Hydrometeorological Drought Characteristics and Their Relationship With SST and Climate Indexes in the Yunnan-Guizhou Plateau, China—Based on the Improved SPERI

Drought is one of the most important meteorological disasters. Many results of meteorological droughts in the Yunnan-Guizhou Plateau (YGP) are currently being studied, and however, fewer results have been integrated to analyze the hydrometeorological droughts. Therefore, the hydrometeorological drought characteristics and their relationships with the sea surface temperature (SST) and climate indexes were studied using the reanalysis dataset and the nonparametric standardized precipitation evapotranspiration runoff index (SPERI). The results showed that: 1) the YGP mainly exhibited drought in annual, winter, and drought seasons, and drought in spring (summer, autumn, and rain seasons) mainly occurred in the west (east). Moreover, the YGP drought was dominated by a decreasing trend; 2) the SPERIs in annual, spring, and drought seasons were positively correlated with longitude, and the other seasons were negatively correlated; 3) except for the spring, winter, and drought seasons, the area of the mild drought in the other time scales, as well as the area of the moderate, severe, and extreme drought at all time scales (except for summer), showed an increasing trend; 4) the drought duration was longer in some regions of the west, the drought severity was stronger in some regions of the southwest, and the drought intensity was higher in some regions of the east; and 5) the regions where the YGP drought area had a significant positive correlation with SSTs were mainly located in the Atlantic, Indian, Western Pacific, and Arctic Ocean. The best relationships with SPERI were the North Atlantic-Eurasia teleconnection and the Central Indian Precipitation.