【摘要】 本文基于1980—2018年逐日气象资料计算了PDSI干旱指数与降水Z指数,对2种指数场进行了EOF分析,并与干旱实况进行了比对。结果表明,PDSI指数能很好地表征贵州省的冬、春、秋3个季节的干旱特征,降水Z指数在夏季应用效果较好,贵州省四季旱涝特征具有全区变化一致的特征。4个季节的年代际变化特征明显,仅冬季和秋季呈涝变旱的趋势,其中冬季倾向率达到0.2;夏季的旱情从整体上看还是呈现略有减缓的趋势,但年际变化较大;2011年以后就没有出现过明显的春季旱情,呈现由干变湿的趋势,春旱近些年有所缓解。冬、春、秋季在1980年前后发生突变后干旱化趋势一度在加重,而春季在2016年、秋季在2014年突变后干旱都有减缓的趋势,夏季则相对复杂多次反复后在2014年再次发生突变,干旱化趋势减缓。Z指数与PDSI指数反映出的周期基本一致,冬、春、夏有2～3年的周期,秋季有3～4年周期。更多还原

【Abstract】 Based on the daily meteorological data from 1980 to 2018,this paper calculated the PDSI drought index and the Z index of precipitation,analyzed the EOF of these two index fields and compared with the actual drought situation.The results showed that the PDSI index could well characterize the drought characteristics of the three seasons of winter,spring and autumn in Guizhou Province,the Z index of precipitation had a good application effect in summer,the four seasons of drought and flood in Guizhou Province had the characteristics of consistent changes in the whole region.The characteristics of interdecadal change about the four seasons were obvious,only winter and autumn showed a trend of changing from waterlogging to drought,in which the winter tendency rate reached 0.2.The summer drought situation as a whole was still slightly slowing down,but the interannual change was large.There had been no obvious drought in spring since 2011,and the trend had changed from dry to wet.Spring drought had eased in recent years.The trend of aridity was increasing after the mutation in winter,spring and autumn around 1980,however,the spring drought in2016 and the autumn drought in 2014 showed a trend of slowing down,while in summer it was relatively complex and repeated for many times,and then it changed again in 2014,and the trend of aridity slowed down.The Z index and the PDSI index reflected the same cycle,winter,spring and summer had a cycle of 2-3 years,and autumn had a cycle of 3-4 years.更多还原