Author(s): He Ma
Linked Author(s):
Keywords: Typhoon Storm surge Shallow water model Local time step GPU-acceleration
Abstract: Typhoons are one of the biggest threats to life and property around the world. Severe storms, especially the combined effects of storm surges and heavy precipitation caused by typhoons, threaten urbanized coastal areas. Reliable hydrodynamic modeling of storm surge process requires simulations with high resolution meshes, which leads to a great increase in the computational costs in traditional CPU hydrodynamic models. This article presented a fast numerical simulation model for storm surge using Graphics Processing Unit (GPU) -enhanced and the local time step (LTS) approach based on finite-volume shallow water model, and applied it to simulate storm surge in Macau, China. Atmospheric pressure stress and wind stress are considered in the shallow water equation and the finite volume method is used to solve the governing equation with unstructured triangular mesh; The time step of each computational cell in the present model is set to close to the locally allowable maximum time step instead of setting time steps of a block as the locally minimum value. The results show that the model is capable of capturing both the amplitude and phase of water level changes corresponding to the combination of tide and storm surge; the main pattern of peak values and the arrival times of the flood at most gauge locations during Typhoon. The comparison of sensitivity cases shows the computational efficiency has been greatly improved by LTS approach: the model can simulate in seconds with GPU-acceleration and the increase the speed by 50% with LTS approach.
Year: 2025