Shoreline changes and reef strengthening at Kavaratti island in Lakshadweep Archipelago - A case study

摘要

The Lakshadweep islands experience severe coastal erosion problem every year due to high monsoonal wave activity. Majority of the islands in the group are surrounded by a reef on the western part which acts as a first line defence for the incoming waves. It was documented from many earlier studies that the reef height in many of these islands has decreased due to both natural and human activities. In many of the islands in the group the widening of entrance channel has been carried out by cutting reef edge as early as in 1971 resulting in high waves entering the lagoonal coast causing high erosion at certain stretches of the island coast. In this paper we are presenting the Kavaratti Island as a case study through systematic collection of beach profiles and monitoring of littoral environment observations for waves and currents. Further, an attempt has also been made for a feasibility study of reconstruction of part of the reef (similar to 400 m length) on the northern part of the island through numerical modelling studies which indicates that the reef strengthening would stabilize the beach. Adopting suitable remedial measures to allow free movement of trapped sediments could be an environment friendly soft measure that would further improve the condition of the island coastline.