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

The Biophysical Cross-shore Classification System (BCCS) was designed as a shorthand notation for cross-shore classification (Finkl and Makowski, 2020a,b,c,d, 2021a,b,c,d, 2022a,b). The system incorporates marine, coastal, and terrestrial eco-geomorphological units from indefinite distances offshore to onshore and thus encompasses marine and terrestrial coastal environments. Because cross-shore transects have alongshore spread (width), the resulting shore-normal catenas can be used as descriptors for a coastal classification that incorporates inland extent with marine conditions. The universal applicability and flexibility of the BCCS enable characterization of natural and anthropogenically developed coastal belts under a wide range of environmental conditions that can be interpreted from satellite images. While nominal scales of observation follow kilometric spatial distribution patterns, some coasts demand closer inspection at hectometric scales due to the intricacies of biophysical environments, such as those along many coasts with coral reefs. For example, the fringing coral reefs that occur in the Fijian Archipelago require detailed surveys to comprehend the morphological intricacies of the reef environments. The Coral Coast on the southwestern flanks of Viti Levu, which supports some dramatic examples of fringing reef coastal belts that are backed by developed tropical mountain slopes, provides an opportunity to test the flexibility of the BCCS.

The aim of this research was to test the hypothesis that fringing reef coastal belts can be subdivided into eco-geomorphological units based on cross-shore archetypical concatenations that have alongshore spread. This experiment was regarded as a test because of the extreme similitude and continuity of fringing reef segments that front natural terrestrial landscapes and developed zones. The goal of this examination along the Coral Coast on Viti Levu was to ascertain the applicability of the BCCS to tropical coasts with long stretches of fringing reef environments. Based on interpretation of extant and historical Google Earth Pro satellite imagery, a classification of the fringing reef coastal belts is presented at decametric to hectometric scales for subregional to local coverage of the study area that encompasses about 64 km² (6400 ha) from the reef front to a maximum distance of 2 km inland, but access to zoom capabilities was required to ascertain certain microscale details of the reefs, such as the occurrence of patch reefs (Figure 1). With these scalar restrictions in mind, the purpose of this test was also to ascertain the practicality of determining cross-shore catenary associations of coastal archetypes that include fringing reefs along 32 km of tropical mountain coasts.

The Fijian Archipelago, which comprises the Republic of Fiji, lies in the middle of the South Pacific Melanesian region about 3150 km from Sydney, New South Wales, Australia, and 2100 km northeast of New Zealand. Representing the hub of the Southwest Pacific, Fiji lies midway between Vanuatu and Tonga (e.g., Stokes, 1971). The archipelago, located between 176°53′ and 178°12′ E longitude, is roughly 194,000 km² (of which around 10% is land) and retains an oceanic exclusive economic zone (EEZ) of 1.3 × 10⁶ km² (e.g., Mangubhai et al., 2019). The island of Viti Levu lies north (equatorward) of the Tropic of Capricorn between 18°15′ and 17°15′ S latitude. Consisting of 332 islands (of which 106 are inhabited) and 522 smaller islets, the two most important islands are Viti Levu and Vanua Levu, which together account for about three-quarters of the total land area of the country (NgCheong-Lum, 2005). The capital city of Suva, which is home to nearly three-quarters of the population of the republic, lies on the southeast coast of Viti Levu and about 80 km east of the study area. For a quick overview, the essential characteristics of the coastal and marine ecosystems of Fiji have been summarized by Mangubhai et al. (2019), while particulars of the study area are briefly indicated in the paragraphs below with regard to summary geology, climate, ecoregions, and large marine ecosystems.

The oldest rocks in most of the mountain islands in the archipelago were formed by island-arc volcanic rocks of Late Eocene age (e.g., Kumar, 2005; Terry, Ollier, and Pain, 2002). Their subsequent uplift allowed deposition of shallow-water limestones around them, but after 28 Ma, another major suite of volcanic rocks in the form of plutonic intrusions was emplaced to produce the first significant landmass of Viti Levu (Neall and Trewick, 2008). These strata are now exposed on the southern flanks of the island. At 1324 m elevation, Mount Tomanivi (previously named Mount Victoria and also known as Tomaniivi) constitutes the highest mountain in Fiji and is an extinct volcano located in the northern highlands of Viti Levu (Derrick, 1951). Developed volcanic slopes that reach down to the coast in the study area contain small villages, tourism accommodations, and small agricultural enterprises. The interior of the island is characterized by maturely dissected, insequent hills (Foye, 1917) that are underlain by sandstones and marls that stand in contrast to the volcanic rocks of the coast.

Due to the presence of mountainous terrain, orographic precipitation on Viti Levu is characterized by windward (eastern) parts of the island receiving more rainfall than leeward (western) zones, which are consequently drier. Strong climatic contrasts thus occur between the wet and dry sides of the large island, producing diverse soil-topographic landscapes (e.g., Kumar, 2005; Leslie, 1997). Thus, based on the Köppen-Geiger climate classification system (e.g., Kottek et al., 2006; Peel, Finlayson, and McMahon, 2007), eastern parts of the island in the region of Suva are classified as having a tropical rain-forest climate (Af), where annual rainfall averages about 1900 mm, and temperatures hover around 24°C, moderated by southeast trade winds. The western rain-shadow parts of the island have a tropical savanna climate (Aw). The bifurcated wet and dry climatic regimes are reflected in different types of ecoregions, whereas air temperatures are modulated by the surrounding ocean waters. Typical of tropical insular climates, surrounding ocean surface water temperatures around the island of Viti Levu average about 27°C (Climate-Data.org, 2021).

Two distinct ecoregions (ER) exist within the coastal belt study area (Figure 1). The Fiji Tropical Moist Forests Ecoregion (ER622) characterizes eastern parts of the island, where moist tropical forests occur as lowland and montane rain forest, with cloud forest at higher elevations (Olson, 2021). Cloud forests, scattered above 600–900 m on the ridges and peaks of the largest islands, are dominated by tree ferns. About 40% (7570 km²) of the original moist forest remains in rugged mountains, but most lowland habitats have been cleared for settlement, agriculture, and mahogany plantations. The Fiji Tropical Dry Forests Ecoregion (ER635) occurs in the western rain shadow of Viti Levu, where dry forests have a lower canopy height than the adjacent moist forests, which include trees that are more gnarled and thicker with vines. Fiji's ancient palm-like cycads are largely restricted to these dry forests (Olson, 2021).

