Influence of Inertial Forces in Shallow Water Equation on Urban Flood Simulation

Abstract

Flood simulation is an important reference for the disaster prevention in urban area In this study a coupled flood model based on shallow water equations is adopted to simulate the one-dimensional sewer flow and two-dimensional overland flow in urban areas simultaneously Different momentum equations including diffusion wave local inertial wave and dynamic wave are employed to discover the influence of inertial forces in overland flow model and sewer flow model The simulation results were compared with a high-intensity rainstorm event that occurred on June 12th in 2012 in Taipei City In the verification of the maximum flood extent the sewer flow models based on diffusion wave perform the worst due to the ignorance of sewer flow inertia in pipes with adverse slopes The models using dynamic wave and local inertial wave show similar results whereas the former performs slightly better in predicting the depth and extent of flooding The convective inertial term becomes trivial because the increase in flow cross-sections and the decrease in flow velocity canceling out each other The influence of different momentum considerations in the overland flow model is insignificant on flood extents in comparison with those in the sewer flow model because The results show that the simplification of momentum equations in sewer flow model has a negative influence on flood simulation accuracy

Date of Award	2019
Original language	English
Supervisor	Jiun-Huei Jang (Supervisor)