Tides in the Gulf of Khambhat, west coast of India

Semi-diurnal tides in the Gulf of Khambhat (Cambay), west coast of India, amplify about threefold from mouth to head. In contrast, the amplification of diurnal tides is much smaller. A one-dimensional barotropic model with channel geometry that is representative of the gulf can reproduce the observed features of amplification. The model is used to determine how amplitude in the channel varies with frequency of forcing at the mouth, and this variation is compared with that seen in channels representative of other better-known embayments. The comparison suggests that resonance, together with geometric effects and friction, sets up the amplification of semi-diurnal tides in the Gulf of Khambhat.