Considered as a whole, the Fijian Archipelago supports a wide range of reef types, including fringing, platform, pinnacles, submerged, barrier, oceanic ribbon, atolls, near-atoll, and drowned reefs covering 4550 km² (Mangubhai et al., 2019). Fiji is surrounded by one of the largest coral reef systems in the Southwest Pacific. The Coral Coast of Viti Levu, however, is so named in reference to the nearly continuous string of fringing and patch coral reefs that occur alongshore for some 80 km, constituting the country's longest continuous fringing reef system that centers on the Korolevu-i-wai District. The fringing reefs along the southern shore of Viti Levu are characteristic of the types elucidated by Smithers (2011), where the reefs are shore-attached with shallowly submerged back-reef areas. These kinds of reefs typically contain three main zones that are identified as fore reef, reef crest, and back reef (Guilcher, 1988; Kennedy and Woodroffe, 2002; Nunn, 1994; Sheppard, 2005). More specifically, the fringing reefs of the Coral Coast occur as distinct aprons that are broken alongshore by cross-shore channels that are fed by freshwater from mountain streams debouching into the ocean. The study area contains 10 distinct sets of fringing reefs divided into cohesive segments by shore-normal, deep-water channels, some of which form embayments, such as Sovi Bay, resulting from the Sovi River outlet about 1 km west of the Korotogo village, as shown in coastal belt CB5 (Figure 1). Beaches along the Coral Coast tend to be very narrow, averaging less than 10 m width and exceptionally ranging up to 20 m in dry beach width. These Coral Coast beaches are mostly rocky and strewn with dead coral, which at low tide makes them difficult to use and not aesthetically pleasing. The beaches, which are perched on the landward margins of reef flats, immediately transition seaward to calcareous sand, coral detritus and debris, dead remains of reefs, or living patch reefs. Most beaches lack dune systems, and in undeveloped areas, they grade sharply into mangroves or rain forest.

Occurring 4800 km south of the Hawaiian Islands, a new Large Marine Ecosystem (LME) is extrapolated from the tropical Northern Pacific Ocean to the Fijian Archipelago in the Southern Pacific Ocean to create the Insular Pacific–Oceania Large Marine Ecosystem (LME67) (Figure 1). The Insular Pacific–Oceania LME (LME67) includes a range of islands, atolls, islets, reefs, and banks extending outward into the Pacific Ocean northeast of the North Australian Shelf LME (LME39), the Northeast Australian Shelf LME (LME40), and the East Central Australian Shelf LME (LME41) (Imehub, 2021). Equatorial currents and predominant northeasterly trade winds influence this marine ecosystem, which includes more than 10,000 islands, has approximately 822,000 km² of total land area, and exhibits a tropical climate. Areas included in this LME67 are the collective areas of Melanesia, Micronesia, and Polynesia. Fiji itself has an extensive and high diversity of marine habitats, including estuaries, seagrass, macroalgal assemblages, protected and exposed soft shores, lagoons, coral reefs, and slopes. Even though LME67 encompasses a large island chain, the oceanic environment is typical of the deep open ocean.

Procedures adopted in the BCCS (Biophysical Cross-shore Classification System) follow those originally outlined by Finkl and Makowski (2020a) and updated for inclusion of the developed archetype (Finkl and Makowski, 2021c, 2022a). By incorporating a range of subarchetypes, the system is applicable to all coastal belts that are in natural environmental states or anthropogenically modified, as occurs along the tropical Coral Coast of Viti Levu, where many villages and recreational facilities line the coast.

The basic methodology for applying the BCCS entails interpretation of satellite images at myriametric scales, which involve a presentation scale for publication and operational zooming scales that are required for identification and close (detailed) inspection of spatial relationships between eco-geomorphological units. This geographic perspective is oriented to interpretation of cross-shore transects that traverse a coastal belt from offshore to variable distances inland. Eco-geomorphological units occurring in the cross-shore transects are alphanumerically coded according to the terminology in Table 1. The classification was applied as an open-ended system to accommodate the diversity of features associated with a coral coast.

Google Earth Pro was used as an interactive platform to acquire and inspect satellite images. Due to the variable range of image quality along the Coral Coast, historical image sets were accessed using the Historical Imagery Tool in addition to the most recent postings. By so doing, the best quality imagery was accessed for application of the BCCS, resulting in the following image acquisition dates for coastal belts (CB) as shown in Figure 1: CB2 (2010), CB3 (2014), CB4 (2016), and CB5 through CB10 (2017). In this way, issues related to water clarity, partial cloud cover, sea surface glint, wave diffraction patterns, and tonal variations between scenes could be accommodated by selection of the most visually pleasing images.

Application image analysis and qualitative tools were accessed to acquire elevation and distance measurements at various scales using zoom capabilities. Google Maps and Google Earth on Web were interactively accessed to acquire place names. The variably dated satellite images incorporating fringing reefs and terrestrial mountain slopes were saved at 4800 × 4800 pixels in Google Earth Pro and then imported to GNU Image Manipulation Program (GIMP) for qualitative image analysis, scaling (to 600 pixels/mm), and image enhancement, if required. The images were then annotated in Microsoft PowerPoint by working back and forth with the imagery in Google Earth Pro using the zoom tool to interpret the detailed coastalscapes. The large-scale nature of the coastal belts required detailed investigations of the reef systems at hectometric scales in order for features of the fringing reefs to be comprehended as well as the determination of patch reef occurrence on the back-reef flats. Selection of a nominal image scale of about 500 m was thus needed to accommodate the details of the fringing reef environments. Bar scales showing 500 m length are provided for all figures except Figures 5, 6, and 8, where a 1 km bar scale is used for somewhat longer coastal stretches that are respectively 4.65 km, 5.7 km, and 4.1 km. The alongshore lengths of the remaining image scenes ranged from 1892 m (Figure 2) to 3975 m (Figure 10). The selection of a meter or kilometer bar scale depended on convenient proportional image viewing widths for presentation.

Straight line segments were used to estimate alongshore distances of the domains included in Tables 2 through 10. Measurements were made from consecutive fringing reefs that were easily identifiable along the shore and separated from one another by shore-perpendicular deep-water channels. For the study area, a total alongshore distance of 32 km was used as a basis for calculating percentages of the total selected Coral Coast domains. Fringing reefs in the study area accounted for roughly half of the alongshore spread of the shore commonly identified as the Coral Coast, the length of which is estimated to be about 80 km (as measured between Waidroka Bay in the east and Natadola Beach in the west).

