基于GIS的长沙市洪涝灾害风险动态评估

Dynamic Assessment of Flood Risk Based on GIS in Changsha City

运用GIS技术的空间分析与建模功能构建洪涝灾害风险评估模型,以长沙市地理基础数据、遥感数据、气象水文、社会统计数据为基础,从洪涝灾害的危险性、暴露性、敏感性三个角度出发,对长沙市洪灾风险进行动态评价。结果表明:与1994年相比,2010年长沙市洪灾敏感性有所增加,暴露性上升,洪灾风险增大;从空间分布上看,长沙市区及望城区由于地势平坦,湘江干流贯穿其中,加之经济发达,因而洪灾风险较高;而西部的宁乡县和东部的浏阳市洪灾风险较低;提出了有针对性的防洪措施。该评价结果与实际情况相符,可为洪灾风险管理与决策提供科学依据。

Mainly using GIS spatial analysis and modeling function of the construction of flood disaster risk assessment model, based on Changsha City geographic data and remote sensing data, weather, hydrology and social statistical data as the foundation, from the risk of flooding, exposure and sensitivity of the three perspective, the authors evaluate the flood risk of Changsha City in 1994 and 2010. Results show that along with the Changsha City urbanization process acceleration, the flooding sensitivity increases, exposure rises, flooding risk increases. Looking from the spatial distribution, as Changsha urban area and Wangcheng County are flat, and Xiangjiang River runs through it, considering the economic development, flood risk is higher; and flood risk is low in Ningxiang County and Liuyang City. Measures of flood control are put forward. The evaluation result accords with the actual situation, and can provide scientific basis for flood risk management and decision-making.