Storm surges or tidal waves are the most dangerous aspect of cyclones. Records show that 75 per cent of the loss of life caused by cyclones, is due to storm surges, says retired Director of the India Meteorological Department (IMD) P.V. Rama Rao. All parts of the coast are, however, not equally susceptible to major surges.
The east coast of South Tamil Nadu, coast of Krishna, West and East Godavari districts in Andhra Pradesh, north Odisha coast and the whole of West Bengal coast are most vulnerable to storm surges. “The storm surge height depends upon factors like coastal topography, local bathymetry of the coast and the wind speed associated with the storm. Visakhapatnam is the safest on the entire east coast as its offshore bathymetry (bottom topography) is steep and no storm surge can affect it,” says Mr. Rama Rao who has a made an analysis, post-Hudhud, of three cyclones which had crossed the Visakhapatnam coast.
The second major destructive factor is heavy rains due to cyclonic storms. Heavy and prolonged rains may cause floods and inundate low-lying areas resulting in loss of life and property.
Heavy rains ranging between 30 and 50 cm in 24 hours are common in association with cyclones.
The high winds in severe cyclones may reach very high velocities of 150 to 220 kph or even more. The area across which the eye of storm passes experiences violent winds twice, before and after the passage of the eye. Eye of the storm is observed only in association with severe cyclonic storms.
