Changes in coastal morphology at Kalpakkam, East Coast, India due to 26 December 2004 Sumatra tsunami

The tsunami which struck the east coast of India on 26 December 2004 caused a significant impact at Kalpakkam coast. To study the effect of the tsunami on the coastal environment, high-resolution satellite images of pre (19 November 2004) and post (29 December 2004) data were used. Aerial images of Kalpakkam coast of 28 December 2004 were employed to demarcate precisely the inundation zones and assess the impact in detail on land-use/land-cover features. The area affected by the tsunami is mapped using satellite images. The prominent changes in vegetation pattern, water-logged areas, soil wetness, creek pattern and sand deposition were delineated with the help of visual analysis. The inundation mapping derived from satellite imagery was validated with the help of ground truth data obtained from the field survey on 28 December 2004. The present study shows that at Kalpakkam coast, inundation ranges between 95 and 530 m, and the run-up varies between 3.3 and 7.7 m. The morphological changes along the coast in the form of reappearance of old drainage have been observed. Coastal vegetation such as small shrubs and grasses was either washed away or uprooted. A fair amount of sediments, including traces of monazite sands, were deposited all along the coast.