Future Projection of Rainstorm and Flood Disaster Risk in Sichuan-Chongqing Region under CMIP6 Different Climate Change Scenarios

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  • 1. Plateau Atmosphere and Environment Key Laboratory of Sichuan ProvinceSchool of Atmospheric SciencesChengdu University of Information TechnologyChengdu 610225SichuanChina
    2. College of Environmental ScienceChina University of GeosciencesWuhan),Wuhan 430078HubeiChina
    3. Shihezi Meteorological Bureau of XinjiangWulanwusu Ecology and Agrometeorology Observation and Research Station of XinjiangShihezi 832100XinjiangChina

Online published: 2024-11-29

Abstract

In recent yearsrapid 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 areabut also significantly increase the pressure on urban infrastructure and threaten the safety of people's lives and property. Thereforeit 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 regionprecipitation data from 5 CMIP6 modelsgridded population and economic data under Shared Socioeconomic PathwaysSSPs),as well as DEM and land use remote sensing data. Firstlyusing Tay‐ lor diagramsquantitative indicesS),and standardized anomaly sequencesthe study evaluated the simulation performance of 5 individual CMIP6 modelsan equal-weighted aggregation of 5 modelsEWA-5),and unequally-weighted aggregations of 5 modelsUEWA-5for five selected extreme precipitation indices. Thenby building a comprehensive risk assessment model of rainstorm and flood disaster based on disaster risk and vulnerability of disaster bearing bodythe study conducted risk assessmentsfuture projectionsand comparative analyses of rainstorm and flood disasters during baseline1995-2014and future near-term2025-2044and long-term 2045-2064periods under three different climate change scenariosSSP1-2. 6SSP2-4. 5SSP5-8. 5. Results indicated:(1The EC-Earth3 model performed best in simulating the five extreme precipitation indiceswith correlation coefficients between simulated and observed values of 0. 78 for R95p0. 90 for RX1dayand 0. 77 for RX5day. Overallthe simulation performance of UEWA-5 exceeded that of EWA-5.2During the baseline periodcentral Sichuan exhibited high values for the five extreme precipitation indicesfollowed by eastern Sichuan and Chongqingwhile western Sichuan showed lower values. The year 1998 recorded peak values for all five indiceswith a maximum single-day precipitation of 86 mm for RX1day and an intensitySDIIvalue of 11. 3 mm·d-1.3In future periodsthe 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 periodsvalues of the indices are larger in the long termnotably with R95p averaging 846. 8 mman increase of 169. 2 mm compared to the near term.4During historical periodsareas with higher comprehensive risk of rainstorm and flood disasters were concentrated in central Sichuan and downtown Chongqing. In the two future periodsthe high and moderately high-risk areas in central Sichuan are expected to expandwhile the moderaterisk areas will shrink. The range of low-risk areas in the western Sichuan Plateau will also decreaseand 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 periodsthe range of moderately high and moderate-risk areas in central Sichuan is expected to expandwhile 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 forcingespecially in the western Sichuan Plateau and northeastern Sichuanwhere changes in disaster risk levels are mini‐ mal. The study results can provide important references for reducing disaster risksenhancing emergency response capabilitiesand making scientifically informed decisions for disaster prevention in the Sichuan-Chongqing region.

Cite this article

YAO Ying, LI Xiehui, WANG Lei, LI Hongying . Future Projection of Rainstorm and Flood Disaster Risk in Sichuan-Chongqing Region under CMIP6 Different Climate Change Scenarios[J]. Plateau Meteorology, 0 : 1 . DOI: 10.7522/j.issn.1000-0534.2024.00108

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