Realistic Simulation of Instantaneous Nearshore Water Levels During Typhoons

Abstract

3D hydrodynamic simulations were performed on an area extending 600 km off Taiwan island for the period running from September 2011 to December 2012. We covered a winter Monsoon season and a summer season with 17 typhoons recorded. By comparing simulations and measurements during the TALIM typhoon, our model reproduces correctly the storm surge observed along the Wan-Tzu-Liao sand barrier (South-West Taiwan). By a modelling approach, we analyzed the regional hydrodynamic mechanisms which control the sea surface elevation at the Chung-Chin harbour. Tide is the dominant forcing of the water level with more than 1 meter above the mean sea level. Global currents contribute up to 80 cm to the water level but during the SAOLA typhon, the elevation reached 1 meter. The contribution of atmospheric forcings is lower but it can generate 30 cm of elevation (e.g. during GUCHOL and TALIM typhoons).

Using the two-way nesting technique AGRIF with MARS3D V11.2 to improve hydrodynamics and estimate environmental indicators

“…A first strategy relies on unstructured grids together with finite volume or finite element discretizations; numerous models such as Delft3D (Roelvink and van Banning, 1995), SLIM (Delandmeter et al, 2018), TELEMAC-3D (Janin et al, 1993) or T-UGOm (Piton et al, 2020) have shown their capability to cope with complex geometrical features such as river deltas or continental slope for years. A second strategy is based on curvilinear, either orthogonal (Rétif et al, 2014;Diaz et al, 2020;Marsaleix et al, 2006; among many others) or nonorthogonal (Grasso et al, 2018), grids. However, the design of such grids might be a great deal of work and have a lack of flexibility.…”