Computation of nearshore wave set-up due to wind waves generated by tropical cyclones landfalling in Sri Lanka

The hazard to coastal communities from a landfalling tropical cyclone includes high winds causing damage as well as coastal flooding caused by the storm surge. Of the four physical processes that contribute to the total surge, i.e., the wind set-up, the wave set-up, the tide and the barometric effect, this paper is concerned with the contribution from the wave set-up induced by cyclone-generated waves breaking near the shore. Accordingly, a series of numerical experiments have been performed using a spectral wind wave model to examine and quantify the wave-set-up over a range of tropical cyclone wind speeds and at five coastal locations representative of the different coastal sectors of Sri Lanka. The numerical results have also been employed to test the accuracy and reliability of the wave set-up estimated from three of the analytical formulae available in the literature.