基于郑州“7·20”特大暴雨移置的山东省傅疃河流域洪水形势分析

Analysis of flood situation in Futuan River Basin based on the transplantation of the“7·20”extreme rainstorm in Zhengzhou City

在气候变化和快速城市化扩张的背景下,我国的极端暴雨洪涝灾害风险呈增加趋势。2021年,河南郑州市“7·20”特大暴雨造成了重大人员伤亡和财产损失,暴露出对特大灾害认识准备不足、防范组织不力、应急处置不当等诸多问题。以山东日照市傅疃河流域为研究对象,采用暴雨移置和洪水模拟的方式,拟定暴雨中心位于傅疃河上游三庄镇和下游日照街道两种方案,基于分布式水文模型和二维水动力模型分析了其在“7·20”特大暴雨情景下的洪水形势,并对比分析了两种方案的洪水过程影响。结果表明,两种方案下流域内的日照水库、马陵水库入库洪峰均超过其历史最大入库洪峰,下游社会经济区整体受灾范围分别为151.96 km2、166.02km2;暴雨中心位于城区时,下游区域平均淹没水深从0.46 m上涨至0.73 m,社会经济区受灾范围增加了9.3%。在现状工程条件下,山东日照市傅疃河流域在遭遇极端暴雨时,将有较大范围的居民聚集区、重要社会机构和基础设施受到洪水的侵袭,因而参考极端暴雨情景分析进行应急预案的编制和汛前演练尤为必要。

Given the context of climate change and rapid urbanization expansion,China is facing an increasing risk of extreme rainstorm and flood disasters.The“7·20”extreme rainstorm disaster in Zhengzhou City of Henan Province,resulted in significant loss of life and property,revealing many problems such as inadequate awareness and preparation for major disasters,weak prevention organizations,and improper emergency response measures.In this paper,the techniques of rainstorm transplantation and flood simulation are employed,and the distributed hydrological model and 2-D hydrodynamic model are utilized to analyze the flood situation in the Futuan River Basin of Rizhao City under the“7·20”extreme rainstorm scenario.The two schemes that the rainstorm center is located in Sanzhuang Town in the upper reaches of the Futuan River and Rizhao street of the downtown area in the lower reaches are proposed.A comparison and analysis of the flood impact of two schemes is provided.According to the findings of this study,both Rizhao Reservoir and Maling Reservoir in the watershed experienced inflow flood peaks that exceeded their historical maximums under the two schemes.The overall disaster area of downstream social-economic zone was 151.96 km2 and 166.02 km2 respectively.When the center of the rainstorm was situated in the urban area,there was an increase in average submerged depth of the downstream area from 0.46 m to 0.73 m,resulting in a rise of 9.3 percent in damage area within the social-economic zone.Under the current engineering conditions,in the event of an extreme rainstorm in the Futuan River of Rizhao City,floods will pose a significant threat to numerous residential areas,critical institutions and infrastructure.Therefore,it is imperative to develop emergency plans and conduct pre-flood drills based on scenario analysis for such extreme rainstorm events.