Figure 2 - Biopermeability index on physiographic units
URBAN AND ENVIRONMENT SETTLEMENT PARAMETERS
Urban density (UD): this index can be implemented in different ways in relation with
the GIS data which are available on study area. In its easier form the index represent the
surface percent covered by builds in relation with the entire surface of the considered
spatial unit (mq/ha).
The significance of the UD index is directly linked to the urban sprawl and it is possible
to have further information if exist data on builds destination (residential, productive,
utilities, and so on), on the builds volume and inhabitants number (in this case could be
highlighted the extensive and intensive urban conditions).
The use of the UD index is particularly interesting on landscape units because there are
important relations between landscape kinds and settlement kinds in qualitative and
quantitative terms.