Analyzing the impact of different forms of precipitation (rain and snow) on drought

Precipitation is a key driving factor of drought. This study advanced the first investigation of the impact of different forms of precipitation on drought. This study used the gridded dataset of different forms of precipitation (snow, sleet, and rain) and terrestrial hydrological dataset, with the study period from 1961 to 2015. The standardized precipitation index (SPI) and the standardized runoff index (SRI) were employed to monitor meteorological drought and hydrological drought, respectively. The SPI calculated based on rainfall, precipitation, and snowfall was defined as SPIp, SPIr, and SPIn, respectively. Run theory was used to identify drought events. The drought propagation time and degree was estimated based on the maximum Pearson correlation coefficient method. The results showed that (1) the annual snowfall amounts were higher in the Qinghai–Tibetan Plateau (QTP) and the temperate humid and sub-humid northeast China (THSN). The Southeast Basin and the Pearl River Basin showed a higher runoff amount and an increasing trend. (2) The meteorological drought events of rainfall presented obviously higher severity and duration than the precipitation in northern China and QTP. The hydrological drought event exhibited relatively high severity and duration in THSN and QTP. (3) The propagation degree and time of SPIr–SRI was higher than that of SPIp–SRI in northeastern China and QTP.

• Impact of precipitation forms on drought: This study examines how different precipitation forms (rain, snow, and sleet) affect drought.

• Precipitation trends: It analyzes precipitation trends across China's climate sub-regions, improving understanding of how regional changes impact drought.

• Drought variations: The research identifies spatial and temporal variations in drought based on precipitation forms.