Analysis of shoreline changes along the coast of Tiruvallur district, Tamil Nadu, India

Abstract

Shoreline change is considered as one of the most dynamic process, which was mapped along the coast of Tiruvallur district by using topographic maps of 1976 and multi-temporal satellite images. The satellite images were pertaining to 1988, 1991, 2006, 2010, 2013 and 2016 which were used to extract the shorelines. It is important to map and monitor the HTL (High Tide line) at frequent time interval as it considered as shoreline, which was demarcated by using visual interpretation technique from satellite images and topographic maps. Followed by this, an overlay analysis was performed to calculate areas of erosion and accretion in the study area. The results revealed that the coast of Tiruvallur district lost 603 ha and gained 630 ha due to erosion and accretion respectively. It was confirmed after the ground truth survey carried out in the study area. The high accretion of 178 ha was found nearby Pulicat Lake and low accretion of 19 ha seen between Pulicat lake to Kattupali port. The high erosion area was found along the Pulicat lake, Kattupali and Ennore ports, and Ennore creek mouth and south of Ennore such as Periya Kuppam, Chinna Kuppam, Kasi Koil Kuppam, and Thyagarajapuram. It may be concluded that the main causes of coastal erosion and accretion in the study area are anthropogenic and natural factors, which alter the coastal environment.