In this study the advantages and importance of a numerical model to predict and monitor the processes governing hydraulic changes alluvial fan river is discussed. For this reason and because of the importance of flow velocity and shear stresses resulting from the erosion of the river, A two-dimensional numerical model to simulate the CCHE2D river changes ranging from Roodan River is used. In this study by the use of large-scale maps of the topography of the area under study Were prepared The model geometry and computational grid with different dimensions, and then measured streamflow characteristics Dimensional hydrodynamic model of moderate depth, implementation and results of the distribution of depth, velocity, specific discharge, shear stress were obtained in the Fan river. The statistical criteria RMSE and MAPE data from the simulation model against observed data, which were Error model for depth with RMSE index Respectively 0. 0851 And MAPE values 5.02 Percentages were calculated. The results showed that the simulated data were compared with data obtained from field measurements are very similar.