永定新河河口风暴潮对其右堤防洪保护区洪水风险影响分析

Analysis on influence from storm surge at estuary of New Yongdinghe River on flood risk of its right levee flood control protectedarea

依托全国重点地区洪水风险图编制工作,以永定新河右堤防洪保护区为研究对象,采用MIKE 21/3 Coupled Model FM软件建立风暴潮模型进行洪水演进计算,分别对防洪保护区内遭遇100年一遇、200年一遇风暴潮情景下的淹没水深、范围、流速、历时等洪水风险要素进行分析,估算了由此产生的居民财产、农林牧渔、工商企业、交通运输、水利设施等方面的直接损失。结果显示,永定新河河口遭遇100年一遇风暴潮时,洪水淹没面积20.69 km^2,其中耕地淹没面积0.41 km^2,居民地淹没面积7.46 km^2,受影响人口2.05万人,受影响GDP达235.13亿元。永定新河河口遭遇200年一遇风暴潮时,洪水淹没面积增加17.79 km^2,耕地淹没面积增加1.66 km^2,居民地淹没面积增加3.77 km^2,受影响人口4.18万人,受影响GDP达630.10亿元。各方案洪水损失估算中,工业产值损失所占比重最大,约占65%,其次是商贸业主营收入,约占24%,其余指标在总损失中所占比例均较小。研究成果能够为区域洪水风险管理、防灾避险预案制定及防洪(潮)调度决策提供技术参考。

Based on the compilation of flood risk map for key regions in China and taking the right levee flood control protected area of New Yongdinghe River as the study case, the flood routing calculation is made with the storm surge model established by MIKE 21/3 Coupled Model FM, and then the flood risk factors, i.e. inundation depth, range, flow rate, duration, etc., un- der the circumstances of the storm surges with the return periods of 100 years and 200 years within the protected area are respec- tively analyzed herein, while the direct losses therefrom in the aspects of residentproperty, agriculture, forestry, animal hus- bandry and fishery, commercial and industrial enterprises, communication and transportation, water conservancy facilities, etc. are estimated as well. The result shows that when the storm surge with the return periods of 100 years occurs at the estuary of New Yongdinghe River, the flood inundated area is to be 20. 69 km^2, in which the inundated area of farmland is 0. 41 km^2, the inundated area of residential land is 7.46 km^2 , the impacted population is 20, 500 and the impacted GDP reaches to 23.513 billion Yuan. When the storm surge with the return periods of 200 years occurs at the estuary of New Yongdinghe River, the flood inundated area is increased by 17.79 km2, in which the inundated area of farmland is increased by 1.66 km^2 , theinundated area of residential land is increased by 3.77 km^2 , the impacted population is 40, 180 and the impacted GDP rea- ches to 60. 010 billion Yuan. Within the estimations of the flood lnsses in all the schemes, the weight of the loss of industrial output is the largest and about 65% and the secondary loss is from the main income of trade and business and about 24% , and the proportions of all the other indexes in the gross loss are less. The study can provide references for the regional flood risk management, the preparation of pre-schmne for disaster-prevention and risk avoiding and the decision-making for flood （tide） control operation.