Analysis of Flood Propagation through Channels and Reservoirs: Implicit Finite Difference Method

Abstract

AbstractThe problem of analyzing floods through channels and reservoir‐channel systems is important in forecasting floods and in testing the effectiveness of flood control measures. The problem has been solved, numerically, by the finite difference method using a digital computer. The direct (explicit) difference scheme necessitates very small time intervals for convergence, and consequently results in lengthy computations which become prohibitive even on a fast computer. The present paper developes, on the other hand, an implicit finite difference scheme, which is unconditionally convergent, so that any time interval, however large, can be used. The method can be used with advantage on the electronic computer as well as on the desk calculator. When applied to a practical problem of flood propagation, the digital computer time was reduced from thirty five hours, as required by the explicit method, to half an hour by the present method.