Conceptual Watershed Modeling for Direct Runoff Computations

This paper describes a simple, physically-based conceptual model utilizing watershed drainage characteristics for rainfall-runoff simulation. This conceptual physiographic model is essentially based on the work of Najafi (2003), which has led to a model comprising the main tributary subwatersheds and a single main channel subwatershed. The Kinematic Wave (KW) theory is used to describe flow over the subwatershed plans. The dynamic wave theory is applied for channel flow computations to compute the watershed responses at the outlet. The proposed model was tested on a natural watershed where the results could be compared with the results obtained by Najafi (2003). The results show the proposed physiographic model has advantages over the former in terms of mathematical formulation and input data preparation as well as computation time requirements