Study Hydrodynamic Regime of the Coastal Area of Thuan An, Hue Using MIKE 21/3FM Model

Abstract

The dynamic regime of the coastal zone in Hue City is strongly influenced by the monsoon, typhoons (tropical storms), and a small tidal range. To investigate the interaction of these factors, this study applied the Mike 21/3FM model after calibrating and validating the wave, current, and water level simulations with observational data. Continuous simulation over a typical year, 2020, showed that meteorological and oceanographic factors caused a maximum sea level rise of up to 1.48 m (due to tides, seasonal variation, and storm surge) combined with large waves exceeding 3 m during the northeast monsoon period (from September to April of the following year). This resulted in a large longshore current, reaching 1.5 m/s, primarily directed from South to North. Conversely, the dynamic is weak during the southwest monsoon period (from May to August). During this time, the seasonal water level variation is lower than the mean sea level, while tidal levels are low, surface wave heights are also low (less than 1 m), and the longshore current velocity - now primarily driven by the tides, is less than 0.25 m/s. This leads to the conclusion that the hydro-oceanographic regime in this area is heavily dominated by atmospheric agents, underscoring the importance of meteorological-climatic conditions in the hydrodynamic of this coastal area.