利用国家气候中心收集和整理的8个CMIP5全球气候模式在RCP8.5、RCP4.5和RCP2.6温室气体排放情景下的逐日降水资料,使用泰勒图对2006-2016年数据进行检验,采用模拟效果最好的CCSM4和IPSL-CM5A-MR模式在等权重系数条件下的平均值,计算并分析贵州省2018-2044年、2045-2071年、2072-2098年3个阶段与降水有关的极端天气气候事件指数,即连续干旱日数(CDD)、大于20mm的降水日数(R20mm)、连续5d最大降水量(Rx5day)和简单日降水强度指数(SDII)相对于参照期(1986-2005年)的变化特征。结果表明:在3种情景下,21世纪各个阶段省东部CDD均多于参照期,且排放情景越高,偏多幅度越大,因此,贵州省东部地区未来可能发展的旱情值得关注。在21世纪不同阶段不同情景下,贵州省R20mm、Rx5day和SDII普遍多于参照期,且越到后期,高排放情景下(RCP8.5)增幅越大,中低排放情景下(RCP4.5和RCP2.6)增幅放缓甚至减小。总的来说,全球变暖背景下尤其是高排放情景下贵州省极端降水事件有增加的趋势。
Under three different scenarios of greenhouse gas emission including RCP8.5, 4.5 and 2.5, the daily precipitation data in Guizhou, covering the period of 2006-2016 from 8 CMIP5 models provided by the National Climate Center, were examined in this study by using the Taylor diagrams. The data from two models(CCSM4 and IPSL-CM5A-MR) with the best simulation results were selected to calculate the extreme precipitation indices during three periods of 2018-2044, 2045-2071 and 2072-2098 subsequently. The indices included maximum number of consecutive dry days(CDD), numbers of days with precipitation ≥ 20mm·d-1(R20mm), maximum 5 day precipitation total(Rx5day) and simple daily intensity index(SDII), respectively, in comparison to those during the period 1986-2005. It was indicated that the CDD over the eastern regions grew during the 21 st century under the three RCPs scenarios and the increase was proportional to the emission scenario. This described that more attention should be paid on the potential drought over the eastern Guizhou in future. Besides, the increases in R20 mm, Rx5 day and SDII were also detected in Guizhou during the 21 st century. In the late 21 st century, the increment of the extreme precipitation was more obvious under high emission(RCP8.5) than those under lower emission(RCP4.5 and 2.6). Overall, it was suggested that extreme precipitation events over Guizhou showed an uprising trend with more gas emission, under the background of the global warming.