PBL rapport 550026002 Calibration and validation of the land use ...

SImulated 2000 land use using discrete model
Figure 5.1
Observed 2000 land use (left) and its simulation with the discrete model, using 1993 land use as input (A) and the
multinomial regression specification (B) as input for the suitability maps
be explained by the fact that this attempt includes a partially
incorrect simulation of the land use that remains the same
(as was discussed in 4.1.2) and, in addition, will only simulate
a small part of the changed cells correctly. The latter may
be due to the fact that the applied logistic regression relies
strongly on land use in neighbouring cells. Therefore, new
urban developments are attached in the form of small rings
around current urban areas, producing compact urban forms
(Figure 5.1B). This process is intensified by the simultaneous
conversion of small open areas within the urban fabric. This
approach, therefore, is not well suited to simulate the development
of the large contiguous areas at specific, pre-defined
locations, which is the typical result of Dutch planning, as
discussed in Section 3. It is clear that these developments,
which so unmistakably follow the Dutch planning process, can
be simulated much better through the inclusion of specific
spatial planning maps. That agriculture and, to a lesser extent,
nature are simulated with a higher degree of correspondence
may partly be attributed to the fact these land-use types
typically cover large areas that can be captured, more easily,
with our methodology that stresses neighbourhood relations.
Another explanatory factor may be that the amount
of change in these categories relative to the area covered in
1993 (about 1% for agriculture and 4% nature) is fairly small,
compared to the urban and recreational types of land use (9
and 8%, respectively). Previous calibration efforts have shown
that models that predict little change generally perform
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Calibration and validation of the Land Use Scanner allocation algorithms