The effects of evaporation and precipitation on droughts under global change

Drought can be defined as a kind of natural disaster, with a series of effects in different aspects of human life, including environment, economic, ecosystem and agriculture. Previous studies has delved more deeply into the impact of drought, examining it through a range of drought indices, including PEI, SPEI, PDSI, and others. Our study is aims to analyze and research the effects of evaporation and precipitation on droughts under global climate change. Through the temperature changing data research the global climate change feature, analyzing the development of droughts using a drought assessment index (P-E) and making use of bucket model to analyze the relationship between precipitation rate and soil moisture. Research found that the average land temperature is increasing. On the context of this change, the change of evaporation and precipitation causes dry regions to become drier and wet regions wetter. Furthermore, the 20% decrease of precipitation leads to about a one-fifth decline in soil water content, and a lower precipitation rate would speed up the drought states. Meanwhile, soil moisture can also lead to an increase in precipitation. A coupling phenomenon between precipitation rate and soil moisture is exist. This study provides a new point for predicting future droughts conditions.