五种干旱指数在云南省的适用性分析

Feasibility Study of Five Drought Indices for Use in Yunnan Province

干旱指数是研究干旱的核心和基础,但其计算表达方式多样,并且不同的干旱指数具有一定的使用条件和范围,因此筛选适合云南省干旱监测的干旱指数,对干旱预警及该地区的干旱研究具有重要意义。利用云南省29个气象站点1960年1月—2014年12月降水和气温的月平均资料,在月尺度上计算并对比分析了5种干旱指数在不同地区、不同季节的适用性。结果表明,冬春季,在滇西北和滇东北地区,优先选择SPI;在滇中地区,建议选用SPI和Pa;在滇西南地区,Pa的适用性优于其他4种指数;在滇东南地区,CInew的监测效果较好。夏秋季,除在滇西北地区建议使用SPI外,在其他地区SPEI的适用性更强。SPI对2009年11月—2010年3月冬春连旱干旱演变过程的描述能力略优于其他4种指数。

Drought indices are a critical parameter in drought research, but their calculation varies widely and the validation of every index is limited to certain conditions. In this paper, we analyzed the drought indices suitable for use in Yunnan Province. Five indices were examined, which are Pa, All, SPI, SPEI and CI and their feasibil- ity were analyzed based on precipitation and temperature measured monthly at 29 meteorological stations from anuary 1960 to December 2014 in different regions and seasons across the province. The results showed that in spring and winter, SPI was more suitable for northwest and northeast of the province. In contrast, SPI and Pa worked better for the central province, Pa was more appropriate for southwestern Yunnan, and CI newper formed better in southeast. In summer and autumn, SP1 was more reliable in northwest, while the SPElprovided better re- sults for other four regions. Our test also revealed that SPlpredicted the serious droughts occurring in winters and springs in the province from December 2009 to March 2010 more accurately than other four indices.