Application of Stable Isotope Method in Water Mass Balance of Qinghai Lake

Inflow and outflow contributions to the hydrologic budget of lakes can be determined using a stable isotope mass balance method. It provides a way for integrating the spatial and temporal complexities of the flow field around a lake. In this paper, the method is successfully applied to Qinghai Lake in China. Qinghai Lake located in the northeastern part of the 4,500-metre-high Qinghai-Tibet plateau, is the largest inland lake of China, therefore, it is significant to establish water balance of the lake. According to the stable isotopic value and relevant hydro meteorological data, the mean annual evaporation and groundwater inflow rate calculated for the Qinghai Lake using the isotope mass balance method are 40.9 and 6.40 hundred million stere, respectively, which compare well to measure values, of 40.5 and 6.03 hundred million stere. The results demonstrate that it is feasible for stable isotope mass balance method to estimate inflow and outflow of Qinghai Lake.