A Method for Calculating Minimum Ecological Water Level Considering Hydrological Connectivity of Lake Baiyangdian, North of China

The minimum ecological water level is an important indicator for maintaining the stability of the pattern and function in lake ecosystems. In this study, a method for calculating the minimum ecological water level of the lake was proposed, with the aim of maintaining reasonable hydrological connectivity of Lake Baiyangdian, North of China. Using ten Landsat images the water boundaries and fine water patches were identified within different observed lake levels. Then the corresponding lake hydrological connectivities under various water level cases were then evaluated with the connectivity indices method. Through analyzing the relationship of connectivity variations with water levels, the minimum ecological water level was obtained as the breakpoint of the lake level-connectivity curve. This research proposed a new method for the determination of minimum ecological water level from the perspective of interrelation between landscape patterns and water level change processes, and can provide a decision basis for the replenishment management of the lake.