京津冀地区极端降水时空变化特征——基于CMIP6气候模式分析

Spatiotemporal Variation Characteristics of Extreme Precipitation in the Beijing-Tianjin-Hebei Region——A Case Study Based on the CMIP6 Climate Model

研究气候变化和极端气候对保障京津冀地区的粮食安全和社会经济发展具有重要意义。基于CMIP6中的15个气候模式和京津冀地区气象数据,评估了各个气候模式对京津冀地区气候变化的模拟性能,在此基础上对SSP126、SSP245及SSP585情景下京津冀地区极端降水的时空变化特征进行了分析。结果表明:(1)从时间特征来看,SSP126情景下,降水强度与中雨日数变化趋于平缓,大雨日数、极强降水量与强降水量略呈下降趋势;SSP245情景下,中雨日数、大雨日数、极强降水量、强降水量与降水强度均呈上升趋势,京津冀地区极端降水风险在此发展情景下达到最高;SSP585情景下,除中雨日数呈显著上升趋势外,其他极端降水指数变化平缓,降水强度略有上升;(2)从空间特征来看,中雨日数除张家口西北部外,其他区域均处于高值区,峰值位于京津冀地区南部的邢台与邯郸等地。大雨日数、极强降水量、强降水量与最大降水量高值均位于京津冀地区的东北部,中南部相对较低。降水强度较高区域集中分布在京津冀地区的天津、北京、秦皇岛、承德等中北部地区和南部的邯郸与邢台西部山区。

Climate changes and extreme climate research is of great significance for ensuring food security and socio-economic development in the Beijing-Tianjin-Hebei region.Firstly,this paper evaluates the simulation performance of each climate model on the climate changes in the Beijing-Tianjin-Hebei region based on 15 climate models in CMIP6 and meteorological data in the Beijing-Tianjin-Hebei region.Subsequently,the spatiotemporal variation characteristics of extreme precipitation in the Beijing-Tianjin-Hebei region are analyzed under scenarios SSP126,SSP245,and SSP585.The results indicate that:①From the perspective of time characteristics,under the SSP126 scenario,the changes in SDII and R10mm tend to be gentle,while R20mm,R99p,and R95p show a slight downward trend.Under the SSP245 scenario,R10mm,R20mm,R99p,R95p,and SDII all show an upward trend,and the extreme precipitation risk in the Beijing-Tianjin-Hebei region reaches its highest under this development scenario.Under the SSP585 scenario,except for R10mm showing a significant upward trend,the changes in other extreme precipitation indices are gentle,with SDII slightly increasing.②From the perspective of spatial characteristics,except for the northwest of Zhangjiakou,all other areas of R10mm are in high value areas,with the peak located in Xingtai and Handan in the southern part of the Beijing-Tianjin-Hebei region.The high values of R20mm,R99p,R95p,and Rx5 day are all located in the northeast of the Beijing-Tianjin-Hebei region,with relatively low values in the south.The areas with higher SDII are concentrated in the central northern part of the Beijing-Tianjin-Hebei region,including Tianjin,Beijing,Qinhuangdao,and Chengde;In addition,the southern regions of Handan and the western mountainous areas of Xingtai also have larger SDII.