2D numerical simulation of tidal current in the sea around Naozhou island based on shallow water equation

The tidal current around Naozhou island is simulated with the shallow equation. The governing equations are discretized by a fractional finite element method using a characteristic-Galerkin procedure. In order to maintain the "well-balanced" property, the bottom slope source term was merged into the pressure equation. Moreover, a local bed slope modification technique is employed in drying-wetting interface treatments, the gradient of water depth was modified to ensure momentum conservation. Then the relationship between tidal level and velocity at the boundary was established based on the characteristic theory to ensure the accuracy of simulation. The results show that the tidal current around Naozhou island is the reciprocating-flow. The tidal current near the Donghai island flows along the NE-SW direction, while flows along the NW-SE direction near Leizhou bay.