基于CMIP6的全球及干旱带干旱时空演变

针对全球范围内极端气候事件频繁发生的问题,采用等距离分位数方法,构建CMIP6模式高精度降水、气温数据库,耦合帕默尔干旱指数(PDSI)预估未来情景(SSP1-2.6、SSP2-4.5、SSP3-7.0、SSP5-8.5)下全球及干旱带干旱特征时空演变趋势。结果表明:经过偏差校正的CMIP6模拟精度明显提高;基准期(1979—2014年)全球干旱频次变化较小,干旱历时较长,干旱烈度较强,干旱带的干旱烈度较弱;预测期(2025—2060年)全球干旱特征在时空分布上差异性显著,干旱频次较高,平均干旱历时增加,平均干旱烈度增强;预测期干旱带干旱频次、干旱历时和干旱烈度均呈现增加趋势,热带/亚热带干旱带和温带干旱带变旱趋势较显著。

Spatiotemporal evolution of global and arid zone drought based on CMIP6

In view of the frequent occurrence of extreme weather events in the world, the isometric quantile method was adopted to build the high-precision precipitation and temperature database of CMIP6. Coupled with Palmer drought index (PDSI), the spatiotemporal evolution of global and arid zone drought characteristics under future scenarios (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5) was estimated. The results show that the simulation accuracy of CMIP6 with bias correction is significantly improved. In the base period (1979-2014), the global drought frequency changes slightly, the global drought duration and drought intensity are relatively strong, and the drought intensity in the arid zone is relatively weak. During the forecast period (2025-2060), the global drought characteristics have significant differences in spatio-temporal distribution, with higher drought frequency, increased average drought duration and increased average drought intensity. In the forecast period, the frequency, duration and intensity of drought in the arid zone will increase, and the trend of drought in the tropical/subtropical arid zone and the temperate arid zone will become more obvious.