气象干旱综合监测指数在湖北的本地化应用及其适用性分析

在对气象干旱综合监测指数(IMCI)特点理论分析基础上,结合湖北省干旱特点,对IMCI在湖北省应用进行了参数修订。通过与干旱监测业务中使用的综合气象干旱指数(ICI)在干旱统计特征、典型干旱过程诊断能力方面的对比分析,评估了IMCI指数在湖北省的适用性。结果表明:IMCI未改变ICI干旱监测的总体结论,但在干旱演变过程方面较ICI平缓,且对持续时间较长的大旱过程刻画较好。修订后的IMCIHB有效纠正了IMCINCC对旱情发生、发展及缓解过程反应过于迟钝、旱情监测偏重的不足,同时相对于ICINCC2对降水过于敏感又有所改善。然而,IMCINCC和IMCIHB依然存在冬季对微量降水过于敏感及旱情不连续发展的不足。干旱指数在特定区域应用时进行适当的修订和适用性检验是必要的,研究结果可为IMCI在国内其他地区应用的修订提供参考。

Modification and Applicability Evaluation of Comprehensive Monitoring Index of Meteorological Drought in Hubei Province

Based on the theoretical analysis of the characteristics of the comprehensive monitoring index of meteorological drought（IMCI）,together with drought characteristics in Hubei Province,the IMCIproposed by the National Climate Center（NCC）is modified for use in Hubei Province,and then tested in the aspects of the statistic characteristics of droughts and the diagnosis capability of typical drought processes through comparing with the commonly used compound meteorological drought index（ICI）.Results show that there is no significant difference between IMCIand ICIin the general conclusion of drought monitoring, but IMCIshows a slower rate than ICIin drought development,and IMCIperforms better at characterizing long-term severe droughts.In addition,the modified IMCIhas effectively corrected the insensitivity of the NCCIMCIin detecting of the occurrence,development and relief of droughts as well as its overestimate of drought severity,and the modified IMCIis no more too sensitive to precipitation compared to ICI.However, both indexes still tend to too sensitive to small precipitation in winter season and there are unreasonable phenomena：sudden enhancement of droughts in both.The results suggest that it is advisable to perform a proper evaluation and modification if necessary before applying IMCIto a new specific region.