While governmental land-use maps have their flaws, some
relevant information could be extracted from them in order to
improve the remote-sensing based classification. Created in 2004,
the CBS map has been based on data from 2002. Although delineation
of built-up terrain (housing and agricultural buildings) in the
Bedouin diaspora of the Negev was added in 2007, this map is not
updated for recent changes in land-use. While the CBS map is very
detailed for urban and built-up land-uses and moderately detailed
for agricultural land-uses, it does not account for areas used for
pasture. These rangelands are categorized under “other open
grounds” together with everything that does not fit into one of the
other land-use classes of the CBS map. The Survey of Israel map is
much more expensive and thus, only parts were available for use.
Moreover, those parts were updated for 2004. Morphological cover
features and orchards are mapped to a great detail but areas used
for pasture are not defined. Also, some, but not all urban land-uses
are defined. Most built-up areas are included in the “area without
known characteristics” class together with other land-cover classes
that do not fit in any class. Since both maps are relatively up-to-date
and contain some useful information for land-use classification,
they were combined to enhance the remote-sensing based classification
efforts.
Land-use polygon layers were clipped according to the research
area boundaries and converted to ERDAS raster format using
ARCGIS. The data was resampled to 30 m resolution to match the
Landsat TM data. Each of the land-use and land-cover classes of the
original maps was recoded into the most fitting of the six land-use
classes (Fig. 3). No classes were recoded into the “Water” and
“Barren land” classes.
A Decision Support System (DSS) was designed (Fig. 4) based on
a set of logical land-use trends, and the “convergence of evidence”
approach (Sader et al.,1995) whereby a pixel’s value is updated only
if an indicator exists in all data layers. It was decided not to update
water and barren land pixels since the land-use maps do not
account for them. To clear up some of the “salt & pepper” noise