Rainfall and drought variability in spatial and temporal context in Lop Nor region, South Xinjiang, China, during 1981–2018

Rainfall is one of the fundamental physical parameters among the climate, which determines the environmental factors as well as the meteorological drought for a particular region. Drought is one of the most important and major natural hazards which might lead to consequences like poverty and hunger. This study analyzes rainfall variability and drought assessment spatially and temporally in the Lop Nor region, South Xinjiang, China, using Standardized Precipitation Index (SPI). For this purpose, various indices such as kurtosis, skewness, and standard deviation were calculated from annual rainfall data (1981–2018) of seven meteorological stations. For trend detection, the Mann-Kendall test was applied to both 12-month and 1-month SPIs. The highest variability was found in Yuli, Ruoqiang, and Tieganlike met-stations. The 12-month SPI results revealed extreme dry periods in the study region from 2007 to 2008, and the moderate drought was observed from 2009 to 2013. The results of the Mann-Kendall trend test for 1-month SPI indicates a more significant trend (positive) in Tieganlike and Ruoqiang, while there are fluctuations in the results of other meteorological stations. In the month of March, almost all the met-stations were found driest as the tau (τ) values were found negative in all stations. The results of 12-month SPI indicate the drying conditions in Yuli and Turpan while the wetting conditions prevailed in the remaining meteorological stations in the region.