Potential Of Coral Reef Resources Based On Alos Image In The Pagai Island Region, West Sumatra

Abstract

Analyse of Alos satellite data recorded on the 11 Januari 2007 using depth invariant index algorithm and integrated of 33 field data has produced the classification of 166 hectares of coral reef ecosys- tem in the waters of Pagai Island into five classes of: live corals (5.5 %), dead corals (16.6 %), rubbles (15.8 %), mix substrates (13.9 %) and sand (38.3 %). Aggregation of corals in the east of island are grown and spread out at the reef slopes environment while almost of reef flat areas were covered by sand substrates. In the west ar- eas, aggregation of corals is observed in deep water up to reef slope areas while the reef flat areas are occupied by rampart materials. The algorithm that composed of three visible bands is applicable in clear water rather than in turbid water environment. Vegetation cov- ers such as seagrass, seaweed and macro algae are not identifiable due to its narrow extent, and usually are associated with turbid wa- ters. The research activity which is funded by Critic Coremap - LIPI is aimed in producing Pagai Island map of coral reef ecosystem.