Island morphology, reef resources, and development paths in the Maldives

Abstract

Maldivian paths for economic development have historically been constrained by the morphology of atoll islands and the availability of material resources. These constraints are most evident when examining the development of Male’, the Maldives’ capital and most populous island. Before the 1970s, Male’ was a rather typical atoll island, consisting of accumulated rubble and sand with an underlying lagoonal reef (faro) structure. Rising population and standard-of-living expectations in Male’ led to accelerated coral mining of Male’s reefs in the 1970s and 80s for both landfill and construction material, extending the island’s land surface across Male’s lagoon and reef flats, close to the edge of its underlying faro. This combination of mining and fill degraded the island’s natural defenses against wave events, resulting in disastrous floods in April 1987 and the fortification of the coastline with seawalls shortly thereafter. The degree of degradation to natural defenses and amount of investment in urban building stock have jointly locked Male’ into a “hard path” for coastal resilience engineering, and both the damage patterns and response to the 2004 Indian Ocean tsunami demonstrate that the Male’ model of development and degradation has spread to smaller Maldivian islands. While hard measures have proven successful in preventing further damage, their expense has led to greater interest in “soft path,” ecosystem-based resilience measures. The degree of local ecosystem damage, combined with high vulnerability to climate change and Male’s continued growth, means that such measures can only be seen as supplements to heavier fortification in the future, including raised (Th. Vilufushi) or artificial islands (Hulhumale’). The intersecting role hydrological stress on Maldivian groundwater has played in Male’s development path is also discussed.

Observations on the Concept of the Aquapelago Occasioned by Researching the Maldives

“…When the Indian subcontinent met the Asian plate, it slowed down and the volcanoes slowly subsided into the sea, leaving fringes of upwardly growing coral reefs that built up over centuries to form atolls. Today atoll rims surround coral-floored basins 25-50 m deep rising towards their edges and dropping off steeply to the surrounding ocean floor to depths of 2500-4000 m (Naylor, 2015). The tops of these cones mark the ancient fringes of now submerged volcanic peaks to form the slender corridor of twenty-six atolls that make up the Maldives (Figure 1).…”

“…Many Maldivian reefs are in this so-called catch up mode at present (Naseer, 2006). Unless checked, these changes could accumulate and result not only in the deaths of polyps and algae, reef systems and fish, but the entire Maldivian civilization (Naylor, 2015).…”

Contrasting potential for nature-based solutions to enhance coastal protection services in atoll islands

“…The latter were found to be a major controlling factor of island change, not only in atoll capitals, e.g. Male' in the Maldives (Naylor, 2015), South Tarawa in Kiribati (Biribo & Woodroffe, 2013;Duvat, Magnan, & Pouget, 2013), and Fongafale in Tuvalu (Yamano et al, 2007), but also in rural and even in unsettled islands Duvat, Salvat, & Salmon, 2017). In most cases, human-driven changes mainly consisted in land reclamation, carried out to face land shortage, and in coastal infrastructure (airport and harbour) development (Duvat, Salvat, & Salmon, 2017;Duvat, 2019).…”

“…This is all the more so as most coastal protection structures are poorly designed and maintained, even in urban islands (Shaig, 2011;Duvat, 2013). Male', which is protected by emerged breakwaters and massive rock revetments along most of its shoreline (Naylor, 2015), is the exception. In atoll environments, the use of hard defence significantly also contributes to the degradation of the reef ecosystem, because the material used to build protection structures is often directly extracted from nearby reef flats and beaches (Biribo & Woodroffe, 2013;Duvat, 2013), while also undermining the capacity of islands to naturally adjust to ocean-climate related pressures through sediment reorganisation by obstructing reef-to-island sediment transport pathways (McLean & Kench, 2015;Duvat, 2019).…”

“…While especially true for capital areas that benefited from international aid-fundinge.g. in Majuro (Ford, 2012), the South Tarawa Urban District (Duvat, 2013), and Male' (Shaig, 2011;Kench, 2012;Naylor, 2015) these options were also widely deployed in outer, rural islands. The poor design and maintenance of most of these structures (Kench, 2012;Duvat, 2013), however, limited their benefits in terms of better protecting island communities and lowering coastal risks.…”