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data files.
The Combomap Anal program takes a secondary classification data file as
input. It prints the data file in map format and prints a table of
class pixel counts and hectareage. This program also maps separately a
selected class by request.
Each secondary data file of Old Machar Parish created by the Boundary
Determ program was processed through the Combomap Anal program to
generate maps and class area statistics (Table 1). Maps of residential
lands were also printed by request.
The Map Change Detec program compares secondary classification data
files of the same location for two different years and determines the
areas of change for a selected class. In the process four maps are
printed with accompanying pixel and hectareage counts: (1) selected
class present in the earlier year, (ii) selected class present in the
later year, (iii) selected class added between the two years, and (iv)
selected class lost between the two years. The map of pixels lost is
also stored as a data set.
The Old Machar secondary classification data files were processed by the
Map Change Detec program to identify and quantify the areas of change in
cropland (class A) between 1966 and 1981. Figure 1 shows the map of
lost cropland generated by this program.
The New Land Cover program compares a data file of lost pixels created
by the Map Change Detec program with the classification map of the later
date to determine the land cover which has replaced the lost class. A
map of the new land cover and a table of pixel counts and hectareage of
the new classes are printed.
Old Machar cropland lost maps were processed through the New Land Cover
program to produce the resultant new land cover maps and tables (Table
3).
The Land Capability program compares a map of lost agricultural pixels
with a land capability map to determine the land capability lost. The
program prints a map of land capability lost and a table of pixel and
hectareage counts of the types of land capability lost.
For the Old Machar study, a 4 NGS area—which contained over half of the
cropland lost within the parish—was selected to analyze land capability
lost. Land capability data files were based on land capability data
gathered and classified by the Department of Agriculture and Fisheries
for Scotland according to a seven-grade scheme.
RESULTS AND DISCUSSION
The data from remote sensing reveals that 321.2 hectares or 16 percent
of the land classed as cropland (A) in 1966 had changed to another land
cover or use by 1981. Most of the change was from cropland to either
residential (R) or commercial/industrial (C) (Figure 1 and Table 3).
Some of the cropland adjacent to urban developments has changed to
permanent pasture (Z). This is probably an intermediate step before
further urban encroachment brings about a residential or industrial use.
Resultant agricultural data is compared with the farm census data of the
Department of Agriculture and Fisheries for Scotland in Table 4.