Abstract. This paper presents a new coupling model to simulate water flow, sediment transport and bed evolution based on the shallow water assumption, depth-average integration as well as the morphological evolution (Chinese Academy of Sciences flow-erosion model, CASFE). The model takes account of the effects of rainfall, entrainment and deposition on the motion of water–sediment mixtures. Limitations and drawbacks of other authors' models are pointed out according to the comparison among these models. The finite volume method has been adopted to solve the one-dimensional dam-break problem considering an erodible bed. Numerical results indicate that the model can adequately describe the complex dynamic problems. Simulation results demonstrate that the entrainment and deposition significantly affects the flow dynamics and morphological evolution.