Secondly, the urban built-up category for each year was further
classified into three different land use classes (i.e., residential,
commercial/industrial, and other urban) by using the ARC's LandPro
GIS databases. Specifically, we extracted the polygons of each
urban land use class and converted them into binary layers that
were then overlaid with the classified map to produce the detailed
land use/cover maps. Because the ARC's LandPro data were not
available for the year of 2000, the LandPro 2001 layer was used as a
substitute and was modified with reference to the Landsat TM 2000
images. In addition, the spatial extents of LandPro data for both
years did not cover the entire 29-county Atlanta region, we
therefore manually digitized the outside urban area based on visual
image interpretation as described by Campbell (2002). Note that
the un-covered region for each year only contains a relative smaller
percent of the total urban area. The GIS overlay procedure used the
classified output as the base map, while only the urban pixels
within the classified map were further reclassified into the three
corresponding land use categories. The primary reasons for this
procedure include: (1) the mapping units of the LandPro data for
both years were relatively coarse compared to the satellite imagery's
pixel resolution; and (2) the mapping units of the two different
years' LandPro datasets were different which may be problematic
in land change analysis. We therefore relied on the classified map
from remotely sensed data to provide both spatial accuracy and
temporal consistency in the change analysis.
Secondly, the urban built-up category for each year was further
classified into three different land use classes (i.e., residential,
commercial/industrial, and other urban) by using the ARC's LandPro
GIS databases. Specifically, we extracted the polygons of each
urban land use class and converted them into binary layers that
were then overlaid with the classified map to produce the detailed
land use/cover maps. Because the ARC's LandPro data were not
available for the year of 2000, the LandPro 2001 layer was used as a
substitute and was modified with reference to the Landsat TM 2000
images. In addition, the spatial extents of LandPro data for both
years did not cover the entire 29-county Atlanta region, we
therefore manually digitized the outside urban area based on visual
image interpretation as described by Campbell (2002). Note that
the un-covered region for each year only contains a relative smaller
percent of the total urban area. The GIS overlay procedure used the
classified output as the base map, while only the urban pixels
within the classified map were further reclassified into the three
corresponding land use categories. The primary reasons for this
procedure include: (1) the mapping units of the LandPro data for
both years were relatively coarse compared to the satellite imagery's
pixel resolution; and (2) the mapping units of the two different
years' LandPro datasets were different which may be problematic
in land change analysis. We therefore relied on the classified map
from remotely sensed data to provide both spatial accuracy and
temporal consistency in the change analysis.
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