Abstract:

Observed sea levels and a 2D triply-nested ocean circulation model are used to study the tide-surge interaction along the east coast of Leizhou Peninsula which characterized by extensive mudflat, large tidal range (> 4 m) and complex coastline. Dependency of surge maxima on a particular level and different phase of the tide are respectively investigated using two statistical approaches. Results show that the tide-surge interaction along the east coast of Leizhou Peninsula is significant, and the mode of peak surge occurrence is 3 to 6 hours before and after the nearest high water. A 2D triply-nested ocean circulation is used to quantify tide-surge interaction in the study region and to determine its physical mechanism. The amplitude of tide-surge interaction extracted from model results is most intense in the shallow water region of the Leizhou Bay, with value of 1.1 m during strong typhoon events. Numerical experiments indicate that shallow water effect is the main contributor to tide-surge interaction, followed by nonlinear bottom friction, while the contribution of nonlinear advective effect can be neglected. Along the east coast of Leizhou Peninsula, the shallow water effect and nonlinear bottom friction intensify the tide-surge modulation, make the surge peaks occurs more frequently on the rising tide and the falling tide.