Drivers of island beach evolution: insights from an island‐scale study at Boa Vista (Cabo Verde)

Abstract

ABSTRACTBeach erosion poses significant threat to small island economies which are generally highly dependent on coastal tourism. This work investigates the evolution of the low‐lying sandy coast of Boa Vista through an integrated characterization of coastline and shoreline indicators (over the past four decades) based on aerial imagery. It was found that tandem use of the two indicators was important to obtain a reliable perspective of the Boa Vista low‐lying coastal evolution across a wide range of coastal environments. Results indicate that between 1968 and 2010 the coast was relatively stable, although some spatial variability was recognized. The largest changes were observed at the tips of embayed beaches and a clear coastal progradation was found at the southern (downwind) coastal sectors. Coastal evolution has been dominated by sediment budget and the results put in evidence the sedimentary connections between the beaches across the island, either through bypass and overpass processes. Findings show that understanding coastal evolution at low‐lying islands should be supported on island‐scale observations, being the only scale capable to capture the sedimentary connections between beach systems, that often control coastal evolution. © 2019 John Wiley & Sons, Ltd. © 2019 John Wiley & Sons, Ltd.