Publication Date:
2015-03-31
Description:
Multifunctional artificial reefs (MFARs) have been growing in popularity over the last decade. They are offshore submerged structures which provide coastal protection while also enhancing marine and recreational amenities such as surfing and beach widening. A feasibility study was undertaken for São Miguel Island (Azores) where island-wide general site-selection criteria and local site-specific parameters identified São Roque reef as a potential MFAR location. Expert knowledge addressed multidisciplinary aspects through semi-guided interviews, which provided evaluation criteria for the São Roque reef development. Wave changes before and after reef reprofiling were determined using the Regional Coastal Process WAVE propagation model (CEDAS/RCPWAVE). Results demonstrated additional coastal protection to the historic church and existing seawalls, and no adverse effects on the updrift São Roque and downdrift Pópulo Milicias beaches. Further simulation for an extended reef (30 m seaward) showed model sensitivity together with a greater reduction in approaching wave heights. This analysis suggested that the further seaward the reef is extended, the greater the coastal protection afforded. It also denoted longer, rideable surfing waves and greater substrate surface area for marine colonization, while conversely having an increasing effect on downdrift Pópulo Milicias beach, construction costs and footprint impact. An optimal solution will provide a balance to these advantages and disadvantages. A SWOT analysis showed the potential of capitalizing internal strengths and external opportunities to offset internal weaknesses and external threats. With global growing emphasis on the importance of incorporating amenity values into coastal protection works, this research informs alternative solutions for other small islands, especially similar small volcanic islands.
Print ISSN:
0309-1333
Electronic ISSN:
1477-0296
Topics:
Geography
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