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

摘要

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 similar to 2.21% if air temperature increased by 1 similar to 2 degrees C but increase by 1.23 similar to 16.1% if precipitation increased by 5 similar to 20%. Lake volume would change minimally (decrease of 0.87 similar to 1.15%) if air temperature increased 1 similar to 2 degrees C and if precipitation increased 5 similar to 20% (increase of 0.04 similar to 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.