The results of this experimental classification of fringing reef coastal belts on the south coast of Viti Levu are summarized in Tables 2 through 10 and include domain archetype designations, alongshore lengths, the BCCS code sequence, and domain percentages of coastal belts and the overall study area. Figure 1 is provided as a location diagram that shows the locations of coastal belts 2 through 10 (see Figures 2 through 10, with coastal belts numbered from east to west as CB2, CB3, CB4, etc.), as well as terrestrial (tropical mountain) ecoregions (ER635 and ER622) and the Insular Pacific–Oceania Large Marine Ecosystem (LME67). A regional 10 km bar scale is provided for contextual orientation of the complete study area. Some towns and settlements are included to assist with geographical situational awareness along this 32-km-long stretch of the Coral Coast. The results of codifications for the various coastal belts (CB) are summarized in numerical order (CB2 through CB10) in the following paragraphs. Each coastal belt is discussed as a discrete eco-geomorphological unit, where fringing reef complexes are separated by shore-perpendicular channels that provide natural separation of reefs. All other subdivisions are subsidiary to this primary breakdown using deep-water channels as boundaries. Tertiary onshore variations in the codification sequences are related to types of anthropogenic development and vegetative cover archetypes.

This 1892-m-long coastal belt (Table 2), which lies immediately west of Maui Bay (Figure 2), is comprised by four fringing reef domains (Lomani Wai, Shambala, Namolevu, He-ni Uwa) that are respectively 497, 700, 350, and 345 m long. The Shambala domain occupies 37% of CB2, followed by the Lomani Wai Domain, which comprises 26.3% of CB2. These domains retain similar cross-shore catenary sequences that are based on archimorphic Coral Reef–Flat–Beach–Mountain (Cr-F-Be-M) tetrasequent catenas. This basic or foundational codification characterizes this coastal belt with domains differentiated on the basis of alongshore coastal belt configurations that were identified as broadly scoliomorphic (curved) or leiomorphic (straight) in plan view (cf. Finkl, 2004) (Table 1). Further differentiation of cross-shore sequences was related to the presence of natural features such as deltas or anthropogenic development, as in the case of the Lomani Wai Domain, where the codification breaks down to 7Cr_fr,paF_saDeBe_caM_fo,sr for a straight shore where a delta (De) is included in the catenary sequence, and the Shambala Domain 2Cr_fr,paF_saBe_caDv_reM_fo,sr, which includes a recreationally developed (Dv_re) curved shore. Codifications for fringing and patch coral reefs (Cr_fr,pa), sandy flats (F_sa), and mountains with forest and scrub vegetation (M_fo,sr) are featured in the Lomani Wai, Shambala, and Namolevu Domains, with the exception being the He-ni Uwa Domain, which retains a tidal channel in association with the sandy flats (F_sa,tc).

This 2880-m-long coastal belt (Table 3), which lies in the vicinity of Tagaqa village (Figure 3, Natavora Domain), is comprised by five fringing reef domains (Tagaqa, Hideway, Natavora, Black Rock, and Undu Creek) that are respectively 715, 415, 470, 730, and 520 m long. The Tagaqa and Black Rock Domains respectively occupy 25% and 26% of CB3. This stretch of fringing reef is weakly bifurcated by a shallow narrow shore-perpendicular channel that is about 10 m wide at its mouth (in line with the surf break). This small channel stands in contrast to the larger and deeper channels that demarcate this fringing reef, with a 200-m-wide channel to the east and a 125-m-wide channel to the west noted in Figure 3 by heavy shore-perpendicular red lines. The five domains in CB3 are distinct in that each retains eco-geomorphological features and developed facets that contribute to variable cross-shore catenary sequences. Perhaps noteworthy is the outcropping of igneous rock on the shore of the Black Rock Domain where the cross-shore Cr-F-R-M (Coral Reef–Flat–Rock–Mountain) tetrasequent codification expands to the full curved coast catenary association 2Cr_fr,paF_saR_igM_fo,sr. Other interesting features include small deltas that have formed where mountain streams enter the ocean, for example, as noted in the Tagaqa (4,7Cr_fr,paF_sa,tcDeBe_caDv_reM_fo,sr), Natavora (2Cr_fr,paF_sa,tcDeBe_caDv_coM_fo,sr), and Undu Creek (2Cr_fr,paF_sa,tcDeBe_caM_fo,sr) Domains. Most of the reef front is broadly curvilinear except in the vicinity of the large channels, where leiomorphic channel walls leading shoreward end up forming a U-shaped embayment, as noted for the Tagaqa Domain by the 4 and 7 numerical identifiers for shoreline configuration (see Table 1). Commercial and recreational developments occur in the Tagaqa, Hideway, and Natavora Domains. The mountain archetype is broken down into subarchetypes on the basis of tropical forest (fo) cover and scrub (sr) vegetation, except in the Hideway Domain, where terrestrial forest vegetation dominates, as shown in the code M_fo. Although narrow perched beaches less than 10 m wide occur in the eastern part of the Black Rock Domain, they are not noted in the cross-shore codification due to the widespread occurrence of rock and dead coral alongshore.

This 3095-m-long coastal belt (Table 4), which lies about 2.5 km downslope of the mountain Balenabelo village (Figure 4), is comprised by five fringing reef domains (Komave, Natewa, Tambua, Namada, and Baravi) that are respectively 465, 580, 570, 820, and 660 m long. The eastern and western distal ends of this fringing reef coastal belt are characterized by deep-water shore-perpendicular channels in the Komave and Baravi Domains. Classification of coastal plan-view configuration in the vicinity of the channels was arbitrarily classified on the basis of the position of the thick red line marking the boundary of the coastal belt to produce embayed (configuration number 4) and leiomorphic (configuration number 7) fragment designations (see Table 1). The Tambua and Namada Domains, which together comprise 45% of CB4, differ from one another in that the former retains a small delta, as does the Natewa Domain. Cross-shore catenary sequences show Cr-F-Be-M (Coral Reef-Flat-Beach-Mountain) tetrasequent (Komave and Baravi Domains), Cr-F-De-Be-M (Coral Reef-Flat-Delta-Beach-Mountain) or Cr-F-Be-Dv-M (Coral Reef-Flat-Beach-Developed-Mountain) penta-sequent (Natewa and Namada Domains), and Cr-F-De-Be-Dv-M (Coral Reef-Flat-Delta-Beach-Developed-Mountain) hexasequent (Tambua) archetypical catenas. Onshore commercial developments are associated with Tambua and Namada Domains, as shown in their respective cross-shore codifications: 7Cr_fr,paF_saDeBe_caDv_coM_fo,sr and 7Cr_fr,paF_saBe_caDv_coM_fo,sr.

