Abstract:

Based on the simulations from 17 CMIP5 models and the estimated data of social economy, the risk of rainstorm and flooding disaster under RCP4.5 and RCP8.5 scenarios in China were projected. By the end of the 21st century, increased extreme heavy rainfall with greater intensity and frequency could be found. The risk of rainstorm and flooding disaster would increase with time evolution and significant risk could be observed in 100-year return period under RCP8.5 scenario. Concerning the two return periods in the 21st century, an increase of the GDP exposure could be found under both the two scenarios, while for the POP exposure, continuous growth under RCP8.5 scenarios and growth followed by a decline under RCP4.5 scenarios was reported. For the spatial distribution, higher risk level of flooding hazard was mainly found in central and eastern China. Relative to the reference period, decreased areas of low risk and increased areas of higher risk (the IV and V level) were presented, particularly in high risk (the V level) area. Under the 10-year return period, throughout the 21st century, the IV and V level risk areas would continuously increase under RCP8.5 scenarios, while that under RCP4.5 would present a growth followed by a decline. However, significant increase could be found in the higher risk (the IV and V level) areas for the 100-year return period under both the two scenarios.

Key words: rainstorm and flood, disaster risk, distribution function, return periods

摘要：

利用耦合模式比较计划第5阶段（CMIP5）17个全球气候模式的模拟结果和SSPs社会经济预估数据对RCP4.5和RCP8.5排放情景下中国地区21世纪暴雨洪涝灾害风险的可能变化进行分析。结果表明：21世纪末，极端强降水事件将增加，且极端降水的强度和频率也将增强；暴雨洪涝风险可能随时间呈增加趋势，RCP8.5高排放情景下100 a重现期的洪涝风险更为明显；21世纪RCP4.5和RCP8.5情景下10 a和100 a重现期GDP物理暴露度都将增加；RCP4.5情景下，POP物理暴露度随时间的推移呈先增长后减小趋势，RCP8.5情景下则持续增长。区域分布来看，未来暴雨洪涝风险较高的地区集中在中国中东部及沿海地区，相对于1961—2005年基准期，低风险区面积将缩小，中高以上风险区(IV和V级)面积不断扩大，尤其是高风险区（V级）面积扩大更加明显。21世纪，10 a重现期暴雨洪涝灾害中高以上风险区域（IV和V级）面积在RCP4.5情景下随时间多呈先增加后减小的趋势，在RCP8.5情景下不断增大；100 a重现期中高以上风险区域面积在2个排放情景下都呈不断增加趋势。

关键词: 暴雨洪涝 暴雨洪涝, 灾害风险, 分布函数, 重现期