中文摘要：

标准化降水指数（Standardized Precipitation Index,SPI）能够直观地表达干旱持续的时间和干旱强度,反映不同地域和不同时间尺度的干旱情况.以SPI作为干旱评价指标,利用辽宁省各气象站1965年1月—2014年12月的逐月降水量数据,结合干旱发生频率和强度频率,分析了辽宁省最近50年的月、季及年际干旱特征.并且利用GIS技术,绘制辽宁省不同强度干旱事件发生频率分布图,探讨各干旱强度的空间分布变化.结果表明：时间变化上,辽宁省干旱事件频繁,主要发生在下半年,常为夏秋连旱,且干旱发生频率随着年代的变迁呈现不断增高的趋势;空间分布上,辽宁省不同强度干旱事件的发生具有明显的地域性,其中以沈阳、本溪、丹东较为严重.研究结果可为相关管理部门因地制宜地制定干旱防御计划提供决策依据,合理安排防灾减灾资源.

英文摘要：

Standardized precipitation index（ SPI） can directly express drought duration and intensity reflect drought situation in different regions and time scales. This study calculated SPIs,the frequencies of drought occurrences and intensities by using monthly rainfall data of meteorological stations in the Liaoning province from 1965 to 2014,and drew the frequency distribution maps of different drought grades by using GIS. The temporal and spatial changes in the 50 years were analyzed. The analysis results showed that,from the time changes of drought,drought in the Liaoning province frequently occurred and mainly in the second half of a year. It was usually from summer to autumn. The frequencies of drought occurrence increased with the times change. From drought spatial distribution features,drought grades distributed regionally in the Liaoning province and the severe drought mainly distributed in Shenyang,Benxi and Dandong. The results of this study can provide government departments a scientific basis for making drought defense strategies based on local conditions to rationalize disaster-reduction resources.