Shoreline Response Evaluation System (ShoRES) – Case studies

A large number of coastal structures have been constructed along the Indian coast for ports, harbors, shore protection, houses, industries etc for various human requirements, which are often found to result in major erosion/accretion issues along the coast making them counter-productive to the objective of coastal protection. Erosion results in loss of valuable land and property while accretion results in closure of river mouths resulting in floods in the upstream locations due to negligible exchange with the seawater. This is largely due to inadequate understanding of the morphological changes along the coast and shoreline response to introduction of structures and / or natural changes. More often coastal protection structures are built as an emergency response to shoreline changes from human and / or natural impacts which result in aggravating the situation. Detailed analysis of shoreline response several times indicate that a ‘Non-interference’ might have been a better solution.It is therefore essential to design and develop, site specific coastal and estuarine infrastructure using the state-of-the-art analysis tools available for sustainable and effective performance. This study proposes to include the impact of coastal structures on the shoreline morphology through proven scientific techniques and identification of environmentally sustainable mitigation measures / resilient solutions. For meeting this objective, it is essential to create a database of morphological changes along the coastline of India based on NIOT’s long term experience in coastal engineering. This data base shall enable the planning and design of sustainable infrastructure and shore protection schemes based on secondary and field data.In this paper two case studies along the Indian coast are discussed. From the analysis of historical data on the behavior of shorelines, it has been possible to evaluate the root cause of erosion/accretion. This is followed by use of numerical models for prediction of response considering site specific issues. The development of database of shoreline changes and the response of shoreline to various manmade / natural changes (ShoRES) enables incorporation of resilience in the mitigation measures thereby enabling creation of solutions that are sustainable.