This 4650-m-long coastal belt (Table 5), which lies in the vicinity of the beach-front Vatukarasa village (Figure 5), is comprised by five fringing reef domains (Vatukarasa, Balenabelo, Sovi, Vuavua, and Natewa) that are respectively 1163, 820, 1367, 890, and 410 m long. The Vatukarasa and Sovi Domains, which take up 2.53 km of alongshore distance, comprise 54% of CB5. This coastal belt centers on Sovi Bay, which makes up the Sovi Domain, and it is bounded to the east by a large embayment that comprises the Vatukarassa Domain. The deep-water channel separating the fringing reefs and leading to Sovi Bay is about 530 m wide, whereas the channel to the east in the Vatukarassa Domain is about 470 m wide. These embayment domains show typical cross-shore catenary associations with a basic trisequent Cr-Be-M (Coral Reef-Beach-Mountain) archetypical codification, except in the case of the Vatukarassa Domain, where there is commercial onshore development to produce a code sequence of 4Cr_fr,paBe_caDv_coM_fo,sr. Although similar to the tetrasequent Cr-F-Be-M (Coral Reef-Flat-Beach-Mountain) archetypical sequence for the Balenabelo and Natewa Domains, the Vuavua Domain retains a small delta at the mouth of a mountain stream as recognized in the following alphanumeric cross-shore pentasequent codification: 7Cr_fr,pa F_saDeBe_caM_fo,sr. Fringing coral reefs occur on the flanks of the embayment channel margins, with occasional patch reefs being associated with shallower waters near the bay heads and hence the subarchetype classification Cr_fr,pa and shoreline configuration numerical code 4 (Table 1). Reef-front morphological configurations tend to be leiomorphic.

With an alongshore distance of 5703 m (Table 6), CB6 (see Figure 1) is the longest stretch of continuous fringing reef in the study area (Figure 6). Its eastern and western margins are demarcated by embayments with an eastern deep-water channel about 175 m wide and a slightly narrower 120-m-wide channel to the west (boundary between CB6 and CB7). A small intrareefal embayment occurs about 250 m southeast of the Korotogo shore and intervenes on the marginal channel boundaries where the deep-water channel is only about 50 m wide at the surf break. The Bedarra (also partly shown in Figure 7) and Korotogo Domains comprise 59% of CB6, with the Naroro and Tubakula Domains accounting for 34% of the fringing reef archetypical zone. Shoreline configuration at the reef fronts tends to be leiomorphic (numerical code 7, Table 1), except where there are domains containing deep-water channels (i.e. Naroro, Kula, and Bedarra). The basic archimorphic Cr-F-Be-M (Coral Reef-Flat-Beach-Mountain) tetrasequent archetypical catenary sequence, as shown for the 425-m-long Kula Domain, expands to penta- and hexasequent catenas when delta or developed subarchetypes are present alongshore, as occurs respectively for Tubakula Domain (7Cr_fr,paDeBe_caDv_coM_fo,sr), Korotogo Domain (7Cr_fr,paF_saDeBe_caDv_reM_fo,sr), and Bedarra Domain (4,7Cr_fr,paF_saDeBe_caDv_reM_fo,sr) cross-shore codifications. CB6 displays four delta archetypes that build seaward over the back-reef flat in the Naroro, Tubakula, Korotogo, and Bedarra Domains. The greatest seaward extent of the delta archetype occurs in the Korotogo Domain, where the stream-fed alluvial apron extends about 100 m from the shore. Commercial and residential developed subarchetypes occur in the Tubakula, Korotogo, and Bedarra Domains, where the main anthropological activities focus on servicing the tourism industry.

This 3333-m-long coastal belt (Table 7), which lies in the vicinity of the beach-front Olosara village that also fronts the Sigatoka River (Figure 1), is comprised by four fringing reef domains (Alasa, Olosara, Sigatoka, and Yadua) that are respectively 545, 1194, 680, and 914 m long. The western margin of the CB7 fringing reef (Figure 7), which occupies the eastern part of the image, lies at the mouth of the river about 3.5 km downstream from the town of Sigatoka. A river beach archetype, with a dry beach width up to 125 m wide, lies in the lee of the western distal margin of the fringing reef subarchetype (Cr_fr). The shore in the western half of the satellite image is comprised by sedimentary subarchetypical features such as onshore compositionally mixed sandy beaches (Be_ca,si) and spits (Ba_bi), dunes (Du) with upstream fluvial meander belts, oxbow cutoffs, and wetlands (W_ma) (cf. Table 1). The dune archetype is undifferentiated. The east bank river beach is about 600 m long, and the seaward fringing reef is about 1.3 km long from the river to the deep-water channel that separates CB6 from CB7. The shore configuration in plan form is mostly leiomorphic, except in the case of the eastern embayment, which receives a numerical code of 4 for curved bays (Table 1). Developed subarchetypes include recreational facilities onshore in the Alasa Domain, whereas in the Olosara Domain, agricultural enterprises are dominant, as reflected in the respective codes Dv_re and Dv_ag. The other main difference between these two fringing reef domains is the presence of onshore igneous rock outcrops on the landward margin of the reef. The resulting Cr-F-R-Be-Dv (Coral Reef-Flat-Rock-Beach-Developed) pentasequent codification expands to the following subarchetype cross-shore catena: 7Cr_fr,paF_saR_igBe_caDv_ag. The Sigatoka and Yadua Domains are characterized by sandy barrier (Ba), beach (Be), and dune (Du) archetypes with no coral reefs. Mobile dune subarchetypes in the Yadua Domain contain sections that have blowouts, while others are forested, to produce the codified designation Du_bo,mo,fo.

This 4113-m-long coastal belt (Table 8) lies in the vicinity of the coastal Yadua village (Figure 1) on the flanks of the Sigatoka Sand Dunes National Park (east side of image in Namuka and Naduri Domains). The eastern half of this satellite image (Figure 8) features sandy beach and dune archetypes that comprise alongshore lengths of 1295 m (Namuka Domain) and 1235 m (Naduri Domain), while the western half is comprised by two fringing reef domains (Venatovau and Tavuni) that are respectively 837 and 746 m long. The archetypical cross-shore catenary sequences in the eastern part of the image are archimorphic Be-Du-Dv (Beach-Dune-Developed) trisequent catenas, except for the Naduri Domain, which includes an inland mountain archetype (M) on the landwardmost part of the transect, bringing the curved shore tetrasequent subarchetype codification to 2Be_caDu_bo,mo,foDv_ag,reM_fo,sr. Developed subarchetypes are found in both domains on alluvial plains and dune flats. The fringing reef is bounded by deep-water channels, of which the western channel is the larger at about 140 m across compared to the 50-m-wide eastern channel. Similar to other fringing reefs along the Coral Coast study area, this reef is divided into domains. The hydraulic jumps in the western Tavuni Domain suggest somewhat shallower water than the eastern Venatovau Domain. The cross-shore domainal boundary is laid through an incipient tidal channel as a basis for an oceanward separation, while beach and delta archetypes differentiate onshore portions of the transects in the Venatovau and Tavuni Domains. Coastal configuration in plan view in the Venatovau Domain is curvilinear (scoliomorphic), while the Tavuni Domain exhibits a leiomorphic oceanfront and channel flank shape. The domainal boundary also separates sediment deposition patterns that emanate from the western tidal channel, which differentiates CB8 from CB9 and shows seaward backflow from inshore toward the center of the reef flat. A mirror pattern occurs to the east in the Venatovau Domain to produce a confluence of sand encroachment on the reef flat. From the reef front to the shore, the Venatovau Domain shows a Cr-F-Be (Coral Reef-Flat-Beach) trisequent catena, whereas the Tavuni Domain carries a Cr-F-De trisequent catenary association. The respective Venatovau and Tavuni coral reef domains expand to full subarchetypical catenas as follows: 2Cr_fr,paF_sa,tcBe_caDv_agM_fo,sr and 7Cr_fr,paF_sa,tcDeM_fo.

