Impacting Factors and Changing Tendency of Water Level in Qinghai Lake in Recent 42 Years

The water level in Qinghai Lake has been declining in recent 42 years; correlatively, the precipitation on lake, the mean annual inflow and the evaporation of lake have been decreasing, especially since 1990s. Correlation analysis shows that the inflow, the evaporation and the precipitation amount in the past year have close relation with the water level of Qinghai Lake, by which we establish the model of water level in Qinghai lake to simulate and forecast those close factors. The result shows that the water level in Qinghai lake will still decline in the next decade.