Flood Preventing and Controlling Influence of Recovering Flood Storages of Dongting Lake

Dongting Lake is well-known for its flood preventing function in the mid-reach of the Yangtze River and its flood storage capacity is very important for the flood control. In practic, to enlarge the flood storage capacity of Dongting Lake is one of the most important flood control measures for the mid-reach of Yangtze River, Therefore, the area of Dongting Lake must be enlarged, which is one of the most important factors that affect the flood storage capacity. On the contrary, the reclamation cuts back the flood storage capacity. Many specialists have done much work about recovering the flood storages. However, it hasn't been studied that different part of Dongting Lake has different effect on flood control. The present paper has given analysis of not only the flood control influence of recovering the flood storages but also the change of the flood-level after retreating the flood storages in the different part of Dongting Lake.It can be concluded that recovering the flood storages can obviously bring down the flood-level of Dongting Lake and the mid-reach of Yangtze River, and that the flood storages nearer Chenglingji play a more important role in bringing down the floodlevel, that recovering the flood storages nearer Chenglingji is more important for flood control.