The aim of the study was to define homogeneous environmental units, inside a land planning model. A multivariate analysis of a number of elements of the biophysical environment of the area and of its accessibility was carried out by preparing and processing digital maps. Sixteen homogeneous environmental units were determined. The criteria used in defining these units on the ground was firstly the geomorphology of the area; secondly the physical characteristics, using slope and aspect; and thirdly the hydrography, in terms of the presence and availability of water. It is concluded that the model used is appropriate for the zone under study, since it helps in delimiting the environmental units. Finally, multivariate techniques are recommended for the treatment of territorial variables.