In the first two phases of EMODnet, the Seabed Habitats thematic project used a commercial software, namely ARCGIS^TM, to generate the broad-scale seabed habitat map, EUSeaMap. A key objective of phase 3 (2017-2021) was to develop a new GIS workflow that would be sound, repeatable and transferrable across sea regions, and to implement this workflow in tools based on open-source technologies. As a result, most of the workflow was implemented in the form of R scripts. For technical reasons, a small bit had to be implemented in the form of a ArcGIS^TM ModelBuilder model. These tools were used to construct the version 2019 and 2021 of EUSeaMap.

This technical guide is intended to help the reader learn how to use these tools. The vocabulary and concepts used in the document are defined and the GIS workflow is described. The purpose of the scripts is documented in detail, as well as what they require as input and produce as output. A step-by-step hands-on training is provided. However, it is important to note that this document is intended for advanced users, i.e. that a good knowledge of the methods used for EUSeaMap, which are described in other documents, is an essential prerequisite for understanding the document and the associated scripts.