Complex Response in Channel Adjustment in the Lower Yellow River during the Period of Clear-Water Scour

Based on the data of the Sanmenxia Reservoir during the period of clear-water scour in 1960-1964,the channel adjustment under the conditions of clear-water scour has been dealt with in the paper.The results indicate a marked difference in channel adjustment between the upper and lower reaches of the braided channel (the reach Tiexie to Taohuayu and the reach Taohuayu to Xinzhai).Accordingly,two types of complex response in channel adjustment have been identified:in the reach where the erosional resistance of bank material is strong and the bed material is coarse,the complex response is related with the adjustment of hydraulic parameters;and in the reach where the erosional resistance of bank material is weak and the bed material is fine,the complex response is related with the adjustment of channel morphology.These can be referred for predicting the tendency of channel change after the construction of the Xiaolangdi Reservoir.