In order to investigate the impact of sediment deposition at confluence reaches in reservoir areas on the normal operation of reservoir,based on the summaries of existing studies on changes of deposition and erosion at confluence reaches,Baishi Reservoir on Daling River in Liaoning was used as the research object,the influence of different coming sediment,confluence angles and flood feathers at main stream and branches on sedimentation characteristics at different confluence reaches in reservoir areas were explored.Research results showed that under the same condition of coming sediment,confluence angle and probability of flood at main stream and branches,sediment deposition in confluence reaches of perennial reservoirs is much bigger than that of fluctuating backwater area. Sediment deposition in confluence reaches of Mangniu River is relatively bigger in perennial reservoirs of Baishi River,sand bars are formed at longitudinal direction in main stream of confluence reaches. Sand bars development will bring adverse effect to reservoir normal use.
