Abstract：With the continuous decrease of the incoming water and sediment, water disasters in the Lower Yellow River is becoming more and more serious, such as "serious disaster caused by small flood", "cross flow" and "gradient flow". To reveal the causes of these phenomena, an analysis on the responses of the channel to the variation of water and sediment processes in the Lower Yellow River is performed. The typical stations of Huanyuankou and Jiahetan in the Lower Yellow River are selected in the case study. The results show that as the amount of the water discharge and sediment in the Lower Yellow River decreases, the lower riverbed is deposited, the bed level rises, the channel becomes narrow, and the river pattern is changed. As a result, the risk of water disaster in the lower reaches increases. On the other hand, the changes of the river pattern lead to a failure of proper functions of some river engineering structures and even lead to negative functions of these structures, which could also be the cause of water disasters. The rules would be helpful for decision-making in the river, and the further study is necessary.
2010, Vol. 28 
