基于典型站点的淮北平原区不同时间尺度下五项干旱指数分析

Analysis of Five Drought Indices in Different Time Scales of Huaibei Plain Based on Typical Station

利用蚌埠气象站1987~2016年的逐日降雨、气温等数据,计算了蚌埠站近30年不同时间尺度下典型的五项干旱指数(Pa、K、Z、SPI、SPEI),分析了年、季、月尺度下五项干旱指数表征的干旱变化特征的差异性,并与实际旱情资料进行对比分析,探讨五项干旱指数适用情况。结果表明,五项干旱指数均能显示区域内干旱的发生,在各尺度上的波动变化大致相同,相关性较好;在年尺度上,皆显示蚌埠地区为典型的3年一旱,K与实际旱情更为相符,其次为SPEI;在季尺度上,Pa、Z、SPI、SPEI计算得到的干旱频率和干旱程度偏低,K显示夏秋冬三季旱灾多发,且形成夏旱的趋势显著;在月尺度上,K表现较好,多发生轻旱和中旱,且每年有4~6个月发生不同程度的干旱事件。

Based on the daily rainfall and temperature data of Bengbu meteorological station during 1987 to 2016,this article calculated five typical drought indices(Pa,K,Z,SPI,SPEI)in different time scales of Bengbu meteorological station,analyzed the differences of drought variation characteristics of the five drought indices on the annual,seasonal and monthly scales.Besides,compared with the actual drought data,the application of the drought indices was discussed.The results show that the five drought indices can reflect the occurrence of drought in this region,the fluctuation changes on each scale are approximately the same,and the correlation of each indices is good.On the annual scale,all indices show that Bengbu is typically one drought in three years.Kindex is more consistent with the actual drought,followed by SPEI.On the seasonal scale,the drought frequency and degree calculated by Pa,K,Z,SPI,SPEIare lower.Kindex shows that there are more droughts in summer,autumn and winter,and the tendency of summer drought is more significant.On the monthly scale,Kindex performs better,light drought and moderate drought occurs frequently.On average,there are 4-6 months of drought events occurred in different level for every year.