随着全球气候变化的加速，交通基础设施如何应对气候变化成为当今世界的前沿性课题。本研究采用国际耦合模式比较计划第五阶段(CMIP5)中 20 个气候模

式的试验数据，以及 OpenStreetMap 的中国公路和铁路数据，预估 2030 年和 2050 年 RCP4.5 和 RCP8.5 两种情景下的极端高温、干旱、极端降水的致灾因子强度、分布及其变化，分析极端高温、干旱、极端降水等多致灾因子下中国公路和铁路暴露度，并对不同阈值下的暴露度敏感性进行分析。研究结果如下：

（1）中国极端高温呈明显上升趋势，2050 年与 2030 年的中国极端高温空间分布差异将大于 2030 年与 2015 年的差异，且 RCP8.5 与 RCP4.5 情景的差异随着时间的增长不断扩大。相比于基准时间（2015 年），中国公路对极端高温的暴露度在何种情景都将增长，且增速随着时间增大。不同高温影响阈值下的公路暴露度具有显著空间分布差异。随着时间增长，公路暴露热点区域范围将由华北向南逐渐扩张，由数个小区域逐渐融合为一个大区域，公路暴露度东部区域较西部区域严重，京津冀地区尤其高。

（2）在干旱条件下，公路和铁路的暴露度与 KBDI 干旱指数的百分位数近似成正比。RCP8.5 情景下的干旱面积远远高于 RCP4.5 情景下的干旱面积，并且二者差距近似随百分位数的增大而减少。受干旱影响的地区面积和公路、铁路的暴露度将随着时间的推移而增加，干旱对基础设施的影响日益显著，特别是在华北、西南和西北地区。今后，我国公路和铁路暴露地区将主要集中在华北和西南地区， 东部地区公路暴露度较西部地区严重，京津冀地区是影响最为严重的区域。

（3）随着降水指数阈值的增加，公路和铁路在极端降水中的暴露度降低。通过对不同降水指数的分析，发现在未来的同一时期，RCP8.5 情景下受极端降水影响的地区以及公路和铁路的暴露度将大大高于 RCP4.5 情景。在 RCP4.5 情景下，2030 年受极端降水影响的地区以及公路和铁路的暴露度低于2020 年，而2050年受极端降水影响的地区以及公路和铁路的暴露度高于 2020 年与 2030 年;在RCP8.5 的情况下，受极端降水影响的区域以及公路和铁路的暴露度会随着时间的推移而增加。未来，中国南方的交通系统将受到更多极端降水的影响。

With the acceleration of global climate changing, how to deal with climate change in transportation infrastructure has become a leading issue in the world. In this study, data from 20 climate models in the Coupled Mode Intercomparison Project 5 (CMIP5), as well as road and rail data from OpenStreetMap in China were used. In this study, the intensity, distribution and changes of extreme heat, drought, extreme rainfall under the two scenarios of RCP4.5 and RCP8.5 in 2030 and 2050 were estimated. This study analyzed the exposure of China's roads and railways to extreme heat, drought, extreme precipitation. The sensitivity of exposure under different thresholds was analyzed. The research results of this paper are as follows:

(1)  China's extremely high temperature has a clear upward trend, and the difference in extreme high-temperature spatial distribution between 2050 and 2030 will be greater than the difference between 2030 and 2015, and the difference between RCP8.5 and RCP4.5 scenarios grow over time; compared with the benchmark time (2015), the exposure of China's highways to extreme temperatures will increase regardless of the scenarios, and the growth rate will increase with time; there are significant differences in highway exposure under different high-temperature impact thresholds; With the growth of time, the hot spots of road exposure will gradually expand from North China to the south and gradually merge into a large region from several small regions. The road exposure in the eastern region is more serious than that in the western region, especially in the Beijing-Tianjin-Hebei region.

(2)  Road and rail exposure under drought is approximately proportional to the quantile of KBDI index. The arid area in the RCP8.5 scenario is much higher than that in the RCP4.5 scenario, and the difference between the two in the lower percentile of the threshold value is greater than the difference in the higher percentile of the threshold value. The difference between them in the low quantile is larger than that in the high quantile. The drought affected areas and road and rail exposure increased over time. The impact of the drought on infrastructure will be increasingly significant, particularly in northern, southwestern and northwestern China. In the future, China's road exposure is mainly in north China and southwest China, and the road exposure in the eastern region is more serious than that in the western region, and the Beijing-Tianjin-Hebei region is the most serious.