基于RegCM4模式的华北区域未来洪涝灾害风险预估

基于区域气候模式RegCM4东亚地区25 km分辨率气候变化试验模拟结果，在分析华北区域基准期（1986—2005年）洪涝灾害致灾危险度以及人口和GDP承灾体易损度基础上，建立区域灾害风险评估模型；应用建立的模型预估华北区域RCP4.5和RCP8.5两种情景下近期（2020—2035年）、中期（2046—2065年）和远期（2080—2098年）洪涝灾害风险的变化。结果表明：（1）RegCM4对华北区域基准期洪涝灾害危险度评估指标R20mm和Rx5day模拟能力较好，基准期洪涝灾害风险Ⅲ级及以上的区域位于北京、天津、河北南部和东部以及山西南部等地。（2）RCP4.5和RCP8.5情景下，未来三个不同时期区域大部分地区R20mm和Rx5day、洪涝致灾危险度以及风险增加，RCP8.5情景下增加更明显。风险等级Ⅲ级及以上范围在两种情景下均在中期最大。

Projection of Flood Risk over North China based on RegCM4 Regional Climate Model

Based on the RegCM4 simulation in 25km resolution over North China, extreme precipitation indicators (R20mm and Rx5day) during 1986-2005 are selected to building the flood risk assessment model, as well as the exposure in population and gross domestic product (GDP).The change of flood risk during 2020-2035, 2046-2065, and 2080-2098 in RCP4.5 and RCP8.5 scenarios is then projected. The results show that: During 1986-2005, RegCM4 can represent R20mm and Rx5day over North China, and areas above Level III of flood risk are located in Beijing, Tianjin, southern and eastern Hebei, and southern Shanxi according to assessment model. For the RCP4.5 and RCP8.5 experiments, the increased values of R20mm and Rx5day, higher meteorological hazard index and higher flood risks are found in most areas during the future three periods, especially in RCP8.5 scenario; the largest areas above Level III flood risks are in the medium-term for two RCP scenarios.