呼伦贝尔市新旧综合气象干旱指数应用对比

利用呼伦贝尔市4个气象台站1972—2013年逐日气象观测资料,计算逐日新的综合气象干旱指数MCI与旧的综合气象干旱指数CI,并对比两种干旱指数统计出的干旱日数、干旱强度,以及根据相应标准统计出的干旱过程和与实际干旱发生情况的吻合程度,分析新旧指数的优劣。结果表明,由于CI没有区分逐日降水量在指数中的权重,从而造成其跳变要多于MCI,而且MCI引入了近150天降水量的SPI并区分了冬、夏半年的权重值,避免了干旱指数对呼伦贝尔市冬季、初春干旱评价过重的问题。结合呼伦贝尔市实际的气候特点和干旱灾害发生实况,MCI更符合实际,适合业务应用。

Application of CI and MCI Indexes in Hulunbuir

By using the daily meteorological observation data from 4 stations of Hulunbuir from 1972 to 2013, two kinds of daily comprehensive meteorological drought indexes (MCI and CI) on year on year basis are calculated, and the drought days, drought intensity, drought duration, and typical drought processed, as well as the coincidence degree with actual condition, are calculated and compared by means of the two kinds of drought indexes.The results show that for not considering the weight of daily precipitation, there are more jumps in CI than in MCI; in MCI, the 150 day SPI (Standardized Precipitation Index) is introduced and the weights of the winter and summer precipitation are considered to avoid the overweight problem of the drought index for Hulunbeir winter and early spring droughts. In combination with actual climate and actual situation of drought disasters in Hulunbeir, the results indicate that MCI is closer to the reality and more suitable for practical applications.