CONTOUR LINES OF THE TERRAIN AND THEIR GENERALIZATION
Let us consider the contour lines of the Norwegian area, as depicted
on a topographic map, at scale 1:5.000 (figure 8).
NJ
N A
Figure 8. Contour lines of the topographic map 1:5.000, south-east
of Oslo, Norway. Redrawn from C.T.-031.5.1 Bredholt, Fjel-
langer Widerge A/S, 1964.
We notice that the contour lines have a much smoother appearance than
the profile of figure 5. Analysing the contour lines, we obtain an
average dimension D = 1.09, confirming our impression of a very smooth
curve. However, the selfsimilarity of the contours proved still pre-
served.
It is not quite obvious to us, why contours and profiles should have
such different roughness and different dimension, since they are
ideally just different intersections of the terrain with planes. But,
we must remember the effects of generalization on the contour line by
the cartographer, who represents the terrain smoother than reality,
but still selfsimilar in nature.
The selfsimilar behaviour of contours is usually intuitively maintained
in map generalizations. Figure 9, shows the spectra of shorelines of
Swedish lakes as computed from different map scales (Hàkanson, 1978).
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