Geography Reference
In-Depth Information
and natural rock features. In addition a significant amount of information about land
use and feature attributes is conveyed by text. Such mapping has some success at
indicating the nature of disordered terrain, although in this case the use of a similar
design for symbols representing rough moorland rather confuses the terrain
portrayal.
Contemporary Ordnance Survey data is supplied in digital form and can there-
fore be portrayed at varying scales, and indeed with user-defined symbolisation.
The default portrayal shown in Fig.
2b
reveals that the combination of text and
mimetic symbolisation has been maintained on maps of this area captured
photogrammetrically and by GNSS survey update to archival material. The main
differences between Fig.
2a, b
are the reduction in sketching of spoil heap fea-
tures—the remaining cliff lines and rock faces on Fig.
2b
are mainly showing
natural features—and the concentration on point features. The areal depiction of the
area of mining is shown by a generalised pecked line surrounding the zone of
interest—this mainly outlines Zone B in the study described above.
Figure
2c
shows the influence of scale on landscape portrayal. It shows the
raster-scanned 1:25,000 mapping of the region which has been the focus of studies
here. In this case, the contour pattern does not fully reveal the dissected landscape,
and it is primarily text which offers, in a descriptive manner, the major clue to the
nature of the terrain.
It is clear that these map representations, like most topographic map products,
have had to sacrifice dimensionality, by graphically portraying the third dimen-
sion—a major factor in determining the disorder of a landscape—using
two-dimensional symbolisation. Techniques of symbolising the third dimension
have been developed and applied by cartographers for centuries. The contour line
has proven a most effective device for quantitatively communicating terrain data,
although an understanding of the whole terrain requires that contour lines be read as
a pattern. Further quasi-two-dimensional symbolisation can try to pictographically
portray terrain variability, the most obvious example being hill shading. Compar-
ison of Fig.
2d, e
using contour lines (1 m interval) combined with shaded relief of
the raster DSM to highlight terrain characteristics, re-iterates the differences
between Zones B and A, quantified above, and also shows the effectiveness of
such methods of representation in portraying disorder.
It is concluded here that map representation, which involves abstracting charac-
teristics and properties of the real world to cartographically transform spatial data
into a graphical product, inevitably sacrifices dimensionality. The representation of
three-dimensional surfaces using two-dimensional symbols is an obvious example.
The mapping of disorder requires a serious attempt at developing cartographic
symbols and map representations which can optimise the portrayal of multi-
Fig. 2 (continued) University of Edinburgh, Crown Copyright); (d) Extract from contour (1 m
interval) and shaded relief of the DSM in Zone B; (e) Extract from contour (1 m interval) and
shaded relief of the DSM in zone A
