Challenges and new strategies in assessing multidecadal shore platform sandy beach evolution from aerial imagery

The world's coastlines are dominated by rocky coasts, where embayed and shore platform beaches develop. The intrinsic characteristics of these environments make them extremely vulnerable to changes in oceanographic forcing. Assessing long-term beach evolution can be a challenging task because coastline indicators were developed for wide and low-lying sandy beaches. For example, as most shore platforms beaches are limited by a cliff or structure, they have a static landward boundary (coastline), thus inhibiting the use of any coastline indicator as a proxy of beach volume changes. Also, as shoreline position is highly dependent on short-term sea-level fluctuations, the use of shoreline indicators is frequently subject to high uncertainty.