Spectral Discrimination of Coral Reef Benthic Substance and Implications for Environmental Protection

Abstract

Spectral reflectance of benthic substance is a fundamental parameter to coral reef environmental protection by remote sensing technology. It collected in situ a total of 44 spectral reflectance of healthy coral, fine sand, dead coral, sand mixed with coral rubble, and sea grass in Leizhou peninsula, China. Analyses of spectral reflectance revealed that there exist three distinct spectral zones, the high reflectance zone (400-580nm), the attenuation zone (580-720nm) and low reflectance zone (720-850nm). The reflectance between 400 to 580nm band range can be used to discriminate coral reefs and other substances efficiently. Meanwhile, water depth and quality has great influence on coral reef spectrum. By using spectral response function, analyses of simulated reflectance spectra for several remote sensors (ETM+, SPOT5, IKONOS, Quick bird) indicate that narrowband multispectral sensors have the ability to discriminate different benthic substances. The research demonstrates that basic reef benthic classes are spectrally identifiable and differentiable; it establishes the basis of utilizing remote sensing technology for environmental protection of coral reef ecosystem.