基于标准化降水指数的内蒙古地区干旱时空变化特征

Temporal and Spatial Variation Characteristics of Drought in Inner Mongolia Based on Standardized Precipitation Index

利用内蒙古及周边地区70个气象站1951~2014年降水数据,采用标准化降水指数等方法,对内蒙古近64年气候干旱时空变化进行分析。结果表明:研究区近64年来除西部年际、春、秋、冬季,中部春、秋季及东部春、冬季气候趋于湿润外,其他均趋于干旱。中、东部年际、植(作)物生长期SPI在2001年和1990年左右发生突变,东部突变后趋于干旱并在2006年左右又发生明显转折后趋于湿润。西部在1960s干旱严重,中、东部在1990s至2000s干旱严重。西部年际SPI由西北向东南、东部由南向北干旱趋势速率呈阶梯状下降,中部干旱趋势速率较西、东部快;植(作)物生长期SPI空间变化与年际一致,但西、中部干旱趋势明显的区域有所扩大。

This paper used Standard Precipitation Index （SPI） to analyze the temporal and spatial characteristics of climate drought in Inner Mongolia in recent 64 years, according to the precipitation data from the 70 meteorology stations during 1951-2014. The results show： In the recent 64 years, there was a humid trend in western part in spring, autumn and winter, a humid trend in the central part in spring and autumn, and a humid trend in the eastem part in spring and winter while there was a drought trend in the other areas; In the central and eastern parts, the abrupt of plant growth period occurred in 2001 and 1990. After that, there was a drought trend in the eastern part which turned to humid in 2006. There was a severe drought in the western part during 1960s, a severe drought in the central and eastern parts from 1990s to 2000s. The annual SPI showed a downward trend of drought rate from the northwest to southeast in the western part, and it was from the south to north in the western part. The trend of the drought rate in central part was bigger than those in the westem and eastern parts. The spatial variation of SPI during plant growing period had a consistency with the interannual variation, but the areas of drought in the western and central parts were expanding.