CMIP6不同气候变化情景下川渝地区暴雨洪涝灾害风险未来预估
网络出版日期: 2024-11-29
基金资助
四川省高校人文社会科学重点研究基地气象灾害预测预警与应急管理研究中心开放重点项目(ZHYJ23-ZD01);成都信息工程大学科技创新能力提升计划项目(KYTD202343)
Future Projection of Rainstorm and Flood Disaster Risk in Sichuan-Chongqing Region under CMIP6 Different Climate Change Scenarios
Online published: 2024-11-29
近年来的快速城市化发展和全球变暖使得川渝地区的暴雨洪涝灾害呈现频发强发态势。这种变化不仅会对该区的生态环境和社会经济造成严重影响,还会显著增加城市基础设施压力,并威胁人民的生命财产安全。因此,科学和准确地分析川渝地区过去和未来暴雨洪涝的灾害风险尤为重要。本文基于优选的川渝地区 50个气象站点日值降水数据、5个 CMIP6模式降水数据、共享社会经济路径 SSPs下的人口和经济格点数据,以及DEM和土地利用遥感数据等,首先通过泰勒图、定量化指标S和标准化距平序列评估了5个CMIP6单模式、5个模式的等权重集合EWA-5(Equal Weighted Agggation)和不同权重集合 UEWA-5(Un-Equal Weighted Agggation)对所选 5 个极端降水指数的模拟性能,然后通过构建基于致灾危险性和承灾体易损度的综合暴雨洪涝灾害风险评估模型,对基准期(1995-2014年)和未来近期(2025-2044年)和远期(2045-2064年)三种不同气候变化情景(SSP1-2. 6,SSP2-4. 5,SSP5-8. 5)下的暴雨洪涝灾害进行了不同时段的风险评估、未来预估和对比分析。结果表明:(1)EC-Earth3模式模拟的5个极端降水指数的效果最好,R95p、RX1day、RX5day 指数模拟和观测的相关系数分别为 0. 78,0. 90,0. 77,整体UEWA-5的模拟性能优于EWA-5。(2)基准期5个极端降水指数在四川中部为高值区,四川东部和重庆次之,川西地区为低值区;5个极端降水指数在1998年都呈现最大值,其中一年中单日最大降水量RX1day达86 mm,降水强度SDII指数值为11. 3 mm·d-1。(3)未来两个时期,5个极端降水指数呈现出中间高,四周低的空间分布特征,社会脆弱性和辐射强迫等级越高,极端降水指数值越大。对比两个时期,远期各极端降水指数值更大,特别是R95p均值为846. 8 mm,比近期增加了169. 2 mm。(4)历史时期,暴雨洪涝灾害较高的综合风险区位于四川中部和重庆市中心,未来两个时期在四川中部的高和中高风险区范围将扩大,中等风险区范围将缩小,川西高原中低风险区范围也将减少,四川南部和川渝东部的风险等级将分别降为中低和低风险区。对比未来两个时期,四川中部的中高和中等风险区范围将扩大,重庆西南部在远期将变为中等风险区,其余区域基本维持原风险等级,而随着社会脆弱性和辐射强迫的升高,川渝地区的灾害风险等级变化不明显,特别是川西高原和四川东北部的灾害风险等级变化较小。研究结果可为减少川渝地区灾害风险,提高应急响应能力,科学决策和防范等提供重要参考。
姚 颖, 李谢辉, 王 磊, 李红英 . CMIP6不同气候变化情景下川渝地区暴雨洪涝灾害风险未来预估 [J]. 高原气象, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2024.00108
In recent years,rapid urbanization and global warming have led to frequent and severe rainstorm and flood disasters in the Sichuan-Chongqing region. This change will not only have a serious impact on the ecological environment and socio-economic development of the area,but also significantly increase the pressure on urban infrastructure and threaten the safety of people's lives and property. Therefore,it is particularly important to scientifically and accurately analyze the disaster risk of rainstorm and flood in Sichuan-Chongqing region in the past and future. This paper utilized daily precipitation data from 50 selected meteorological stations in the Sichuan-Chongqing region,precipitation data from 5 CMIP6 models,gridded population and economic data under Shared Socioeconomic Pathways(SSPs),as well as DEM and land use remote sensing data. Firstly,using Tay‐ lor diagrams,quantitative indices(S),and standardized anomaly sequences,the study evaluated the simulation performance of 5 individual CMIP6 models,an equal-weighted aggregation of 5 models(EWA-5),and unequally-weighted aggregations of 5 models(UEWA-5)for five selected extreme precipitation indices. Then,by building a comprehensive risk assessment model of rainstorm and flood disaster based on disaster risk and vulnerability of disaster bearing body,the study conducted risk assessments,future projections,and comparative analyses of rainstorm and flood disasters during baseline(1995-2014)and future near-term(2025-2044)and long-term (2045-2064)periods under three different climate change scenarios(SSP1-2. 6,SSP2-4. 5,SSP5-8. 5). Results indicated:(1)The EC-Earth3 model performed best in simulating the five extreme precipitation indices,with correlation coefficients between simulated and observed values of 0. 78 for R95p,0. 90 for RX1day,and 0. 77 for RX5day. Overall,the simulation performance of UEWA-5 exceeded that of EWA-5.(2)During the baseline period,central Sichuan exhibited high values for the five extreme precipitation indices,followed by eastern Sichuan and Chongqing,while western Sichuan showed lower values. The year 1998 recorded peak values for all five indices,with a maximum single-day precipitation of 86 mm for RX1day and an intensity(SDII)value of 11. 3 mm·d-1.(3)In future periods,the five extreme precipitation indices display a spatial distribution characterized by higher values in central regions and lower values around the periphery. Higher levels of social vulnerability and radiative forcing correlate with larger values of extreme precipitation indices. Comparing the two future periods,values of the indices are larger in the long term,notably with R95p averaging 846. 8 mm,an increase of 169. 2 mm compared to the near term.(4)During historical periods,areas with higher comprehensive risk of rainstorm and flood disasters were concentrated in central Sichuan and downtown Chongqing. In the two future periods,the high and moderately high-risk areas in central Sichuan are expected to expand,while the moderaterisk areas will shrink. The range of low-risk areas in the western Sichuan Plateau will also decrease,and the risk levels in southern Sichuan and eastern Sichuan-Chongqing border areas will respectively decrease to moderatelow and low-risk zones. Comparing the two future periods,the range of moderately high and moderate-risk areas in central Sichuan is expected to expand,while southwestern Chongqing will transition to a moderate-risk area in the long term. Other regions will generally maintain their original risk levels. Changes in disaster risk levels in the Sichuan-Chongqing region are less pronounced with increasing social vulnerability and radiative forcing,especially in the western Sichuan Plateau and northeastern Sichuan,where changes in disaster risk levels are mini‐ mal. The study results can provide important references for reducing disaster risks,enhancing emergency response capabilities,and making scientifically informed decisions for disaster prevention in the Sichuan-Chongqing region.
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