Water damage phenomenon of spur dike is widespread and influenced by many factors,and the current research results on it is under the condition of constant flow,which can’t be good enough to solve practical problems.Through flume model experiment,under the action of the average daily flow process of natural river,degree of local scour of spur dike was compared respectively with the same return period when maximum flow and flood period as a total annual maximum flood peak discharge and half maximum flood.The results showed that the peak flow plays a leading role in scour depth,the flood volume plays a leading role in scour scope,and effective flood period on the scope and scour depth of the pit are its leading role.Meanwhile,the analysis of the development of scour pit indicated that the range of the scour pit is not increases with time gradually.
