Coastal erosion hazard and vulnerability assessment for southern coastal Tamil Nadu of India by using remote sensing and GIS

摘要

Coastal hazards in many areas of the world are increasing as a result of rapid changes in various geological and physical variables driven by dynamic coastal processes. Development activities, global warming, climate change and sea-level rise not only introduce any new types of coastal hazards, but they also affect the existing hazards. The southern coastal Tamil Nadu of India faces severe threat due to rapid changes in geology and geomorphology, sea-level change, tropical cyclones and associated storm surges. In this present work, erosion hazard and vulnerability level along the southern coastal Tamil Nadu have been assessed using remote sensing and GIS. The erosion and accretion made in different parts of the study area have been measured and analysed. The coastal vulnerability index (CVI) has been used to map the relative vulnerability along the study area. The CVI ranks both geological and physical variables in terms of their physical contribution to sea-level rise and vulnerability. The data within the coastal vulnerability index show significant variability at different spatial scales. The vulnerability is caused by a complex interaction of various natural and human-induced coastal processes. The natural processes due to geology and geomorphology, the combined action of waves and currents, variations in sea level, tectonics and storms affect the vulnerability. The human activities include manipulation of hydrological cycles through construction of buildings along beaches, coastal structures such as harbours, beach protecting structures and jetties, mining of beach sand, destruction of protective dune systems. Thus, the present study clearly focuses on the vulnerability and risk parameters along the study area. It is also recommended that proper coastal management plans, beach filling and nourishment projects should be made to save the coastal area from severe erosion threat and hazards.