一种新的干旱预测指标在贵州旱情评价中的应用

为了分析适用于贵州省的干旱判别指标，对月尺度、季尺度、年尺度的标准化降水指数（SPI）、降水成数（Deciles）、干旱侦测指数RDIst进行比较分析。1951~2010年60 a的气象资料和1984~1989年连旱期间资料的分析结果表明：降水系列的分布越均匀，SPI与Deciles的相关关系越好；由于季尺度的RDIst考虑了蒸发因素对干旱的作用，对实际情况的反映最好，优于在我国广泛使用的SPI指标；Deciles对降水的敏感度高，月尺度和季尺度的Deciles指标不适合在贵州地区应用；年尺度的Deciles则最能反映干旱过程在历史系列中的严重程度。

Application of new drought forecast index in drought evaluation of Guizhou Province

To select the most suitable drought forecast index for Guizhou Province,3 monthly-scale,season-scale and year-scale indexes of standard precipitation index(SPI),deciles index(Deciles),reconnaissance drought index(RDIst) are compared and analyzed.The analysis result by the meteorological data from 1951 to 2010 and the data in the continuous drought period from 1984 to 1989 in Guizhou Province shows that the more evenly the precipitation series,the better the correlative relation of SPI and Deciles;the influence of evaporation factor is considered in RDIst in season-scale and it reflects the practical condition most well and is more effective than the universally-used SPI in China;Deciles is sensitive to precipitation and the monthly-scale and season-scale indexes are not suitable in Guizhou Province while the year-scale Deciles is the most suitable for reflecting the severe degree of drought process in historical series.