Emerged seagrass and macroalgae

Algorithm description

This is a prototype product for a new Copernicus Service element which is being developed in the course of FOCCUS. The algorithm computes percent cover of emerging aquatic vegetation (seagrass and macroalgae) in intertidal regions of the German Bight based on temporal aggregates of the Normalised Difference Vegetation Index (NDVI). Sentinel-2 data are atmospherically corrected using sen2cor and pixels identified as water or clouds using IdePix are masked. Images are processed and aggregated using the Copernicus Data Space Ecosystem. Retrieved NDVI values are temporally aggregated per pixel around the time of maximum seagrass cover in July/August/September. Aggregated NDVI values are translated into vegetation percent cover based on an empirical relationship.

Limitations

Data availability depends on water level at the time of satellite acquisitions and cloud cover and may therefore vary spatially and temporally. The algorithm does not enable differentiation between different types of emerging aquatic vegetation (e.g., macroalgae, seagrass, diatoms) and does not consider vegetation health. This information would be subject of further development based on the delivered products.