Graph of grid squares and system of coordinates
The coordinate system used is the UTM, international ellipsoid, which has already been used in different European Atlases. The sample graph is based on a reticulate of grid squares of 2x2 Kms.
Each grid square is referred to by a letter (except for O), and a two digit number, preceded by a code related to the specific island (MAD, SEL, PST and DES), (MADD01), according to Figure 1:

Figure 1 – The reference of the grid squares 2X2 applies to the Northeast section of the Island of Madeira
Applying this grid over the totality of the territory of the Archipelago of Madeira would obtain a total of 291 grid squares. The grid squares 2X2 km are marginal if they include areas situated along the coast which have a lower useful terrestrial area to the 4 km2 of a grid square. In these situation the procedure to adopt will be defined at the location based on predefined standards (for more information contact This e-mail address is being protected from spambots. You need JavaScript enabled to view it )