Response of river-lake hydrologic regimes to local climate change in the Yunnan-Guizhou Plateau region, China

Abstract

Climate change affects hydrological regimes by influencing precipitation and air temperature. The climate change effects on lake hydrology in the Yunnan-Guizhou Plateau of China remain unclear. Lake Dianchi, the Plateau’s largest lake subject to human interference, was selected for the study. Algorithms based on historical meteorological data produced high-resolution climate change scenarios describing climate characteristics at a local watershed scale. Integrated river and lake hydrological models simulated changes in inflow, lake volume, and hydrological extremes under different scenarios. Results showed that Lake Dianchi Basin (LDB) inflow would decrease by 1.88~2.21% if air temperature increased by 1~2 °C but increase by 1.23~16.1% if precipitation increased by 5~20%. Lake volume would change minimally (decrease of 0.87~1.15%) if air temperature increased 1~2 °C and if precipitation increased 5~20% (increase of 0.04~4.12%); thus, the hydrological regimes of LDB are more sensitive to precipitation than air temperature. Changes to 3-day and 7-day maximum hydrological extremes were double those of 3-day and 7-day minimums, indicating precipitation-affected maximum extreme hydrological events during wet season more than minimum extreme hydrological events during dry season. In conclusion, both unevenly distributed precipitation and increasing air temperature will increase wet season floods and dry-season droughts in plateau lakes like Lake Dianchi.