Study on lowest ecological water requirement for lakes of taking in & sending out waters:a case study in Poyang Lake Wetland

Poyang Lake located in Jiangxi Province is the largest freshwater lake in China.Poyang Lake wetland ecosystem is a complex,open and interactive system with biodiversity.In recent years,the size of Poyang Lake wetland ecosystem has been decreasing because of a variety of factors.In this paper,from the perspective of ecology and hydrology,we calculate and analyze the water level data with the lake morphology analytic method,and find that the lowest ecological water level of Poyang Lake is 9.37 m,and the lowest ecological water requirement corresponding to the lowest water level is 8.46×108 m3.