Shoreline management plan for a medium energy coast along west coast of India

Abstract

Studies on coastal hydrodynamics and sediment transport help to unravel the coastal processes and facilitate formulation of shoreline management plans. An integrated approach which includes, extensive field data collection and numerical modelling is lacking along most of the coasts around the world, particularly along Indian coasts. The coastal stretch from Beypore to Puthiyappa, southwest coast of India has been selected for this present investigation. Harbour breakwaters in the northern and southern boundary of the study region have major impacts on shoreline modifications along this sector. In addition, a small harbour and associated breakwaters are located in the middle of the study region. Seawalls, and combination of seawall and smaller groins are constructed at many places as part of coastal protection. Sediment transport along the coast was computed with LITDRIFT model and the results show net northerly drift of 1.5 * 105 m3/year. The model results are comparable with the quantity of beach sediment mined from Puthiyappa beach (approximately of 0.8 * 105 m3/year). In addition, illegal mining is carried out in the region. Further, the model computed the shoreline evolution along the sector and major accumulation occurs south of Puthiyappa breakwater. Sand deposition close to groins and breakwaters along the study region support the model results. No further intervention along this sector is required for shore protection except, the maintenance of the existing protective measures such as seawalls and groins.