Observed characteristics of tide-surge interaction along the east coast of India and the head of Bay of Bengal

Hourly tide-gauge data at Chennai, Visakhapatnam and Paradip along the east coast of India and at Hiron Point, at the head of Bay of Bengal, were analysed statistically for tide-surge interaction. Dependency of surge maxima on magnitude and phase of the tide were examined separately and interaction was quantified for each site. Along the east coast of India, interaction is found to be less, but significant. The degree of interaction is highest at Hiron Point, where surges peak more frequently about 4 h before the high tide. Application of a simple model shows the observed surge peak distribution at Hiron Point can be explained in terms of phase alteration of tide due to surge and surge modulation by tide. The degree of interaction tends to increase northward as the tidal range and surge height increases.