华东地区干旱灾害时空演化特征研究

针对国内外现有干旱应用研究往往忽略所采用模型与方法对研究结果存在的影响这一研究缺陷。利用我国中东部地区42个气象监测站点1961-2011年的降水资料,选用SPI指数对比分析了1月、3月、6月、12月四个时间尺度下中东部地区代表站点和月份的时空演化特征。结果表明:(1)不同时间尺度下研究区轻、中、重度干旱出现的时间和概率差异较大,无明显变化规律,但在中度干旱代表站点呈现出总体趋势一致的情况;(2)不同时间尺度下研究区各等级干旱空间分异明显,在中度干旱代表月份呈现出随时间尺度扩大的突变特征,在轻度和重度干旱代表月份,均表现为1月时间尺度下各等级干旱范围变化较大,3月、6月和12月时间尺度下几乎零面积干旱的特征。文中研究在证实区域干旱时空演化特征会随着所选SPI指数时间尺度变化而改变的同时,也肯定了在今后干旱应用研究中开展评估方法本身稳定性和适用性分析的必要性与意义。

Spatial-temporal evolution characteristics of drought disaster in East China

Current drought studies usually ignored the influences of selected models and methods on the results accuracy.Therefore,based on the precipitation data from 1961 to 2011 collected from 43 meteorological monitoring sites in the middle-eastern China,we utilized SPI index for comparison of the spatial-temporal evolution characteristics of representatives under 1 month,3 month,6 month,12 month time scale.The results show:(1) At different time scales,the time and probability of drought in various grades varied greatly without specific law,but the overall trend was consistent for the representative site of moderate drought.(2) The spatial distribution of various grades drought in each representative month in the middle-eastern China also varied greatly from the changes of the time scales of SPI,especially for the representative month of moderate drought.However,in the representative months of light and heavy drought,these variations only happened in 1 month scale,while similar 'zero' area drought characteristic appeared in 3 month,6 month,12 month scale.While this study on one hand validated the connections between the spatial-temporal variation characteristics and the scales changes of SPI,on the other hand it was confirmed the necessarity and significance of analyzing the stability and adaption of the assessment method itself in future.