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

Simulated 1993 land use using discrete model Figure 4.1
Observed 1993 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.
4.2
Continuous model
4.2.1 1993 land use as input
To use the 1993 land use as input for the continuous model,
the per-cell suitability value of each land-use type is specified,
as the natural logarithm (ln) of the area claimed by that land
use in that particular cell. This definition corresponds with
the original algorithm described in Section 2.1. The approach
leads to an exact representation of the 1993 land use (Table
4.1), showing that the continuous model, just as the discrete
model, is working properly. The map resulting from these
simulations (Figure 4.2A) also shows this correspondence.
Please note that two different types of comparison are used
for the continuous model. The first type compares maps of
dominant land-use, for both observed and simulated land
use. This approach is identical to the one used for the discrete
model, but has the disadvantage of over- or underestimating
the presence of certain land-use types. The second comparison,
therefore, relates to the actual quantities (or ratios) of
land use, per cell (See the map comparison description in
Section 3, methodology).
4.2.2 Multinomial regression specification
The second calibration attempt uses the results from the
multinomial regression analysis presented in Section 4.1.2. A
comparison with the observed land-use quantities (Table 4.1)
shows that the continuous model performs reasonably well,
with a correspondence of 58% to 97%. This result is remarkable,
considering that the statistical analyses were performed
on the discrete data sets, rather than the continuous data set
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Calibration and validation of the Land Use Scanner allocation algorithms