Analysis of Temporal-Spatial Variation Characteristics of Drought: A Case Study from Xinjiang, China

It is of great significance to study the characteristics and change trends of drought in Xinjiang to provide a basis for implementing local strategies. Based on monthly precipitation and temperature data from 95 meteorological stations in Xinjiang, from 1960 to 2018, the Standardized Precipitation Evapotranspiration Index (SPEI) was calculated, and the characteristics and trends of drought in Xinjiang were analysed, in details. Furthermore, a comprehensive evaluation index, i.e., Regional Drought Severity (RDS), was proposed to analyse the effects of duration of the drought and the extent of the drought affected area. The results from our study suggested: (1) In consideration of global warming, droughts in Xinjiang have intensified during the past 59 years, and the frequency and range of droughts have increased significantly; (2) During the plant growing season, spring, summer, and autumn, a drying trend was observed, while, a wetting trend was identified for winter season; (3) The drought-prone months shifted from January and December to March-November in the 1970s, and April was identified as a month with the highest frequency of droughts; (4) The meteorological change occurred a period near 1997. It can be speculated that the intensified droughts can be triggered by the excessive temperature rise, through comparing the changes in SPEI and the Standardized Precipitation Index (SPI), before and after the meteorological change; (5) After the meteorological change, the frequency of droughts with different levels had significantly increased, in addition, the drought-prone areas shifted from the north-west to the south-east. The results from this research provide important support for drought management in Xinjiang, also offer scientific basis for the formulation of relevant policies on agricultural and animal husbandry production.