Danish coastal submerged aquatic vegetation 2018

Submerged aquatic vegetation (SAV) mapped with Copernicus Sentinel-2 MSI 10 meter imagery for the Danish coast. Mapping is based on images mainly from April/May 2018. Habitat classification categories are:  1: Unvegetated soft substrate (Sand); 2: Sparse vegetation; 3: Dense vegetation; 4: No data.

The map has been developed to capture SAV distributions at the national Danish scale and is less appropriate for local exploration. For a more detailed map of smaller regions, it is recommended to source a local map made with data and models specifically selected and trained for those areas, to ensure the highest level of detail and accuracy. The map shows "Submerged aquatic vegetation SAV" that is, seagrass + macroalgae (and possibly some mussels and stones here and there as well).

Note that for the satellite-based approach to be effective, the sea floor must be visible in the satellite imagery. Consequently, the achievable depth for mapping relies on environmental conditions such as cloud coverage, turbidity and water roughness. Typically, it is not possible to detect the eelgrass depth limits in Denmark with satellite imagery. To “see” as deep as possible, for the mapping spring images were used, as Danish waters tend to have better water quality at the beginning of the year, even though the vegetation can spread further during the growing season.

The categories “sparse vegetation” and “dense vegetation” do not cover a well-defined percentage coverage but are based on visual interpretation of satellite images and orthophotos.

Data portal for free download for private and non-commercial use: https://marine-vegetation.satlas.dk/

For more information visit

https://eo.dhigroup.com/projects/mapping_submerged_coastal_vegetation/

https://youtu.be/_xAa858qg70