东南沿海水库下游地区基于动态模拟的洪涝风险评估

Risk assessment of flood based on dynamic simulation in downstream of reservoirs in coastal area of southeast China

我国东南沿海地区大多为一些中小流域,这些流域上游多建有水库工程,下游则为人口稠密的平原区,流域调蓄能力小,汇流时间短.同时,随着近年来城镇化快速发展,洪涝风险不断加大.因此,迫切需要开展水库下游不同暴雨重现期下的洪涝风险评估研究,以便为防洪决策提供技术支撑.为此,本文利用遥感、GIS、水文水动力学模型等相关技术方法,建立洪涝动态模拟模型来评估洪涝危险性;采用层次分析法和因子叠加法,从洪涝危险性和洪涝易损性两方面开展洪涝风险综合评估分析.研究表明,通过多学科与多技术手段相结合方法,来模拟预测不同暴雨重现期洪水动态淹没过程,再结合相关社会经济属性,可以有效地评估研究区洪涝灾害的风险,从而为水库调度及流域防洪减灾提供有力支撑.

The coastal areas of southeast china are characterized by small watersheds with reservoirs in the upstream and high den- sity of population in the downstream, and these watersheds generally have weak ability of storage and short flow concentration time. At the same time, with the rapid development of urbanization, the risk of flood disaster is increasing. So it is urgent to make a re- search on the risk assessment of flood in downstream of reservoirs with different frequencies of precipitation to provide technology support for decisions on flood prevention and alleviation. Therefore, a flood dynamic simulation model based on remote sensing, GIS, hydrologic and hydraulic model is employed in the hazard risk assessment of flood disaster, as well as analytic hierarchy process and the approach of combining factors are utilized in the comprehensive assessment and analysis of flood risk in views of hazard and vul- nerability of flood disasters. This research shows that this simulation model can forecast the dynamic process of flood inundation with different frequencies of precipitation and make an effective assessment of the risk of flood disaster combined with related socioeconom- ic attributions, so that it can provide strong support for the reservoir dispatching and flood prevention and alleviation.