Impacts of coastal protection measures along the coast of Kerala, India (through remote sensing techniques)

The maritime state, Kerala, is located along the southwest coast of the Indian peninsula, which extends from Trivandrum district (8° 17´ 41.03´´ N, 77° 5´ 37.29´´ E) in the South to Kasaragod district (12° 45´ 20.76´´ N, 74° 51´ 58.92´´ E) in the North, exposed to the waves from the Arabian Sea. The shoreline is extremely dynamic due to the impact of waves, tides, currents, coastal orientation and other associated occasional coastal hazards. The annual climatic calendar for the Kerala coast can be broadly classified as South-West monsoon (June to September), North-East Monsoon (October to December), and Pre-monsoon or Non-Monsoon (January to May). Prior to the 2004 Indian Ocean tsunami, a standardised seawall section had been preferred for highly eroding coastal stretches. The coastal hazards in addition to the tsunami impact paved the way for considering several other structures for coastal protection, of which groyne fields have been predominantly implemented. As it is essential to quantify the performance assessment of these protection measures, an exercise using the DSAS (Digital Shoreline Analysis System) tool was carried out, the results of which are presented and discussed in this paper. © 2024 Indian Society for Hydraulics.