Comparison between measured and simulated shoreline changes near the tip of Indian peninsula

The coastline of Kannyakumari (8°4′N 77°33′E to 8°13′N 77°14′E), along the Arabian Sea is located near the southern tip of the Indian peninsula. This coast experiences heavy erosion particularly during the seasonal monsoons. This in turn results in considerable damage to properties, economic loss and leads to a number of socio economic problems. Protection measures in the form of groins have been implemented at selected locations along the coast. Prediction of shoreline oscillation due to the presence of such structures is extremely important prior to their construction. Although several formulae are available in the literature for the prediction of long shore sediment transport, studies regarding their application and validation with field problems along this coast are scanty. In the present work, seasonal measurements of shoreline oscillation adjacent to the shore connected structures were carried out during the year 2007 for which satellite data have also been adopted. These measurements are adopted to validate a finite difference based numerical model based on the formulation of Janardanan and Sundar (1994) for the prediction of shoreline evolution in the presence of shore connected structures. The offshore wave climate for the year 2007 is simulated from National Centre for Environmental Prediction (NCEP) wind data using Wave Analysis Model (WAM) model, whereas, the near shore wave climate was derived by adopting MIKE21 Parabolic Mild Slope (PMS) module The alongshore sediment transport is calculated using the approach of Van Rijn (2001). The prediction revealed that the net average annual alongshore transport varies from about 0.008 to 0.040 million m3 and is towards the west.

► Application of satellite images, field measurements and numerical modeling have been combined for the prediction of the shoreline changes due to shore connected structures.
► Among the Formulas of CERC (1984), Kamphuis (1986) and Van Rijn (2001) the prediction of alongshore sediment transport near the tip of Indian peninsula formula of Van Rijn (2001) was found to be good.
► A continuous monitoring of the shoreline changes has helped in understanding the behavious of shoreline dynamics.