Assessing the shoreline trend changes in Southern tip of India.

Variations in shoreline trend was examined for 21 stations between Manuvai (in the west) and Vijayapathi (in the east), along the southern tip of India. Multispectral satellite data of Landsat MSS (9th Feb, 1973), Landsat TM 5 (4th Sep 2001) and Landsat ETM+ (21st Jan 2006) were used to assess the temporal dynamics of shoreline trend present in the region. The images were pretreated by radiometric calibration in order to avoid the temporal deviation of spatial and spectral information. The exact shorelines were estimated by two steps of image processing techniques: Normalized Difference Water Index (NDWI) is used to classify the land and sea water by and Sobal edge detection techniques are used to extract boundary line between land and water body. The rate of changes between the period 1973 and 2006 has shown that, the average shoreline rate is accelerated in the study area at 1.78 m/year. However, unusual shoreline changes ranging from 3.60 m/year to 15.60 m/year has been observed between the period 2001 and 2006 due to the impact of Tsunami. The station-wise shoreline data endorsed that Chinna muttom to Visvanarayanapuram and Lipuram are under continuous depositional process whereas other stations are under erosional process. This result shows that littoral sediment movement, with respect to the wave climate and anthropogenic activities are the predominant factors that affect the shoreline trend and sediment drift prevailing in the coast. [ABSTRACT FROM AUTHOR]