This 2962-m-long coastal belt (Figure 1; Table 9), which lies on the eastern margin of the Maleqereqere Pass (Figure 10) and 3.7 km east of Cuvu Beach (CB9), is comprised by three fringing reef domains (Gecko, Kokomea kava, and Cuvu) that are respectively 360, 1042, and 1560 m long. Fringing reef development on the eastern margin of CB9 in the Gecko and Kokomea kava Domains is separated from CB8 by a shore-perpendicular deep-water channel that is about 140 m wide. The reef flat in this zone is about 820 m wide, based on the maximized distance between the beach and the reef front. By comparison, the width of the fringing reef in the Cuvu Domain is about 280 m wide. As far as archetype designations are concerned, the Gecko Domain is the most complicated with a cross-shore catenary association codified in terms of a Cr-F-DeBe-Dv-M (Coral Reef-Flat-Delta-Beach-Developed-Mountain) hexasequent catena and a subarchetypical alphanumeric catena4,7Cr_fr,paF_sa,tcDeBe_caDv_reM_fo,sr that identifies embayed and leiomorphic plan views of the coastal configuration. The tidal channel heads in a delta that is fed by sedimentary load from a mountain stream. Deltaic tidal flats extend about 200 m seaward of the inlet mouth. Developed subarchetypes in the Gecko Domain are dominated by residential components of beach-front villages, whereas a combination of agriculture and residential categories occurs in domains to the west. Transect codification for the Kokomea kava and Cuvu Domains is almost identical except for the notation of a boundary tidal channel cutting across the reef in the Cuvu Domain, separating it from CB10.

This 3975-m-long coastal belt (Figure 1; Table 10), which lies between the large embayment of Cuvu Harbour to the west and Maleqereqere Pass to the east (Figure 10), is comprised by four fringing reef domains (Maleqereqere, Navovo, Vunamoli, Takali) that are respectively 412, 1038, 920, and 1605 m long. The landward margins of tidal channels demarcating CB10 are fed by freshwater mountain streams. Voua village lies on the western margin of the study area, which is demarcated by the B-B′ boundary line (Figure 10). Perched beaches occur in all four domains but are especially poorly developed in the Takali and Vunamoli Domains, where there are frequent carbonate rock outcrops. The sandy flat archetype is most fully developed in the Navovo Domain, where there is a maximum cross-shore distance of about 950 m between the beach and broadly curvilinear reef front in plan view. The fringing reef is about 730 m wide in front of Shangri-La Yanuca Island (Figure 10), which is surrounded by flat archetypes. The island per se is codified as a developed (Dv) archetype, with residential development (including a golf course and other modest tourism facilities) codified as Dv_re. Cross-shore codifications of the Maleqereqere, Navovo, and Vunamoli Domains are basically similar with the archimorphic mnemonic Cr-F-Be (Coral Reef-Flat-Beach) catenary sequence, which is commonly followed landward by the disequent Dv-M (Developed-Mountain) catena, which in turn, in the case of these three domains, expands to Dv_reM_fo,sr (residential development and forested mountains and scrub vegetation) subarchetypes. Due to the presence of a small sandy delta in the Vunamoli Domain, the complete hexasequent codification is 4,7Cr_fr,paF_sa,tcDeBe_caDv_reM_fo,sr, as a deviation of the archimorphic Cr-F-Be catena. The delta sensu stricto extends about 45 m offshore, overriding the reef flat, but its freshwater sphere of influence extends about another 30 m offshore. The alongshore stretch of the delta is about 200 m.

The eco-geomorphological units and anthropogenic features, which are identified in cross-shore transects as archetypes and subarchetypes, on part of the Coral Coast of Fiji were inspected in terms of their frequency of occurrence and spatial distribution patterns. Classification of the coastal belts was based on the identification of specific types of cross-shore catena sequences that had alongshore spread and were identified in terms of domains. Cross-shore catenas and domains were inspected relative to the coastal belts where they occurred. Overarching spatial relationships are referenced to Figure 1, which provides an overview of the study area coastal belts, whereas details concerning specific transectal domains are referred to respective figures and tables numbered 2 through 10. This analysis was conducted by interpretation of satellite images and some collateral data. For ease of description, morphometric properties were organized according to codified archetype and subarchetypes, for example, in terms of fringing reef (Cr_fr), patch reef (Cr_pa), carbonate beach (Be_ca), developed commercial and residential facilities (Dv_co,re), and mountain vegetative cover (M_fo,sr) subarchetypes (cf. Table 1). The Delta archetype is undifferentiated and simply identified as De without further breakdown.

Morphometric analysis of the fringing coral reef distribution patterns as well as consideration of configuration in planview provided some visual clues as to the nature of this tropical island coast, which is characterized by fringing coral reef subarchetypes, a subdivision of the coral reef archetype (Cr). The archimorphic fringing reef flats, which support the development of the patch reef subarchetype (Cr_fr,pa), initiate all cross-shore catenary sequences. Fringing reefs in the Coral Coast study area span an alongshore distance of about 32 km. The fringing reefs are segmented into nine coastal belts (CB) (Figure 1), which are discrete and contiguous eco-geomorphic units that averaged about 3978 m in alongshore spread with lengths ranging from 1892 m (CB2) to 5703 m (CB6). These coastal belts were in turn subdivided into 35 domains based on the codification of cross-shore transects that recognized sequences of coastal archetypes. Most fringing reef tracts were subdivided into 4 (CB2,7,8,10) or 5 (CB3,4,5,6) archetypical and subarchetypical domains (Tables 2 through 10), except for CB9, which featured three domains along 2962 m of shore, giving an average reef tract alongshore spread of 987 m within the range 360 m (Gecko Domain) to 1560 m (Cuvu Domain) (Table 9).

