Classification of Coastal Belts on the Coral Coast of Viti Levu, Republic of Fiji, South Pacific, using the BCCS (Biophysical Cross-shore Classification System)

Abstract

Finkl, C.W. and Makowski, C., 2022. Detailed interpretation of satellite images of coastal belts on the Coral Coast of Viti Levu, Republic of Fiji, South Pacific, using the BCCS (Biophysical Cross-shore Classification System). Journal of Coastal Research, 38(3), 491–511. Coconut Creek (Florida), ISSN 0749-0208. Lying on the southwest Fijian coast of Viti Levu, the Coral Coast is noted for its fringing coral reefs that extend for an overall alongshore length of about 80 km (from Momi to Suva), with the study area being a 32-km-long subset in the Sigatoka region. The fringing reefs, extending offshore for an average maximum distance of about 650 m, are broken into contiguous segments by deep-water cross-shore channels composing discrete coastal belts. When the fringing reef segments are combined with other onshore (terrestrial) eco-geomorphological units, they make up nine distinct coastal belts in the study area comprised by 35 domains. The cross-shore classification of the Coral Coast examples was based on application of the BCCS (Biophysical Cross-shore Classification System), which required interpretation of satellite images to comprehend cross-shore catenary (linked) sequences that had alongshore extent. Imagery from 2010 to 2017 was accessed to obtain the best possible views of each reef segment and adjacent mountain hinterland. Due to spatial limitations, capabilities of the Google Earth Pro platform were accessed to acquire sufficient interpretive details for compilation of cross-shore transectal archetypes and subarchetypes from the reef front to coastal mountain slopes. Typical cross-shore classificatory sequences consisted of Coral Reef (Cr), Flat (F), Beach (Be), and Mountain (M) archetypes that formed tetrasequent Cr-F-Be-M catenas. Although a limited number of small Delta (De) archetypes overrode back-reef flat margins, their frequency of occurrence was not a domainal characteristic. The occurrence of Developed (Dv) archetypes were more or less ubiquitous onshore, whereas alongshore bedrock outcrops of the Rock (R) archetype were rare. Because the scale of natural and anthropogenic features along the coast demanded a detailed (hectometric) coastal classification, the BCCS was applied on an experimental basis to ascertain its applicability as an exemplar for similar studies in insular settings elsewhere.