05 times/s.3) It can be used for overland flow,river flow,and combinations thereof.The primary disadvantages of the HEDWE approach are its unsuitability for rapidly varying flow,such as dam-break floods.