Visualizing
a
Map of Walter Christaller, Poland 1941
Part II: Interpolation of the Benchmarked
Map
Sandra Lach Arlinghaus
Adjunct Professor of
Mathematical
Geography and Population-Environment
Dynamics
School of Natural Resources and Environment, The University of
Michigan, Ann Arbor
Please
set screen to highest
resolution and use a high speed internet
connection.
Please download the most recent free
version of Google
Earth®.
Make sure the
"Terrain"
box in Google Earth® is checked.
Download
the following file to use in Google Earth®
in addtion to the files from Part I:
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Christaller's 1941 map
of a plan for the settlement of western and central Poland was
brought
into Google Earth® in Part I of
this
article. The map was aligned with the globe using a set
of
benchmarks on the three highest levels of Christaller's
hierarchy. It remained to fill in the lower levels of
the
hierarchy on the Google Earth® globe.
The
sequence of images below does so.
The
strategy for
completing the task employs the use of "placemarks" directly
in Google
Earth® .
Placemarks are symbols that can be assigned location (x-y
coordinates)
and height. They are displayed in a "billboard" format
so they
always face the driver in the virtual reality scene. The
location
assigned to placemarks in Figure 1 are those from the
Christaller
map. The height given to placemarks is assigned by
number of
inhabitants from the legend in the Christaller map displayed
in Part I: a location to be
assigned 30,000
inhabitants is given a placemark anchored to the globe from a
height of
30,000 meters. All heights correspond directly to those
in the
legend of the Christaller map except the height for the
largest
cities: they are to have 450,000 inhabitants but were
given a
placemark height of 200,000 meters here to keep the symbol
within
visual range. In the sequence of images below, the large
blue
crosses represent cities to have 450,000 inhabitants; the
large red
crosses those of 100,000; and, the red crosses with yellow
outline
those of 30,000. These three top categories,
corresponding to
benchmarked places, also are labelled with target inhabitant
population. Below that in the hierarchy, places targeted
for 9000
inhabitants are marked with a red cross placemark outlined in
white;
those targeted for 3000 are marked with a yellow square; those
targeted
fro 1200 with a magenta square, and those targeted for 600
with an
evergreen tree. It is not necessary for the reader to
keep all
that in mind; the legend at the left in Google Earth® will remind
the
reader. Click on a category and a yellow box will find a
representative of that category in the map. Also, when
taking a
side-looking approach, the relative heights of the placemarks
coupled
with the Google Earth® legend will
help. Drive around in this landscape using the files
downloaded
at the top.

Figure
1. Placemarks interpolate benchmarks on the Google
Earth®
globe.
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Figure 2 shows a
side-looking view of Figure 1. Notice the different
heights of
the placemarks. Figure 3 shows a ground-level view of
the same
image. Notice that some of the tree symbols are
partially
obscured by variation in terrain.

Figure
2. Side-looking view of the map in Figure 1.
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Figure
3. Ground-level view of the image in Figure 1.
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It
was important to have the Christaller map superimposed on the
globe in
order to interpolate lower level central places among the
benchmarks. However, once the interpolation is complete,
the map
boundaries may interfere with visualising the landscape in
relation to
the placemarks. Figure 4 shows the entire set of
placemarks with
the map removed. Try recreating this picture using the
downloaded
files. Then, zoom in and drive around the virtual
reality
landscape.

Figure
4. Animation of placemarks. The
Christaller map has been
removed. Benchmark rods remain..
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The
benchmarks in Figure 4 may also interfere with a good view of
the local
landscape. Figure 5 shows a side-looking view of a river
valley
and placemarks, only. Load the files and recreate this
scene. Drive around and look at the fields, towns, and
cities of
Poland in relation to the placemarks representing
Christaller's choices
for settlements.

Figure
5.
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FOR
RELATED REFERENCES, PLEASE SEE THE SET AT THE END OF
PART I.
Solstice:
An Electronic Journal of Geography and Mathematics,
Volume XVII,
Number 2
Institute of Mathematical Geography (IMaGe).
All rights reserved worldwide, by IMaGe and by the authors.
Please contact an appropriate party concerning citation of
this
article:
sarhaus@umich.edu
http://www.imagenet.org