中国极端高温未来情景下的公路暴露度分析

Analysis of Road Exposure on the Context of the Future Scenario of Extremely High Temperature in China

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的中国公路数据,采用极值分布对年最高气温进行拟合,预估2030年和2050年RCP4.5和RCP8.5两种情景下不同重现期的极端高温分布及其变化,分析极端高温下中国公路网暴露度的时空格局,并对不同阈值下的暴露度敏感性进行分析。研究表明: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;②相比于基准时间(2015年),中国公路对极端高温的暴露度无论在何种情景都将增长,且增速随着时间增大;③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;④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,京津冀地区暴露度尤其高。

Based on the experimental data from 20 climate models of the fifth phase of the International Coupling Model Comparison Program(CMIP5) and the China Highway data from OpenStreetMap, the annual maximum temperatures are obtainedzy using the extreme value distribution.The extreme high-temperature distributions and changes in different recurrence periods for RCP4.5 and RCP8.5 scenarios in 2030 and 2050 are got.The extreme high-temperature distributions of different return periods are applied in the analyses of the temporal-spatial patterns of Chinese highway network exposure under extremely high temperatures, and in the analyses of the sensitivity of exposure at different thresholds.Results show that: ①China’s extremely high temperature has a clear upward trend, 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;② 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;③ there are significant differences in highway exposure under different high-temperature impact thresholds;④ the exposed hot-area of the highway will gradually increase from north to south, and gradually change from a few small areas to a large area.The eastern part of the highway exposure is more serious than the western area, and the exposure in the Beijing-Tianjin-Hebei area is high.