The Dictionary of Human Geography

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display in pre-digitalgeography,fromexplana-

tory diagrams through the elaborate visual ren-

derings of the idealized landscapes ofspatial

scienceto the three-dimensional displays of

Torsten Ha ̈gerstrand’stime-geography. That

spatial-graphicaltradition has beenre-energized

through the development of Visualization in

Scientific Computing (ViSC), and now increas-

ingly incorporates relationships between concep-

tualandphysicalentitiesaswellasthree

dimensions (Turk, 1994). Visualization is now

widely accepted as a means of interpreting and

‘making sense’ of spatial patterns as part of a

revivified cartographic imagination within these

avowedly scientific streams of geographical

enquiry (cf. MacEachren, 1994).

geographic information systemscan be

understood as anontologyof that which

can be visualized. Visualization of spatial phe-

nomena is a delicate play between deductive

and inductive techniques, a subtle shift in

science that GIS promotes. Visualization pro-

vides a greater understanding, leads to effect-

ive causal variable identification and improved

hypothesisformulation, and results in more

reliable predictive relationships between vari-

ables (Anselin, 1988). Visualization supports a

wider range of collaboration and exploration

with less concern for mathematical rigour,

hypotheses testing and generality (Wright,

Goodchild and Proctor, 1997). Visualization

is a way of making quantitative approaches

less mathematical as it allows researchers to

work with a large number of variables. As the

number of variables increases, measures of

certainty are difficult to obtain and the analysis

becomes less mathematical. ns

Suggested reading

Slocum, McMaster, Kessler and Howard (2005).

von Thu

..

nen model A model for analysing

agricultural location patterns, based on the

pioneering work of a Prussian landowner.

Johann von Thu ̈nen (1783–1850) envisaged

a singlemarketfor farm products and sug-

gested that distance from that point would

be a prime determinant of both what was

produced where and therent(net profit) gen-

erated there. Based on this variable alone,

the model suggested a zonal land-use model

(see figure), on the assumption that farmers

produced the commodity on each tract of land

that would maximize their net returns.

Because of variations in the costs of transport-

ing different agricultural products, bulkier

and/or more perishable items are produced

closest to the market, where land rents are

consequently highest, leading to adistance-

decaygradient. Thisideal typearrangement

• also suggested for urban areas (cf.alonso
  model) – provides amodelagainst which real-
  ity can be compared, and can be modified to
  take account of variations in, for example, land
  productivity
  The von Thu ̈nen model was a central elem-
  ent in the promotion ofhuman geographyas a
  spatial science, in the context ofrational
  choice theoryanddecision-making. It was
  applied to land-use studies at a varietyofscales
  (e.g. Blaikie, 1971; Peet, 1969; Block and
  DuPuis, 2001); Barnbrock (1974: see also
  Ma ̈ki, 2004) pointed out that many have been
  very partial in their use of von Thu ̈nen’s ideas
  and fail to take account of his full project, which
  saw his model as anideal typeof a spatial
  arrangement thatwould emerge under a benign
  form ofcapitalism. Its means of simplifying
  the world in order to understand it has declined
  in relevance as transport costs have been
  reduced both relatively and absolutely, but it
  remains a valuable analytical framework. rj

Suggested reading

Chisholm (1979); von Thu ̈nen (1966 [1842]).

vonThu ̈nenmodel Land rent variations and

land-use patterns

Gregory / The Dictionary of Human Geography 9781405132879_4_V Final Proof page 803 30.3.2009 7:45pm

VON THU

..

NEN MODEL