基于SPI的安徽省1961—2019年干旱演变特征分析

Analysis of drought evolution characteristics in Anhui province from 1961 to 2019 based on SPI

为分析标准化降水指数(SPI)在安徽省干旱监测评估中的适用性,基于SPI从干旱频率、站次比和干旱强度3个方面分析了1961—2019年该地区干旱时空演变特征。结果表明,1961—2019年安徽省各地区干旱频率总体呈南高北低分布,轻旱、中旱、重旱平均频率分别为31.7%、15.7%和6.1%;1961年以来安徽省轻旱以上平均站次比高达31.7%,有15年发生全域性干旱,1978年是干旱发生面积最广的年份,共发生18次全域性春旱、14次全域性夏旱、17次全域性秋旱和16次全域性冬旱;1961年以来安徽省干旱总体以轻旱到中旱为主,且呈微弱下降趋势,最强年份1978年为特旱级别,各季节干旱强度表现为夏旱>秋旱、春旱>冬旱,2011年的春旱、1978年的夏旱、2019年的秋旱和1968年的冬旱是1961年以来各季节性干旱最强年份。SPI可用于安徽省干旱监测评估。

In order to analyze the applicability of standardized precipitation index(SPI)in drought monitoring and evaluation in Anhui province,the temporal and spatial evolution characteristics of drought in 1961—2019 were analyzed based on SPI from three aspects:Drought frequency,station to station ratio and drought intensity.The results showed that the drought frequency in all regions of Anhui province was generally higher in the south than in the north,and the average frequency of light drought,medium drought and heavy drought was 31.7%,15.7%and 6.1%,respectively;Since 1961,the average station to station ratio of light drought in Anhui province had been as high as 31.7%.There had been 15 years of global drought.1978 was the year with the widest drought area,with 18 times of global spring drought,14 times of global summer drought,17 times of global autumn drought and 16 times of global winter drought;Since 1961,the drought in Anhui province had been mainly from light drought to medium drought,with a weak downward trend and the strongest year.The drought intensity of each season was summer drought>autumn drought,spring drought>winter drought in1978.Spring drought in 2011,summer drought in 1978,autumn drought in 2019 and winter drought in 1968 were the strongest years of each season drought since 1961.SPI can be used to evaluate the drought in Anhui province.