Impacts of coastal in stability (erosion) on sea side communities: southern tip of India, Kanyakumari
Résumé
The coastal area is a dynamic and fragile environment which is very essential for many purposes such as resident, recreation, tourism, fisheries, agriculture, etc. Agriculture and fishing are the major source of developmental activities done by the local community in the coastal region. Therefore, coastal instability will directly affect the socio-economic conditions of the people residing nearby the coastline. This coastal instability will occur by both natural (Sea level rise, erosion and accretion) as well as anthropogenic factors (recreational activities, developmental activities and the construction of protection structures). This change in coastline will create a socio-economic impact to the local community. This study examines the changes in shoreline that occurred during the past two decades (2000 to 2020) along the Kanyakumari region in the southern tip of India. The results indicate a major retreat with some sea-ward movement due to sediment accumulation. Even though, the shoreline appears to be naturally dynamic due to long shore currents and beach morphology, the sediment movement due to external anthropogenic pressure exhibited a direct impact over the shoreline. A large part of the shoreline experienced erosion during the study period mostly due to construction of protective structures such as groins, jetties and sea walls.
Major erosions were observed over the regions nearby harbors. Compared with the east coast region, the western part experiences more erosion which may be due to high energy waves. Coastal dunes in the Rajakkamangalam sector especially in locations Chothavilai, Sanguthurai, Periyakadu and Rajakkamangalam acts as a barrier against wind and waves keeping the inland areas safe from coastal hazards. More number of jetties and breakwaters were constructed during the past decade which eventually induces erosion in the one side and deposition on the other. Coastal villages such as Poothurai, Thengapattinam, Melmidalam, Colachel, Manavalakurichi and Kovalam experiences higher rate of erosion. This increased erosion will leads to the destruction of coastal properties and reduced fish catches which will deploy the economic growth of the region. It is also noted that, the coastal stretches should have been planned and monitored better through continuous observation of sea level rises and other potential environmental hazards. Hence, there is a need to develop proper interventions for sustainable coastal resource utilization.