Perhaps not surprisingly, based on the data in Tables 2 through 10, the longest average alongshore spread of the fringing reef archetype (1140 m) was found in the longest coastal belt (CB6 at 5703 m) (Table 6). Dividing the total length of the fringing reef alongshore spread of 32 km by 35 domains works out to about 915 m per domain. In other words, fringing reefs along the Coral Coast averaged about 1 km in alongshore spread, with segments separated by deep-water shore-perpendicular channels that headed in freshwater river mouths, some of which carried enough sediment to form sandy deltas that overrode the reef backshore. This average alongshore length of a coastal belt is conceptual and provided as an aide to visualization of reef tracts on the Coral Coast that are separated from one another by deep-water channels.

Based on visual inspection of the satellite images and measurement with the ruler tool in Google Earth Pro, the cross-shore widths of the fringing reef (Cr_fr) subarchetype averaged about 600 m, including maximum and minimum seaward extents from the reef front (breaker lines) to beach (Be_ca) subarchetypes. Examples of relatively wider reefs occurred in CB2 (750 m), CB9 (840 m), and CB10 (950 m), with somewhat narrower fringes occurring in CB4 (420 m) and CB5 (240 m). Less than half of the shoreline length in CB7 and CB8 was occupied by fringing reef (Cr_fr), with carbonate sandy beach (Be_ca) archetypes accounting for the remainder in the vicinity of the Sigatoka River outlet and the Sigatoka Sand Dunes National Park.

Patch reef (Cr_pa) subarchetypes are scattered about the reef flats in variable patterns and clusters. In some cases, patch reef spatial distribution patterns reflect curvilinear water flow patterns in the vicinity of deep-water channels heading at river mouths, as shown for example at channel boundaries between CB3 and CB4, between CB9 and CB10, and in the center of CB5 (margins of Sovi Bay). The distribution of patch reef archetypes also frequently tends to follow rubble striations on the reef flats and was particularly pronounced in CB2, CB3, CB6, CB9, and CB10.

Approximately 12 delta archetypes (De) are scattered along the shore of the Coral Coast study area and occur in the following coastal belt domains: CB2 (Lomani Wai Domain), CB3 (Tagaqa, Natavora, and Undu Creek Domains), CB4 (Natewa and Tambua Domains), CB5 (Vuavua Domain), CB6 (Naroro, Tubakula, Korotogo, and Bedarra Domains), CB9 (Gecko Domain), and CB10 (Vunamoli Domain). The delta archetype is undifferentiated due to the large scale of the satellite imagery, and even when zoomed, these eco-geomorphological features show a small footprint in the coastalscapes.

Delta archetypes (De) are distributed at the mouths of mountain streams that issue onto back-reef areas. The fluvial sands are thus overriding the back reefs being deposited on top of a mostly dead coral platform. The morphometrics of the small delta archetype in the Lomani Wai Domain (CB2, Figure 2), for example, measure about 50 m cross-shore and 130 m alongshore. Similar morphological shape parameters in plan view were obtained for the fluvial delta on the eastern margin of the Korotogo Domain (CB6, Figure 6), where the cross-shore extent is about 90 m, and the alongshore spread is 170 m. Although it is the largest delta in the study area, the delta archetype at the mouth of the Korotogo River is submerged where it enters deep water and is asymmetrically deflected downdrift to the west. As near as can be ascertained from the satellite image shown in Figure 6, the deltaic sands extend about 665 m offshore and approximately 1200 m alongshore. Fluvial sands comprising the delta at the head of a deep-water cross-shore channel in the Gecko Domain (CB9, Figure 9), by way of another example, are characterized by a cross-shore extent of about 200 m and an alongshore spread of about 250 m. The shape of the delta is constrained by the shoreline configuration and morphometry of fringing reef channel margins.

Finally, the small delta archetype (De) shown in Figure 10 in the center of the alongshore spread of the Vunamoli Domain (CB10) shows patch reef (Cr_pa) development around the seaward perimeter of fluvial sand splays over the back reef, extending about 70 m offshore and over a shore-parallel extent of about 170 m. From a compositional point of view, the fluvial sands comprising deltaic developments that override back-reef flats would be composed of siliciclastic materials that reflect the volcanic nature of the island's interior lithologies. The delta sands would thus presumably contain admixtures of carbonate and noncarbonate materials.

The carbonate beach (Be_ca) subarchetype (a subdivision of the beach archetype [Be]) is present, to varying degrees, in each coastal belt. Beaches tend to be very narrow (<10 m) and perched over a limestone substrate. The carbonate beach sediments are dominantly composed of reef fragments, and this archetype thus tends to be of poor quality on a general rating scale of world beach types. Along the Coral Coast, the beach subarchetype is best developed in the vicinity of delta archetypes and river mouths, as shown for example in CB2, 3, 5, 6, and 10, with the best examples occurring in CB7 and CB8, where there are plentiful siliciclastic fluvial sands from the Sigatoka River. The sands derived from the Sigatoka River are sufficient to produce beach and dune archetypes where dry beach widths may reach 40 m in width, with low backbeach dunes up to 2 m or so in height. Most dry beach widths average less than about 10 m, except in the vicinity of small fluvial deltas, where they can exceptionally range somewhat wider, as in CB6, where they reach 15–18 m near Korotogo.

The developed archetype (Dv), as described in Table 1, refers in part to agricultural lands, residential neighborhoods, and commercial sites as seen on these tropical mountains and coastal footslopes. These categories remain undifferentiated in this study with the subarchetype designators Dv_ag (agricultural land uses), Dv_co (commercial enterprises), and Dv_re (homes, communities, settlements, villages, etc.), which were used to indicate the nature of the inland coastal environment, as interpreted from the satellite imagery. These subarchetype codes typically occur as the penultimate member in the cross-shore catenary sequences as follows: Dv_ag in CB2 (Shambala Domain, Table 2), CB7 (Sigatoka Domain, Table 7), CB8 (Namuka, Naduri, and Venatovau Domains, Table 8), and CB9 (Kokomea and Cuvu Domains, Table 9); Dv_co in CB3 (Hideway Domain, Table 3), CB4 (Tambua Domain, Table 4), CB5 (Vatukarasa Domain, Table 5), and CB6 (Tubakula Domain, Table 6); and Dv_re in CB2 (Shambala Domain, Table 2), CB3 (Tagaqa Domain, Table 3), CB6 (Korotogo and Bedarra Domains, Table 6), CB8 (Naduri Domain, Table 8), CB9 (Gecko, Kokomea, and Cuvu Domains, Table 9), and CB10 (Maleqereqere, Navovo, Vunamoli, and Takali Domains, Table 10). Examples of Dv_co and Dv_re categorized areas are broadly indicated in Figure 1, where the following are shown from east to west along the Coral Coast: Tagaga (CB2), Vatukarasa (CB5), Korotogo (CB6), Olosara (CB7), Sigatoka (upstream from CB7), Yadua (CB8), Cuvu (CB9), and Voua (CB10). Most of the Coral Coast is largely undeveloped in the big scheme of things, and consequently the Dv archetype does not occupy a prominent or dominant aspect of the Coral Coast coastal belt study area.

