Geomorphological Analysis of the Coral Fringed Coasts of Andaman and Nicobar Islands Using Geospatial Techniques

Abstract

The island groups of Andaman and Nicobar are fringed with coral reefs on the seaward sides of the Andaman Sea and the Bay of Bengal. Favourable conditions, such as sea water temperatures, sediment-free water, west coast swell waves, attachment banks, sunlight penetration up to the upper 30 m depth, salinity, and nutrient levels in the sea water, aided better coral growth on the western shores of tropical oceanic islands. Hermatypic corals with zooxanthellae flourished along the island fringes of the various types of shoreline characters in the tropical warm waters of the Andaman Sea. The general topographic characteristics of the coral reefs are represented on the sea face by algal ridges, sloping buttress zones, and reef faces that extend downward and island fringe shore platforms with inter tidal patch reefs and reef terraces that extend landward of the algal ridge in the region. They are also diverse in their growth characters on the basis of the shoreline configuration types and shallow water conditions. Massive corals, branching corals, table corals, fern corals, and brain corals are commonly found on the steeper banks of the seaward sides of these groups of islands. Adverse impacts are produced on the coral reef habitat by seismo-tectonic events, tsunami events, bleaching events, coastal development and tourism pressures, and the frequent events of cyclones in the region. The paper aims to identify the geomorphological diversity of the coral fringed coasts of the Andaman Sea and Bay of Bengal, as well as the environmental effects caused by the events of hazards along the Andaman and Nicobar group of islands using geospatial techniques.