“…The fifth assessment report of the Intergovernmental Panel on climate change (IPCC) pointed out that under the stress of global warming, the frequency and intensity of extreme weather and climate events, such as drought and extreme high temperature, are increasing in the global scope (Bai et al, 2020;Guo et al,2020c). In recent 50 years, the annual average surface temperature warming in China is about 1.1℃, and the warming rate is close to 0.22℃/(10 a), which is significantly higher than the global or hemispherical average warming rate in the same period (Ren et al, 2005;Shi,2011;Guo et al, 2020d). Drought is the most prominent environmental problem in northern China, while that of southern and eastern parts is also aggravating (Shi, 2009;Liu et al, 2012;Chen et al,2013;Hu et al, 2015).…”