Drought assessment in northwest China during 1960-2013 using the standardized precipitation index

摘要

The standardized precipitation index (SPI) can be used to analyze the spatiotemporal characteristics of regional water resources. Monthly precipitation data obtained from 96 weather stations in northwest China from 1960 to 2013 were used to calculate the SPI. Changes in the SPI were analyzed using the Mann-Kendall (MK) test and the Pettitt test. The results indicated that 50 stations had a significant increasing trend in the annual SPI series. Analysis of seasonal SPI trends revealed the prevalence of serious drought conditions in the spring, while most stations exhibited a wetting trend in the winter. Significant (at alpha = 0.05 level) abrupt changes in the annual and seasonal SPI series occurred mostly in 1981-1985. Additionally, a significant abrupt change occurred in the year 1986 in 5 sub-basins (the Turpan-Hami Basin, Gurbantunggut Desert Basin, Northern Tianshan Mountains, Northern Kunlun Mountains, and the Tarim Desert Basin).