This pressure dataset is derived from three human activities datasets

- Urban land use (on land)

- Recreational boating and sports (updated layer for 2018 version, please see separate http://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/8c30e828-1340-4162-b7f9-254586ae32b6)

- Bathing sites

These data are described in more detail in separate fact sheets.

Urban land use data was first converted to 1 km grid cells and expanded with 1 km. Thus, coastal urban areas extended also to the sea. These areas were given value 1 and other sea areas, value 0.

Bathing sites (points) were converted to 1km grid and given value 1, rest of the sea areas were given value 0.

Normalized recreational boating data was converted to 1 km grid cells.

These three layers were summed to produce the layer (values from 0 to 3), after that the layer was normalized.

Hunting and recreational fishing data were excluded from human disturbance layer, as they are mostly reported per country and would have resulted in overestimation of the actual pressure.