1 Spatial Modelling of the Terrestrial Environment - Georeferencial

222 Spatial Modelling of the Terrestrial Environment
Figure 10.11c shows the values of Moran’s I for built-form compactness within each
of the constellations. These display a similar overall spatial pattern to the corresponding
values for built-form area (Figure 10.10c). The absolute range of values for Moran’s I is
also similar (−0.37 to 0.34), with an overall mean and SD of 0.03 and 0.05, respectively,
such that most of the constellations exhibit a random spatial distribution of built-form
compactness values (Figure 10.11d). Only 12 of the constellations were found to exhibit
significant positive spatial autocorrelation (i.e., spatial clustering), of which eight also
exhibit spatial clustering in terms of built-form area (Figure 10.10d). The reasons for this
are thought to be the same as those outlined in the previous subsection, raised in the context
of built-form unit area.
10.6 Conclusion
In terms of the original objective of this study, the results are largely negative. In particular,
there is little evidence to suggest that a clear and unambiguous relationship exists between
the morphological properties and spatial disposition of built-form units within urban
constellations and the dominant land use that they represent. A number of reasons were
suggested to explain why this might be the case. First, and most importantly, constellations
defined and delineated in terms of closed loops of the road network frequently contain more
than one type of urban land use. The statistics calculated for the built-form units within such
constellations are, therefore, likely to be complex composites of their constituent land-use
categories. In other words, they may be thought of as defining a mixed structural class
whose properties overlap with those of the discrete land-use categories of which they are
composed. Second, and arising from the first point, it is possible that a clear relationship
nevertheless exists at some broader categorization of urban land use (e.g. residential versus
commercial/industrial). Evidence to support this assertion is provided by the fact that it
is possible to distinguish the hospital complex from the remaining constellations on the
basis of built-form unit packing and density. Third, but probably least likely, the structural
measures used in this study may not be the optimum ones to distinguish the types of land
use present in the scene concerned. Despite this, the built-form connectivity analysis employed
in this study has helped to provide a deeper insight into the spatial organization
of built structures within urban areas and has provided a means by which the morphology
of urban areas can be characterized at very fine spatial scales. In this context, one
could envisage extending the spatial and structural measures employed in this investigation
across the wider urban fabric to explore how they vary as function of constellation
contiguity.
Acknowledgements
The authors would like to acknowledge the support of the U.K. Natural Environment
Research Council through the provision of research grant number GR3/10186. The
Ordnance Survey digital map data are reproduced with kind permission of the Controller
of Her Majesty’s Stationery Office, Crown Copyright.