Evaluation of shoreline change using optical satellite images

The aim of this work was to develop and evaluate a method which allows monitoring of shoreline change using optical satellite images. The large amount of people living close to the coasts, the extent of human modification of rivers and beaches, the climate change, and the episodic impact of storms. Makes crucial monitoring shoreline change to give guidance to policy makers and coastal scientists. Satellite images with a moderate resolution (<10m) are available since 70's and can cover 60km length. So, they can allow, in principle, the study of shoreline change covering large timescales and large geographical areas. To evaluate its capacity, first, a careful examination was carried out to determine which spectral band is best for shoreline detection. Second, different algorithms were studied to group the sea and the land. Third, the shoreline was linked to a known tidal datum. Given the tidal level, the inter-tidal beach slope and wave set-up, confidence bounds were determined for each identified shoreline. So comparison between different shorelines reveal true shoreline change.