City-scale hydrodynamic modelling of urban flash floods: the issues of scale and resolution

Abstract

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 km 2 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.

Flash flood simulations for an Egyptian city - mitigation measures and impact of infiltration

“…In the model of El Gouna, infiltration processes are considered with the Green-Ampt model, which is one of the most common physically-based approaches to model the temporal development of infiltration. There exist few studies on coupling a 2D shallow water model with the Green-Ampt model, such as Esteves et al (2000), Singh et al (2015) and Xing et al (2019), which generally show good agreements with analytical solutions or measured data and therefore confirm that these methods are capable to simulate rainfall-runoff processes. Simons et al (2014) already applied the robust shallow water model Hydroinformatics Modeling System (hms) with the Green-Ampt model for infiltration, which is used in the present study.…”

A Systematic Review of Coastal Vulnerability Mapping

“…The scale alignment should be addressed early on in the coastal vulnerability analysis. More accurate hydrodynamic modeling is generally performed only at local scales and coarse spatial resolution due to computational costs and analytical complexity [122]. However, this is slowly changing with the emergence of models applicable at the regional level and higher spatial resolutions [123].…”

Flood-Prepared: A Nowcasting System for Real-Time Impact Adaption to Surface Water Flooding in Cities

“…In order to predict the transient and complex flow hydrodynamics across different flow regimes that may occur during a flood event, HiPIMS solves the governing equations using a Godunov-type finite volume numerical scheme (Liang, 2010;Xia et al, 2017;Xia and Liang, 2018). The numerical scheme has been applied in accurate and stable simulations of rainfall-induced overland flows of urban areas (Xia and Liang, 2018;Xing et al, 2019). In order to substantially improve the computational efficiency for largescale simulations and real-time forecasting, HiPIMS is implemented on multiple GPUs.…”