Delineation of sensitive coastal zone of northern Ramanathapuram coast, Tamilnadu, India, using a GIS approach

Abstract

This research aims to assess the sensitive coastal zones by analyzing the shoreline changes such as accretion and erosion in the eastern coastal part of Ramanathapuram District, Tamil Nadu, India. The study focused on Mandapam, Pirappanvalsai, Enmanamcondam, Nagachi, Terbogi, Athyuthu, Chitrakkottai, Pathengal, Attangarai, Alagankulam, and Devipattinam villages. Some of these areas are distinguished as highly sensitive ecological zone. The erosion of an area leads to irreplaceable disturbances to nature. Hence, erosion and accretion studies are top priorities when studying the coastal area. In addition to GIS technology, which has been widely used in the past 20 years, the End Point Rate (EPR) and Linear Regression Rate (LRR) analyses were conducted to better understand the shoreline changes. The stability of the coastal region was analyzed by observing the slope variations of the beach during the profile survey. In the study, we analyzed that the Quaternary deposits of sand are the dominant geological feature of the study area. Coral reefs and salt pans are highly distributed along the coastal stretch. The coast of Mandapam village has been detected as a highly sensitive region, with an average erosion rate of −3.1 m/yr and an average accretion rate of 1.22 m/yr, resulting in high erosion and low accretion. The coast is a steep coast with an average slope angle of 0.24°. This study provides insight into sustainable coastal zone management.

Keywords

• End point rate
• Linear regression rate
• Geographic information system
• Beach profile
• Ramanathapuram