Evaluation the ecological water demand of Dongting Lake based on ecological hydrology during the storage period

This paper is aimed at evaluating the ecological water demand of Dongting Lake in the middle reach of Yangtze River. Since Dongting Lake has evolved into a lake area connected by three waterways: Eastern Dongting Lake, Southern Dongting Lake and Western Dongting Lake, the ecological water level and ecological water demand of different lake areas must be obtained separately. In the Eastern Dongting Lake, we choose Lujiao station as the water level representative station, and choose Yingtian and Yangliutan station as the water level representative station in Southern Dongting Lake, and choose Nanzui and Xiaohezui station as the water level representative station in Western Dongting Lake. The natural water level data is used to obtain the ecological water level in different lake areas of Dongting Lake based on the ecological hydrology method, and then the ecological water demand is obtained through the lake water level-volume relationship curve. The ten-day average minimum ecological water demand of Dongting Lake from September to October is 6.042, 5.294, 4.095, 3.548, 3.139, 2.864 billion m(3). The determination of the minimum ecological water demand of Dongting Lake provides a scientific basis for defining the safety status of the lake ecosystem.