基于CI指数的淮河流域干旱时空特征研究

本文运用淮河流域170个气象台站1961—2010年共50年逐日气温、降水资料以及历史干旱灾情资料，研究CI指数在淮河流域的区域适应性，并以此为基础运用多种统计方法分析淮河流域近50年的干旱时空特征。结果表明：基于CI指数计算得到的历年干旱日数与受灾面积和成灾面积的相关性通过了0.01的显著性水平检验，表明CI指数在淮河流域具有较好的区域适应性。淮河流域年均干旱日数基本呈纬向空间分布，流域北部多于南部；流域东部和西部的干旱日数略有增多趋势，而中部和北部的干旱日数有减少趋势，但均未通过0.05的显著性水平检验；EOF前3个模态累积方差贡献达94.4%，前3个分布型依次为全流域干旱日数一致多或少型、南北相反型以及东西相反型；1961年以来干旱日数共经历了由少到多4个循环交替，目前正处于相对偏少期；M K突变检验表明近50年来淮河流域干旱日数没有明显的突变。

Study on Spatial Temporal Characteristics of Drought in Huaihe River Basin Based on CI Index

By using daily precipitation and temperature data in 170 meteorological stations and historical drought disaster information in the Huaihe River Basin from 1961 to 2010, this paper studies the adaptability of the CI index, and then analyzes the spatial temporal characteristics of drought in the recent 50 years with a variety of statistical methods. The results show that the correlation coefficient between drought days calculated by CI index and drought disasters has past the 0.01 significance level test, indicating that the CI index has good regional adaptability in the Huaihe River Basin. The spatial distribution of the average drought days which descends from north to south is latitudinal. The trend of drought days ascends in the east and west, and descends in the central and north of the basin, but they all have not passed the 0.05 significance level test. The cumulative percent variance of the EOF first three modes reaches 94.4%, the first distribution pattern is consistent within the whole basin, the second is contrary between south and north, and the third is contrary between east and west. The drought days have experienced four circulations since 1961, and now are in the period less than normal. The Mann Kendall mutation test shows that there is no obvious mutation point of drought days in the Huaihe River Basin in the recent 50 years.