The mountain archetype (M) occurs as the ultimate code in most every domain, with exceptions in CB7 (Alasa, Olosara, Sigatoka, and Yadua Domains, Table 7), CB8 (Namuka Domain, Table 8), CB9 (Kokomea and Cuvu Domains, Table 9), and CB10 (Takali Domain, Table 10). These exceptions result where there are alluvial plains seaward of mountain footslopes (CB7, 8, and 9) or sedimentary accumulations on back-reef areas (CB10). In all other domains, the mountain archetype is featured as the last code in the cross-shore catenary sequence. In all cases, forest and scrub subarchetypes (cf. Table 1) are designated as occurring within the width of the coastal belt inland, where some residual (unlogged native stands) tropical moist (ER622) or dry (ER635) tropical forest occurs in association with cleared land that is now in scrub vegetation. Rare exceptions occur in CB3 (Hideway Domain, Table 3) and CB8 (Tavuni Domain, Table 8), where only the M_fo subarchetype (forested mountain category) predominates as the dominant land use.

The purpose of this research experiment, based on transectal cross-shore codifications, was to ascertain the efficacy of the BCCS (Biophysical Cross-shore Classification System) for describing a tropical coral reef coast that is characterized by fringing reef subarchetypes. A dominant-feature approach, as commonly found in other coastal classifications outside of the BCCS scope, might be to essentially classify the southern shore of Viti Levu simply as a coral coast. The specificity of this kind of generic approach is suitable for many purposes and may be quite adequate for alongshore characterization of the coast in terms of the presence of a coral reef eco-geomorphic setup (Finkl, 2004; Makowski, 2014; Makowski and Finkl, 2016; Makowski, Finkl, and Vollmer, 2015, 2016, 2017).

The BCCS, on the other hand, goes beyond characterization of the immediate shore by reference to the nature of onshore (inland) eco-geomorphological and anthropogenic development. This more comprehensive approach is accomplished by constructing cross-shore transects that codify natural and artificial features from seaward to landward positions in terms of sequential units that are linked in the form of catenary associations. The shorthand notations that abbreviate various types of designators, as summarized in Table 1, characterize cross-shore sequences that have alongshore spread (Finkl and Makowski, 2020a,b,c,d). This dual approach thus provides a characterization of coastal belts, which comprise the coastal zone and adjacent terrestrial (land-based) properties. The alongshore spread of cross-shore catenas achieves spatial recognition in the form of domains (Finkl and Makowski, 2021a,b,c, 2022a) that make up coastal belts. In this way, coastal segments are described in terms of alongshore swaths that have cross-shore widths from variable distances offshore to onshore depending on the nature of natural and artificial features that are desired to be recognized and classified (Finkl and Makowski, 2021c, 2022a).

This discussion briefly considers some advantages of this dual approach to coastal classification as well as indicating some inherent difficulties or pitfalls in the approach. No system of coastal classification is perfect, foolproof, or comprehensive to the point that everything can be included because the process is scale dependent, and, in the case of the BCCS, the classificatory procedures rely on interpretations of satellite images. Additionally, most coastal classifications are designed for special purposes that focus, for example, on engineering works, geological or geotectonic frameworks, landforms, coastal processes, biological characteristics, military applications related to amphibious landing sites or trafficability, and managerial or administrative designations, among others. As the BCCS is a special-purpose approach to coastal classification that is based on the recognition of transectal sequences from offshore to onshore, a coast with substantial development of fringing reef subarchetypes was selected to test or consider cross-shore and alongshore diversity and similitude.

Codification of the fringing reef subarchetype in the BCCS uses the Cr_fr designator, and this code occurs in each domain along the Coral Coast study area. Because the patch reef subarchetype occurs in association with fringing reefs, the codification normally takes the form Cr_fr,pa for all domains except those where the coral reef archetype is not present, as in CB7 (Sigatoka and Yadua Domains; Table 7; Figure 7) and CB8 (Namuka and Naduri Domains; Table 8; Figure 8). Parts of these two coastal belts are exceptions along the Coral Coast due to the influx of fresh riverine waters along the shore and deposition of fluvially derived sediments that become distributed on the coast by longshore drift, where the abundance of sediment accumulates in the form of beach (Be) or dune (Du) archetypes. Although it is not possible to determine the compositional attributes of the sandy grain sizes from the satellite imagery, deductive reasoning indicates that most beaches are composed of comminuted carbonate particles that are derived from degradation of coral reefs, and consequently the beach subarchetypes were codified as Be_ca. In some cases, it would be logical to assume that beach sediments in CB7 and CB8 would be admixtures of carbonates and silicates and could thus be designated as Be_ca,si. Because this is an assumption, all beach subarchetypes were deemed to have high proportions of carbonates and so were designated simply as Be_ca. The situation is not problematic because ancillary or collateral data theoretically could be accessed to determine grain size compositions. Dickinson (1968) and Dickinson et al. (1998), for example, suggested that mineralogically complex sand delivered to the coast by the Sigatoka River is derived from a varied bedrock assemblage in the interior mountains composed of Tertiary sedimentary, metamorphic, and igneous rocks, with the latter contributing both volcanic and plutonic detritus.

Another example of a potential conundrum when interpreting eco-geomorphological features from the satellite imagery occurs along the western margin of the Sigatoka River. Complexity of the cross-shore catenary sequence codification is determined by the purpose or needs of the survey, scale, and ability of the operator to interpret the image scene. In this case, a relatively complex eco-geomorphological setup was recognized as dune field subarchetypes Du_bo,mo,fo (mixture of mobile dunes with blowouts and stabilized dunes with forest cover) and land use in terms of agricultural pursuits (Dv_ag). For the purposes of this experiment, this level of generalization was considered practical, but more detailed interpretations could be achieved for more specific purposes. A more complicated transectal sequence could be derived on the west side of the river, for example, by recognizing the presence in the Yadua Domain (Figure 7) of natural levees, crevasse splays, fans, and beach ridge complexes as described and mapped by Dickinson et al. (1998). Similarly, on the east side of the river, a delta plain could be recognized in the Sigatoka and Olosara Domains (Figure 7), which was instead ignored in preference to the land-use designators Dv_ag,aq (developed agriculture and aquaculture) and U_fo (upland forest). This course of action was taken because the main purpose of the experiment was to codify the coral reef subarchetypes while including attendant terrestrial features and land use along cross-shore transects.

