基于AWTP指数的辽宁省干旱规律时空分析

Analysis on temporal and spatial distributions of drought events in Liaoning province based on AWTP index

利用辽宁省22个气象站点1958-2008年逐日降水量资料,采用降水的平均等待时间(AWTP)指数,分析了辽宁省近51年的干旱时空分布特征。结果表明,从时间变化来看,辽宁省干旱有加剧趋势,在近50年中,1995年干旱程度最强,相当干期值最大,达71天;90年代干旱最严重,平均相当干期达65天;同时辽宁省干旱存在5年左右显著周期;从空间变化来看,辽宁省干旱的发生具有明显的区域性特征,干旱程度由西向东递减,其中辽西地区朝阳市干旱最重,辽东地区丹东市干旱最轻。

This paper analyzes the temporal and spatial distributions of drought events in Liaoning province recent 50 years on the basis of an index of average waiting time for precipitation （ AWTP）, using the daily rainfall data at 22 hydrological stations over this province for the period from 1958 to 2008. This analysis shows that in this period, the primary cycle of significant drought events was roughly five years, and the drought events took an intensification trend showing an equivalent dry period of 71 days long for the longest drought in 1995. The decade 1990s was the most severe with a mean equivalent dry period of as long as 65 days. In spatial distribution of drought, Liaoning was significantly regionalized with a trend of intensification from east to west, Chaoyang in the west was severely intensified, and Dandong in the east slightly intensified.