Study on Water Balance and Variations in Water Level of Daihai Lake

Daihai Lake is the third largest inland lake and an important wetland nature reserve in Inner Mongolia, which plays an important role in the plateau ecosystem. This paper analyzes the interannual water level of Daihai Lake from 1960 to 2019 and the characteristics of interannual water level variation from 2010 to 2019 in response to its severe situation of continuous decline in water level. And through the water balance model, this paper focuses on the change of lake inflows and outflows from 2010 to 2019, and determines the average multi-year water shortage in Daihai Lake. The results show that the historical water level of Daihai Lake showed a downward trend from 1960 to 2019, and the shrinking ratio reached 62%. In recent five years (2015 to 2019), the shrinking rate was the largest (the decline rate of water level: -0.43m/a; lake shrinking rate: -2.27km
²
/a). From 2010 to 2010, the average water shortage was 25.6779 million m
³
. The research results can provide a scientific theoretical basis for the sustainable development of Daihai Lake.