年度洪涝灾害风险评估方法及综合防范模式研究

China is one of the countries with most serious natural disasters in the world, including many kinds of hazards, wide distribution, high frequency, severe disaster losses. Flood has characteristics with sudden, high uncertainty, severe loss, obvious annual fluctuation, which leads to high cost and difficulties to response. The establishment of methodology of annual flood disaster risk assessment and integrated risk governance paradigm will provide support to solve these problems. This project intends to choose humid area (Jiangxi), semi humid areas (Hebei) and semi-arid area (Gansu) as the typical study areas, to establish the system of annual flood disaster risk assessment methods, comparing with long-term flood disaster risk assessment, and to build the framework to analyze the uncertainties of assessment results due to limited information. Integrated governance paradigms of annual flood disaster risk in three study areas will be constructed to explore the mechanisms of roles of different behavior subjects, disaster periods, disaster scenarios, multiple objective constraints in paradigms, in which experimental grids (county) will be established to verify and improve the paradigms. The project will provide a scientific basis for the capacities improvement and promotion of regional flood disaster risk early warning and integrated governance.

中国是世界上自然灾害最为严重的国家之一，灾害种类多、分布地域广、发生频率高、灾害损失重；洪涝灾害具有突发性强、不确定性大、损失占比高、年度波动剧烈等特征，综合防范成本高、难度大，科学评估年度洪涝灾害风险、优化风险综合防范模式将对解决此问题提供重要支持。本项目拟以湿润地区（江西）、半湿润地区（河北）、半干旱地区（甘肃）为典型区，研究年度洪涝灾害风险评估方法体系，区别于传统的中长期灾害风险评估，并建立有限信息条件下评估结果不确定性分析框架；构建3个典型区年度洪涝灾害风险综合防范模式，揭示多行为主体、多灾害时段、多灾害情景、多目标约束下的防范模式差异性的形成机制，建立实验小区（县级行政区）验证和完善防范模式。本项目将为提升区域年度洪涝灾害风险预警和综合防范能力提供科学依据。

本项目选择湿润地区（江西）、半湿润地区（河北）、半干旱地区（甘肃）为典型区，建成了年度洪涝灾害风险评估与综合防范模式研究数据库，分析了1978-2022年逐年洪涝灾害损失情况，客观反映出洪涝灾害突发性强、损失占比高、年度波动剧烈、不确定性大等特征，发现近年来湿润地区（江西）洪涝灾害损失有所降低，但半湿润地区（河北）、半干旱地区（甘肃）洪涝灾害损失升高的规律。开展了年度洪涝灾害风险评估方法体系研究，建立了集“未来年度汛期降水预测”、“降水与损失分布关系拟合”、“损失超越概率评估”于一体的年度洪涝灾害风险评估技术方法，是对年度自然灾害风险评估方法的新探索。构建了3个典型省份年度洪涝灾害风险综合防范模式，提出了“分区”、“分时”、“分级”洪涝灾害风险防范模式，建议湿润地区洪涝灾害风险防范重点应放在流域性极端洪涝灾害风险上，做好上下游、左右岸洪涝灾害风险防范预案；半干旱地区洪涝灾害风险防范重点应放在气候可能的暖湿化背景下“小灾多发+大灾突发”风险上，落实好本地洪涝灾害风险防范的各项举措，有序开展基层常态化洪涝灾害风险防范意识和能力培训；半湿润地区洪涝灾害风险防范重点要充分结合上述两地区特点，做好流域洪涝灾害和本地区洪涝灾害风险防范工作。