Landscape can be divided in homogeneous pieces or areas called landscape units. The 
attributes that define this homogeneity depend on the scale of analysis. Traditionally, the 
landscape unit has been considered like a flexible tool that adapts to the different scales, 
objectives and characteristics of land. However, when the unit becomes a requirement asked by 
environmental legislation like in the Valencia Community, it seems necessary to define guiding 
principles that assure the consistency among the landscape units defined in different places.
The aim of this work is to search a set of criteria for landscape unit delineation at the different 
scales of analysis. It consists of two parts. Firstly, the main trends of the practical application of 
landscape unit definition in Spain are identified through the analysis of a sample of works. This 
part focuses on the extent of the study area, scale of analysis or resolution, geomorphology, 
land matrix and visual boundaries. The existing relationships among the variables are analysed 
with the aid of the Multiple Correspondence Analysis technique. Results show that although 
there are not shared criteria, a hierarchy in the way Spanish professionals are delineating 
landscape units can be derived from the comparison of their works. Hierarchy is more apparent 
in the attributes related to geomorphology and less obvious in the variables related to land 
matrix. Regarding visual boundaries, its role is not clearly defined. Generally, it is not commonly 
used in small scales related to national or regional extents.
Considering the results obtained in this analysis, the second part focuses on character or 
landscape structure at local scale. It is assumed that from the analysis of landscape structure in 
specific cases, a set of guiding principles can be inferred for landscape unit delineation. For this 
purpose, the municipality of Chiva (Valencia) is selected, an area with high landscape diversity. 
The main features considered in the analysis of landscape structures are type of landscape 
elements and combinations of these elements. This second feature is identified with the aid of 
quantitative landscape metrics that are calculated for two grids with different cell sizes (1 km2 
and 0,25 km2 ) and the multivariate analysis techniques: Principal Component Analysis, K-
means and Agglomerative Hierarchical Cluster. Results show the potential of this type of 
procedures for the objective identification of areas with homogeneous landscape structure. 
Considering the classification of structures in Chiva, we identify the factors that are responsible 
for the distinction of landscape types at local scale that can reiterate in other locations of 
Valencia Community.