Efficiency Study of the system dynamics model to simulate the rainfall - runoff (Case Study:Lighvan Watershed)

Limited of water resources and the sustainable management، has made it impossible water supply of all needs، therefore، in order to supply water are required careful planning with high reliability. For this reason، is more than ever before the importance of water management in the catchment basin. In this study used dynamics model (Vensim) and genetic programming to simulate the process of rainfall - runoff in Lighvan Watershd. The genetic programming model was tested to get the best combination of input model. The results show high accuracy Vensim model in the simulation of rainfall - runoff process than genetic programming. The results indicate that Vensim model for most events have a highly significant correlation of genetic programming، also is predicted peak flow and minimum absolute error.