The main trough of riverbed was deepened by large discharge of the river while silted near the river mouth because the sand brought by current deposited near the mouth after closing the water gate.

• 经过大流量冲刷,河床主槽加深,但在下游水闸关闭后,水流携带的泥沙在下游沉积,出口附近河床反而出现淤积;