Abstarct: Muto carried out experiments at small-scale to determine the effects of sea level rise on sedimentary deltas. The autoretreat theory proposed by Muto. Parker and Muto developed the moving-boundary numerical model to predict the river response to sea level rise baxsed on Muto’s experiments. The model is then modified and adapted for application with large low-slope sand-bed rivers. The numerical model result compared with Shuttle Radar Topographic Mission data. If the rivers flow from highlands onto the lower slopes, bedrock–alluvial transition occurs. The goal is to find the bedrock-alluvial transition point with numerical modeling and to describe the evolution of transition, affected by sea level rise and rising sediment feed. Finite difference scheme is used to solve the equations. At first, the sediment transport relations without bedform are presented. Then the necessary relations for modelling the alluvial domain from bedrock-alluvial transition to the downstream end of the reach are explained. Afterwards, a numerical model to solve these equations is written. To ensure the accuracy of the model, the moving boundary numerical model is checked against experiments. In this thesis, we have tried to improve the assumption to reduce the differences between numerical modelling results from actual results. The actual results obtained from shuttle radar topographic mission data. In previous researches, the dimensionless Chezy friction coefficient, channel-forming shields number at bankfull flow, characteristic median sediment grain size and the average flow velocity at bankfull flow were constant. They are not include the effects of Froude number in the backwater equation. In this thesis، the effect of Froude number in the backwater equation is included and the Chezy friction coefficient in each node is computed. Finally, it was observed that by computing the Chezy friction coefficient by using Keulegen formulation, the differences between numerical modelling results and actual one, has been decreased. In calculations, We applied visual basic programming language in Microsoft Excel in the high tech computer with seven cores.(Core i7)