Modeling Coral Reef Susceptibility Using GIS Multi-Criteria Analysis

In this study a multi-criteria analysis model of GIS has been developed to map the susceptibility of coral reef based on various environmental indicators. For this there is a need to understand the pattern of coral susceptibility to environmental indicators including sea surface temperature (SST) which is continuously changing due to the global climate. The Northern Indian Ocean (NIO) has been selected as the study area which includes waters of Arabian Sea and Bay of Bengal. The purpose of this study is to highlight most vulnerable areas of coral bleaching in the NIO by using multicriteria analysis (MCA). Remotely sensed environmental indicators including SST, aragonite saturation state, bathymetry, photosynthetic active radiation (PAR), wind velocity, and reef slope were used to observe the susceptibility of coral reefs in NIO. Existing bleaching sites of corals were overlaid with susceptibility map obtained by MCA. The coast of Sri Lanka, South India, Maldives, Oman and British Indian ocean territory were found to be in the highly susceptible zone of coral bleaching. GIS-based MCA proved to be an efficient technique to analyze the suitable or unsuitable conditions for coral reef susceptibility.