Applications of the multi-spectral satellite data from IRS-P6 LISS-III and IRS-P4 OCM to decipher submerged coral beds around Andaman Islands

Abstract

The coral reef of Andaman Sea is one of the least explored regions of the Indian Ocean. The coral reefs are the tropical fauna forming the important eco-system in the tropical ocean. The coral reefs grow in the suitable climatic conditions. The coral reef systems of Andaman region are unique from ecological perspective. The reefs found around Andaman region are fringing type of reef. Most of this reef is found in the shallow depths especially in the photic zone along the coast. There are even reef banks exist along some ridges in the offshore region away from the coast. Some areas are remaining unmapped due to isolated from the coast. The satellite data can able to detect the signatures of the submerged reef banks. Multi-spectral bands of IRS series P6 LISS-III and P4 OCM satellite data deciphering the information about submerged reef bank in Andaman Sea. The shorter wavelength from OCM spectral band3 (480-500 nm) and LISS III band1 (520-590 nm) were found useful in mapping submerged reef bank. The spectral signatures of these areas are similar to the mapped/observed submerged reef banks. The depths of these areas are from 25-70 meters observed based on the NHO charts and GEBCO bathymetric data. The current study brought out the possible areas of the submerged reef banks in the environs of the Andaman Island.