According to water level at 9 hydrologic stations of Poyang Lake and Meixi Lake from 2011 to 2012, the water level and exchange relationship between Meixi Lake and Poyang Lake were investigated in 4 stages about fluctuation of water level. Based on Principal Component Analysis, water level of Xiushui station was selected to be representative of Poyang Lake. It was found that the relationship between Meixi Lake and Poyang Lake varied in different stage. In dry season, the water level of Meixi Lake was relatively stable, ranging from 13.5 to 14.5 m, about 3 m above Poyang Lake. When the water level of Meixi Lake was under 15.8 m, no significant correlation relationships were found between Meixi Lake and Poyang Lake, and water exchange with Poyang Lake was weak. However, when the water level was higher than 15.8 m, Meixi Lake and Poyang Lake became a single entity.During the period, the water exchange was obvious and significant linear correlation between the water level of Meixi Lake and Poyang Lake was found. The findings in the study were important to reveal the co-hydrological process and the potential causes of biological diversity of the dish-shaped pits in Poyang Lake.

Poyang Lake; Meixi Lake; water level; water exchange; wetland