Coral reef applications of Landsat-8: geomorphic zonation and benthic habitat mapping of Xisha Islands, China

Being one of the most significant and valuable coral reef systems in South China Sea, Xisha Islands has undergone rapid transformation due to increasing stressors from human impacts climate change recent years. However, as indispensable information for monitoring management, detailed extent, geomorphic zonation, or benthic composition is not well documented. Considering limited access Islands, development optical remote sensing technology provides us with a feasible mean observation. This study adopted water depth substitution index – probabilistic inundation (PI) combined depth-invariant (DII) achieve extent exploration, geomorphologic habitat types classification unsupervised algorithms based on Landsat-8 time-series satellite data. Compared two open-access datasets, each independent extracted PI exhibited higher similarity actual boundary conditions displayed RGB (Red-Green-Blue) composite images Landsat-8. Based derived slope, we obtained zonation results, similarly compositions were retrieved PI, DII, reflectance. The overall accuracy results 72% 86%, respectively. We also interestingly discovered that corals may be capable an ability resist chronic heat stress growth trend area after successive events 2014–2015 observed at reefs. proposed mapping framework this repeatable flexible scheme depicting comprehensive situation reefs only publicly available data without complicated pre-set parameters, which could easily extended research around world. Simultaneously, findings provide requisite supporting sustainable management conservation ecosystems Islands.