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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS002 Poster presentation 1785
Application of RS and GIS in Tsunami hazards assessment and
Rehabilitation in Car Nicobar Islands
Dr. Arun Kumar
Department of Earth Sciences, Manipur University Associate Professor
Th. Dolendro
The present studies deal with the 26 December 2004 tsunami hazards assessment at Car Nicobar
Island, located at a distance of 200 miles approximately from the epicenter of the Great Indonesian
Earthquake (M9.3). A considerable part of the island has been damaged as a result of the Great
Earthquake triggering and followed by Great Tsunami events. The application of Remote Sensing and
GIS techniques is used to characterize the tsunami damages. The IRS 1D LISS- 3 (Pre) and IRS P-6
(Post) digital data are used to assess the changes in the various coastal features of the island. The
tsunami height, run up elevation, water flow direction, erosion, sand deposition, and coastal subsidence
are main indicators for the main aspects of the damages assessment. The digital image processing of
the pre and post satellite data is carried out, which is supplemented with the detailed field studies at the
island. The digital elevation model (DEM) is generated to demarcate the water inundation, flow direction
and extent of the sea water submergence. 10-15 meters of water inundation on the island is marked
and the flow direction of tsunami water is observed along the NW and SE direction by using 1 meter
DEM. The existing beaches are now extended by 60 meters as sediment deposition on the SW part
while 152.54 meter width of the beach is inundated on its SE part of the island. The new sand
deposition at Kakana and Aukchung beaches are of 2.5 meters high and 10-12 meters wide, which is
observed by comparing the pre and post satellite data. Similarly, the submergence at Malacca beach is
1.25 meters which has caused 170 meters wide stretch of the beach into permanent submergence. This
submergence has also caused the loss of coral at Malacca beach. There are evidences for the earlier
tsunami events based on the study of sand pits at island. The modeling of the tsunami run up and
topography of the island has been attempted. There is good correlation between the tsunami run up,
inundation distance and tsunami height. The application of GIS has been made in demarcating the safer
sites for rehabilitation work in the island. The erstwhile villages on the island were located within the 1
km distance from the sea, therefore, the minimum distance of 1 km has been proposed for
rehabilitation of the villages. The 1 km zone has been used for the plantation by various district level
authorities. The application of remote sensing and GIS is proved to be very useful in assessment of
tsunami hazards as well as rehabilitation measures in the island.
Keywords: tsunami, assessment, rehabilitation