Abstract: The disasters such as landslides and debris flows,often form large deposit in the river bank,which can exert an influence on the river flow through minishing the riverway.Based on the flume experiment,the streamwise and lateral velocity distributions of steep channel under the impact of deposit body are analyzed herein.The results show that: under the impact of deposit,the flow pattern can be divided into four sections,i.e.the low speed zone upstream,the main flow zone,the backflow zone downstream and the R...