贵阳旱涝气候变化特征及其趋势分析

利用贵阳近500年(1470~2008年)旱涝等级资料,对贵阳旱涝展开气候变化特征及趋势分析。结果表明:近58年,贵阳出现极端旱、偏旱的频次明显高于过去近500年的平均状况;汛期出现偏旱和旱的次数明显增多,旱重于涝的趋势非常明显。从年代际和百年际尺度看,210年周期是贵阳旱涝振荡的主周期,而50年周期是次周期,且20世纪80年代的干旱程度高于历史上任何一个年代;从年际和年代际尺度上,24年周期是贵阳旱涝振荡的主周期,而7年周期是次周期。借助IPCC AR4最新的模式预估数据集,预估贵阳2011~2020年夏季降水处于旱涝交替频发期,且从本世纪20年代初至40年代中期将处于少雨阶段,可能会出现较长时期的干旱期。

Characteristics of the climate change in Guiyang dryness and wetness and rainfall trends in summer

Use the data of the drought and flood grades for five hundred years in Guiyang,characteristics of the climate change in Guiyang dryness and wetness and rainfall trends in summer were analyzed.The results showed that the frequencies of Guiyang appeared extreme drought and more drought in recent 58 years more than the mean value of recent 500 years. In flood season the frequencies of drought increased obviously and the drought more severe than flood. For the decadal and hundred decadal scales,210-year cycle is the main period of drought and flood oscillation and the 50-year cycle is the secondary. The 20 century and 80 years had the most server drought. For the inter-annual and decadal,24 years cycle is the main period of drought and flood oscillation and the 7 years cycle is the secondary. With the results of the model of IPCC AR4,the drought and flood will happen high frequency in the future 10 years flood seasons,there are less precipitation and the drought will last long period in the 40 years of the 21 st century.