THEENADHAYALAN, G.; KANMANI, T., and BASKARAN, R., 2012. Geomorphology of the Tamil Nadu coastal zone in India: applications of geospatial technology.The world's coastal environment is made up of a wide variety of landforms manifested by a spectrum of sizes and shapes, ranging from gently sloping beaches to high cliffs. Despite the diversity, coastal landforms are best considered in two broad categories: erosional and depositional. In reality, the overall nature of any coast may be described in terms of one or the other of these categories. An attempt is made in this paper to describe the areal extent of coastal morphology along the entire Tamil Nadu coast, within a 3 km buffer zone. In fact, the Tamil Nadu coast has now become a topic of considerable interest due to the threat of tsunamis and other devastating processes prevailing in this area. Thirty-three geomorphologic features covering an area of 2765 km2 and spread over the length of 1117 km were identified and studied spatially and temporally to assess their past and present status. Moreover, the effect of tsunamis on these features was investigated and is discussed in detail. Analysis of the results shows that any one of the relief features present along a given coast is the result of a combination of processes, sediments, and the geology of the coast itself. Beaches, for example, were located only in the central-northern and southern parts of the study area, while the central part is devoid of beaches. Before the last tsunami in 2004, the measurable extent of beaches throughout the study area was increasing due to continuous sedimentation process occurring during 1992–2003. However, the tsunami of 2004 had a major impact on the Tamil Nadu beaches, resulting in their modification. Similarly, other features are treated in this paper.