洞庭湖地区洪水灾害风险评估

摘要

Synthesizing theories and methods of the current domestic and foreign scholars, flood risk is assessed for Dongting Lake region based on the disaster risk system, which is an interaction system of disastercausing factor, hazard inducing environment and hazard bearing body. In the assessment, disaster-causing factor is described by weighted frequency of rainstorm and over, hazard inducing environment is described by topography and drainage density, and vulnerability of hazard bearing body is by inherent vulnerability and disaster response capacity. Assessments on regional flood hazard risk, risk of hazard inducing environment and vulnerability of hazard bearing body are done successively, and overlay analysis on these three factors are done to get a risk zoning map of flood in Dongting Lake region. flood risk along the Yangtze River area, Xiangjiang River and Lishui River near the lake area is the highest, the risk of the surrounding area along the Dongting Lake is higher, and the risk of the edge of Dongting Lake is low.%综合当前国内外学者的理论及方法,以灾害风险系统是致灾因子、孕灾环境和承灾体共同作用的系统为基础,对洞庭湖地区进行洪水灾害风险评估,其中致灾因子用暴雨及以上降雨的加权频次来描述,孕灾环境用地形和河网密度来描述,承灾体脆弱性用内在脆弱性和抗灾救灾能力来描述.首先,对区域洪水致灾因子危险性进行评估;其次,对孕灾环境危险性进行评估;再次,对承灾体脆弱性进行评估;最后,对三者进行叠加分析得出洞庭湖地区洪水灾害风险区划图.其中,沿长江地区、湘江入湖地区和澧水河入湖地区洪水灾害风险高;其次是沿洞庭湖周围地区风险较高;洞庭湖地区边缘风险较低.