基于一维二维耦合模型的衢州城市洪涝演进分析  

Urban flood process analysis with a 1D/2D coupling model: A case study of Quzhou city

作　　者：耿艳芬[1] 郑鑫 柯兴 Geng Yanfen;Zheng Xin;Ke Xing(School of Transportation, Southeast University, Nanjing 210096, China)

机构地区：[1]东南大学交通学院

出　　处：《东南大学学报（自然科学版）》2019年第5期1005-1010,共6页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51979040)

摘　　要：为准确模拟城市洪涝演进,建立一维河网和二维水深平均浅水模型.采用Preissmann隐式差分格式离散圣维南方程,并用三级联解法求解一维河网水系;采用四边形和三角形混合的非结构网格有限体积法离散二维浅水方程,并用Roe格式的近似黎曼解法求解界面通量.模型采用衢州市2011年的实测洪涝淹没事件进行验证,验证结果显示模型具有较好的模拟效果.用该模型模拟4种不同重现期降雨量下的衢州市城区淹没情况,结果显示城区极端淹没深度超过3m,但超过95%区域淹没深度小于0.5m.此外,不同深度的淹没区域演进过程在同一降雨条件下呈现不同趋势.该模型能运用于具有复杂地形的沿江河城市洪涝数值模拟,亦能为城市防洪减灾研究和城市防洪规划提供精确数据.To accurately simulate urban flood evolution, a 1D river network and 2D depth-averaged shallow water coupling model with porosity is established. The Preissmann implicit scheme is used to discretize the Saint-Venant equation and the 1D river network is solved by a three-step method. The unstructured-grid finite volume method with quadrilateral and triangle grids is employed to discretize the 2D shallow water equation. The interface flux is solved by the modified Roe-type approximate Riemann method. The model was validated by a historical flood event in Quzhou city in 2011. The computational results are fitted well with measurement results. The coupling model was used to simulate the submergence of Quzhou city under four different rainfall conditions. The results show that the inundation depths of more than 95% of the inundation area are less than 0.5 m while the extreme inundation depth is more than 3 m. In addition, the evolution processes of different submerged depths show different trends under the same rainfall conditions. This study can provide accurate data for urban flood process research and urban flood management. In addition, the hydraulic model can be applied to other cities with complex topography.

关 键 词：耦合模型 二维浅水方程 城市洪涝 演进过程 

分 类 号：TU998.4[建筑科学—市政工程]