The nature of the fringing reef subarchetypes along the Coral Coast showed a high degree of similitude for the examples in CB2 through CB10. At the level of the BCCS, all of the reef segments between deep-water channels showed similar types of morphological development as described elsewhere, for example, by Dinerstein et al. (1997), Guilcher (1988), Nunn (1994), and Smithers (2011). Morphological features of the fringing reef subarchetypes not included in the generic codifications can be detailed in textual descriptions that could discuss the nature of pavement with sand and gravel covers; subdivision of outer ridge slopes, algal ridges, and sand fields; interpretation of wave dynamics and circulation patterns by reference to windrows and detrital sediment distribution patterns, and so on. Such detailed surveys of apron reefs could be conducted, but they were not the purpose of this investigation of cross-shore catenary sequences on a tropical reef coast.

Recurring typicalities in the cross-shore code sequences emphasize the relevance of recognizing archetypical catenas as, for example, in the case of the fringing reef eco-geomorphic units per se. The archimorphics point to the essence of the code designation Cr_fr,paF_sa,tc (fringing and patch reef environments with reef flats and deep-water channels) in every domain where coral reefs are present. Exceptions occur in CB7 (Sigatoka and Yadua Domains; Table 7; Figure 7) and CB8 (Namuka and Naduri Domains; Table 8; Figure 8), where the shore is dominated by barrier, beach, and dune archetypes. These exceptions are related to the freshwater and fluvial sediment input to the coastal belt by the Sigatoka River. Elsewhere, the common disequent code repetition Cr_fr,paF_sa,tc adequately characterizes the coastal marine portion of the Coral Coast. This codification of the Viti Levu southern shore coastal belt is so pervasive that it can be regarded as a shorthand designation for the region.

Variability in the cross-shore catenary associations occurs onshore in the landward parts of the codifications where there are volcanic rock (R_ig), developed (Dv_co,re, both commercial and residential), and mountain (M_fo,sr, both forest and scrub vegetation) subarchetypes. These variables are the result of disjunct spatial distribution patterns that bring a degree of complexity to the cross-shore descriptions. Depending on the requirements of coastal surveys, these examples of cross-shore classification can be expanded for more detailed investigations or narrowed to just the archimorphic (essential, chief, highest, most important eco-geomorphic feature) fringing reef eco-geomorphic disequent code Cr_fr,paF_sa,tc. The purpose of the BCCS is, however, to include onshore descriptors that provide a more complete impression of what a coastal belt is actually like by including categorization to several kilometers inland from the shore. Considering only the natural coastalscapes at a smaller scale than presented here, the entire study area marine recurring typicality would resolve to the tripartite shorthand notation Cr_fr,paF_sa,tcBe_ca, which identifies a fringing reef coast with reef flats and patch reefs backed landward by carbonate beaches that are subarchetypes of the Cr-F-Be (Coral Reef-Flat-Beach) trisequent archetypical code. Onshore codification tends to show mono- and disequent occurrence of developed (Dv) and mountain (M) archetypes. A typical whole-coast summary of the BCCS codification of archetypes might thus be a Cr-F-Be-Dv-M (Coral Reef-Flat-Beach-Developed-Mountain) pentasequent catena that extends from 500–600 m offshore to 1–2 km inland. Because the BCCS is an open-ended flexible classification system, there are thus numerous possibilities for adjusting or modifying code sequences to suite individual requirements.

By way of a final discussion point, it is perhaps worthwhile to mention the possibility of selecting the best imagery in Google Earth Pro using the history tool. In the case of this study along part of the Coral Coast of Viti Levu, an approximate 7 year span of acquisition dates (2010 to 2017) was utilized to achieve the most revealing imagery. Fortunately, scenes with different acquisition dates can be seamlessly stitched together, making selection of optimum spectral resolutions feasible. The experience is profitable because the alongshore continuity of multiyear image displays can be more or less normalized in terms of color coordination, providing an acceptable smaller scale (larger area) composite image set, as shown for example in Figure 1. This procedure is not required, but the history tool in Google Earth Pro provides opportunity of choice to produce aesthetically pleasing imagery sets over relatively long distances.

The south coast of Viti Levu in the Fijian Archipelago, South Pacific, was used as an experimental test site to determine the applicability of the BCCS (Biophysical Cross-shore Classification System) to detailed study of tropical fringing reef eco-geomorphic environmental setups at hectometric scales. Locally referred to as the Coral Coast, this coastal belt exhibited a range of natural and anthropogenic features that were codified as cross-shore catenary sequences in terms of coral reef (Cr), flat (F), delta (De), beach (Be), and mountain (M) archetypes. These archetypes were divided into subarchetypes by the presence of fringing and patch reefs to produce the reef concatenation Cr_fr,pa, and following in the same manner for reef flats with detrital sand covers and tidal channels (F_sa,tc); deltas were undifferentiated as simply De, carbonate beach sand composition was classed as Be_ca, and vegetative forest and scrub covers of tropical volcanic mountains were designated as M_fo,sr. Anthropogenic subarchetypes included commercial tourism developments and small residential villages, expressed as Dv_co,re.

The cross-shore codifications, which had alongshore spread, provided a basis for characterizing entire coastal belts from offshore to inshore to onshore manifestations. This complete or comprehensive view of coastal belts as a swath that includes marine, coastal, and terrestrial environments, as interpreted from satellite imagery, showed that coral reef similitude and onshore variabilities could be organized via application of the BCCS. Similar cross-shore catenas were used to define domains that had spatial context across-shore and alongshore that in turn exposed recurring typicalities that supported the concept of the archetypes and subarchetypes via cross-shore domainal catena sequences. A typical whole-coast summary of the BCCS codification of archetypes condenses to a Cr-F-Be-Dv-M (Coral Reef-Flat-Beach-Developed-Mountain) pentasequent catena that extends from offshore to the footslopes of tropical mountains. This study showed that because the BCCS is an open-ended flexible classification system, there is great potential for adjusting or modifying code sequences to meet specialized requirements of coastal classification, as in the case of the tropical fringing reef coastal belts in Fiji and coral coasts elsewhere.