A Study on Countermeasure of Flood Control in Dongting Lake

Since 1949,due to the sediment deposit and land reclamation, the water surface area and storage capacity in Dongting Lake have shrunk by 1 727km 2 and 126×10 8m 3,respectively.The flood level in Dongting Lake is raised over 1m. The cut\|offs in the lower Jingjiang River made a faster shrinkage of the three mouths in Jingjiang reach to Dongting Lake and caused a significant change of the relationship between the Jingjiang River and Dongting Lake. The deposition in the reach from Chenlingji to Loushan raised the water level at Chenlingji, which is the outlet of Dongting Lake to Yangtze River. As a result, the flood level in Dongting Lake becomes higher and the situation of flood control is very serious. It is difficult in the near future to lower the water level in Chenlingji. Therefore the primary ways to control flood in Dongting Lake should return the farmland to the Lake, raise the dike, and dredge the Lake.