Mudbanks of the Southwest Coast of India. V: Wave Attenuation

Abstract

Wave attenuation over mudbanks off the southwest coast of India is examined by considering the mechanics of interaction between progressive water waves and a dissipative bottom mud represented as a standard solid viscoelastic continuum. Application of the resulting model is first demonstrated by using data from a laboratory flume with a soft clay bed subjected to monochromatic wave forcing. Model simulation is shown to compare favorably with measurements of the wave attenuation coefficient and the horizontal acceleration of the oscillating bed. The equilibrium shape of the mud-water interface is shown to be qualitatively similar to the profile that is believed to occur in the prototype environment. The observed agreement, between measured wave spectra off the city of Alleppey in Kerala State and those simulated by the model, highlights the importance of accurate rheological characterization of mud to account for wave energy dissipation.