ASSESSMENT OF THE IMPACT OF THE TSUNAMI OF DECEMBER 26, 2004 ON THE NEAR-SHORE BATHYMETRY OF THE KALPAKKAM COAST, EAST COAST OF INDIA

• Main Authors: P. Sasidhar, C. Anandan
• Format: Article
• Language: English
• Published: Tsunami Society International 2008-01-01
• Series: Science of Tsunami Hazards
• Subjects: Bathymetry; Kalpakkam; GIS TIN; 3D surface; Tsunami impact
• Online Access: http://tsunamisociety.org/274Anandan.pdf

The devastating impact of the December 26, 2004 tsunami on the coast of South India has been well documented. However, only a few studies assessed the tsunami’s impact in the near-shore region. The present study evaluates changes in bathymetry along the near-shore of Kalpakkam before and after the tsunami. Using GIS software, data was extracted from charts to create three-dimensional bathymetric representations of the offshore region before and after the tsunami. Initially, a TIN (Triangulated Irregular Network) surface was created by using Arc GIS software. Subsequently, by employing a 3D analyst tool, a three-dimensional surface of the near shore bathymetry was generated and comparisons were made with the pre-tsunami bathymetry. Based on comparisons of selected profiles, conclusions were drawn as to changes that resulted from the tsunami’s impact. The analysis indicated that the tsunami deposited loose inner shelf sediments that altered significantly the near shore region bathymetry of the Kalpakkam coastal region. Sediment accretion changed the local bathymetry by 10 to 50 cm.