City-scale hydrodynamic modelling of urban flash floods: the issues of scale and resolution
journal contributionposted on 14.01.2019, 11:37 by Yun Xing, Qiuhua LiangQiuhua Liang, Gang Wang, Xiaodong Ming, Xilin Xia
Hydrodynamic models have been widely used in urban flood modelling. Due to the prohibitive computational cost, most of urban flood simulations have been currently carried out at low spatial resolution or in small localised domains, leading to unreliable predictions. With the recent advance in high-performance computing technologies, GPU-accelerated hydrodynamic models are now capable of performing high-resolution simulations at a city scale. This paper presents a multi-GPU hydrodynamic model applied to reproduce a flood event in a 267.4 km2 urbanised domain in Fuzhou, Fujian Province, China. At 2 m resolution, the simulation is completed in nearly real time, demonstrating the efficiency and robustness of the model for high-resolution flood modelling. The model is used to further investigate the effects of varying spatial resolution and using localised domains on the simulation results. It is recommended that urban flood simulations should be performed at resolutions higher than 5 m and localised simulations may introduce unacceptable numerical errors.
This work is funded by the China State Major Project of Water Pollution Control and Management (Grant No. 2017ZX07603-001), the UK NERC funded Flood-PREPARED project (Grant No. NE/P017134/1) and the Science and Technology Plan Project of Zhejiang Province, China (Grant No. 2017F30013).
- Architecture, Building and Civil Engineering