Prediction and assessment of meteorological drought characteristics in China based on a future climate model

Under the background of a warm and humid climate, predicting and evaluating the future pattern of wet and dry change characteristics in watersheds is of great research significance. Based on the Geophysical Fluid Dynamics Laboratory earth system coupling model and GFDL‒ESM2M climate model, which is highly applicable in China, the characteristics of standardized precipitation evapotranspiration index (SPEI) variations in China at annual and monthly scales was assessed based on downscaled climate data under four typical representative concentration pathway scenarios. The results are as follows: (1) In the future, the annual scale meteorological drought trend in China will become more "aridity", and the monthly scale dry and wet changes will be non-uniform. With the increase of carbon dioxide emission concentration, the proportion of regional aridity in China will be increased in the future. (2) The proportion of wetting area will decrease, and extreme weather events are more likely to occur. In the future, the drought duration in China will mainly be 1–4 months. (3) The return period of drought in large areas of the country will be 1–50 years, and the return period in some western regions even exceed 500 years.