Comparison of hydrologic models of the flood routing in rivers

Flood routing is a procedure that is used for investigation of variations of the peak, time to peak and duration of the flood hydrograph along open channels. This procedure can be performed using either hydraulics or hydrologic procedures, depend on available data of the river. In the present study, different aspects of hydrologic models that consist of the linear Muskingum, nonlinear Muskingum, Convex, modified Att-Kin and Working-Value procedures were investigated through four benchmark examples and field applications in the Karun River using eight observed flood events. Furthermore, the numerical solution of the Saint-Venant equations by considering all of the terms of the momentum equation as a hydraulics procedure was considered for comparison purpose. The criteria were used for models evaluation, included attenuation of peak discharge (ε), lag of peak discharge (ξ), and mean relative error (E). The results show that the relation between weighted-flow and storage volume that is based on hydraulics and hydrologic characteristics of river reach and its temporary storage is the essential criterion for investigation of the effectiveness of a hydrologic routing procedure. Also, it can be said that, in the conditions of the shortage of the data of the dynamic wave model, the linear and nonlinear Muskingum models are offerable in design projects as best hydrologic models