蓄滞洪区洪水演进模拟及堤防溃决损失评估方法

堤防蓄滞洪区的经济社会发展和人口数量增长与防洪矛盾日益凸显,开展蓄滞洪区洪水灾害风险评估研究具有重要的工程价值,风险评估的关键一步是估算堤防溃决损失。为了准确估算堤防溃决造成的生命、经济、生态环境损失,发展了基于MIKE21 FM模型的洪水演进模拟方法,建立了基于蓄滞洪区洪水演进淹没数据的损失评估方法。以鄱阳湖康山大堤蓄滞洪区为例,模拟获得了历史最高水位下蓄滞洪区洪水演进过程,得到了切合工程实际的淹没数据(淹没面积、水深、流速)。在此基础上,划分了灾区内受灾等级,并将洪水演进与损失计算有机结合估算得到了蓄滞洪区的生命、经济和生态环境损失。研究成果为堤防溃决风险定量评估奠定基础,为蓄滞洪区防汛抢险决策方案的制定提供有效参考依据。

Flood evolution simulation in flood storage and detention area and evaluation methods for the dike-break losses

The contradiction between the development and population growth in flood storage and detention areas of the dikes has become increasingly prominent. It is thus of great value to conduct quantitative risk assessment of flood disaster for these areas, and a crucial step for risk assessment of flood disaster is to estimate the consequences induced by dike-break. To accurately estimate the losses of life, economy and ecological environment caused by dike-break, this paper developed an approach for modeling evolution process of flood based on MIKE21 FM model. The methods for evaluating the losses based on the inundated data from the evolution process of flood in the dike storage and detention area were presented. The flood storage and detention area of Kangshan Dike in Poyang Lake was taken as a typical case to simulate the evolution process of flood under the historical highest water level. The actual inundated data including inundated area, water depth and flow velocity of this project was obtained; based on which, the disaster grades in the disaster area were defined. The losses of life, economy and ecological environment in the flood storage and detention areas were estimated by combining the flood evolution with the losses calculation. The research results can lay a foundation for quantitative assessment of the dike-break risk and provide an effective reference for formulating flood prevention and rescue decision-making schemes for the flood storage and detention areas.