Development of Shoreline Response Assessment System for Planning Sustainable Shore Protection Measures

The response of the shoreline to natural interfaces like creeks, estuaries, bays and engineering installations such as ports, harbours, groins, breakwaters etc., is of great significance to sustainable shoreline management as it is often observed that these interfaces / structures play a major role in altering the shoreline causing erosion and accretion largely due to their intervention with movement of alongshore sediments. Long term evaluation of the performance of these structures and the corresponding shoreline response is essential to understand the effects on the shoreline and for planning mitigation measures for management of adverse impacts. National Institute of Ocean Technology (NIOT) a Research and Development organization under the Ministry of Earth Sciences (Government of India) had taken an initiative of assessing the effects of various coastal structures on the shoreline along the coast of India. The aim of this study was to assess the impacts of coastal structures on the shoreline behaviour and thereby enable designing and implementation of environmentally friendly coastal infrastructure. This paper discusses the various phases of the study carried out along the coast of Tamilnadu state of India for evaluating the effects of various engineering structures. The coastline from Pulicat in the North to Neerody in the South, stretching across 1076km was covered as part of the study and 260 manmade structures were mapped. Potential sites were identified and behaviour of shoreline was simulated using numerical models which were calibrated using long term field data. The calibrated model was used for evaluating alternative options for shoreline management at select sites for mitigating the impacts of erosion / accretion caused by the structures. The entire work carried out was compiled and published as part of an atlas titled, Digital Information on Shore System Effects due to Manmade Interventions and Natural Alterations by Technological Evaluation (DISSEMINATE).