Wetland zoning in Dongting Lake based on flood conditions

In order to use the Three Gorges Reservoir for the flood control of Dongting Lake and to mitigate its influence on wetlands in the Dongting Lake area, a hydrological model was employed to simulate the flood routing along the Chenglingji River reach.The flood diversion status using three different directions of flood and the discharge requirements of the Jingjiang River after the operation of the Three Gorges Reservoir was also analyzed.The results indicate that improvement of the flood storage capacity in Dongting Lake and protection of the diversion capacity of the three floodways are necessary conditions for flood control safety of the middle reaches of the Yangtze River.Therefore,based on the distribution of towns and industries as well the geographical conditions of the Dongting Lake area,a framework for the wetland zoning of the Dongting Lake area, in step-levels of a central zone with human activities,an expanded flood detention area,a flood detention area and a natural wetland,is put forward.