Flood Routing Using Numerical Methods: A Review

Abstract

Many water resource management problems require river flow projections. For river flow analysis, the partial differential equations of continuity and momentum, defining free surface flow in open channels were presented by French engineer Saint–Venant. Because these equations are quite nonlinear, they have no analytical solutions. These equations can be solved for flood routing by numerical methods which consist of wave models and numerical models. The numerical model consists of two methods: the finite difference method and the characteristic method. This paper aims on comparative study of the various numerical models based on the works done previously on the flood routing numerical modelling. The numerical methods available to solve these equations for river discharge calculations are reviewed in this literature. The findings from various literatures show that the finite difference method is more accurate than the characteristic method, and larger mesh size can be handled more efficiently by the finite difference models. On further investigation of the finite difference models, the explicit simplified dynamic model yields similar outflow hydrograph characteristics as the other models under the same conditions. Furthermore, it is found that the simplified dynamic model is easier to formulate and simpler to calculate than the other ones. Newer numerical models were also studied, and the lack of use of artificial intelligence in flood routing was a critical review of this study.