Author(s): Yunsong Cui, Qiuhua Liang
Keywords: Urban flood modeling; Hydraulic structures; Shock-capturing scheme; Shallow water equations;
Abstract: Urban flooding as a result of inadequate drainage capacity, failure of flood defences, etc. is usually featured with highly transient hydrodynamics. Reliable and efficient prediction and forecasting of these urban flash floods is still a great technical challenge. Meanwhile, in the urban environments, the flooding hydrodynamics and process may be predominantly influenced by flow-regulating and flood-protection hydraulic infrastructure systems such as sluice-gates, which should be effectively taken into account in an urban flood model. However, direct simulation of hydraulic structures is not a current practice in 2D urban flood modeling. This work aims to develop a robust numerical approach to directly simulate the effects of gate structures in a 2D high-resolution urban flood model. New computational component is developed and fully coupled to a finite volume Godunov-type shock-capturing shallow water equation model to directly simulate the highly transient flood waves through hydraulic structures. Different coupling approaches, e.g. flux and source term coupling, are implemented and compared. The enhanced urban flood modeling tool is tested by reproducing the laboratory experiments of flood routing in a flume with partially open sluice gates, conducted in the hydraulic laboratory at the Zhejiang Institute of Hydraulics and Estuary, China. Numerical results are compared favorably with experimental measurements. Satisfactory results demonstrate that the present modeling approach is able to accurately simulate the flow through hydraulic structures and enhance the predictive capability of the 2D model for urban flood modeling.