3.5.1 Images Data Preparation, Classification and Analysis
The first step to this research is preparation of Landsat 7ETM+ pathrow:
12265, 2001 using ER Mapper 6.4 software to obtain Settlement Area, surely
after correcting spatial distortion in an image geometric correction and removing noise and image intensity variations due to antenna radiation pattern dan ground
scattering elements before. In this research topographic map from BAKOSURTANAL data used in geometric correction as the GCP ground control
point information to rectify the errors. After all images corrected, the next procedures is classifying image by unsupervised classification to obtain the
classified imageries. Furthermore, from the classified imageries, querying performs to obtain settlement and openland area that have dimensional bigger
than 10 hectares. Finally, the desirable Settlement Area obtained after
performing overlay analysis union base on the image by means ArcGIS software.
Meanwhile, by means of Landsat 7ETM+ pathrow 12265, year 2001,
another procedures to obtain Mineralization Zone can generated by extracting
iron-oxide and clay mineral in an image by performing PCA principal component analysis, filtering and convertion in ER Mapper software.
Another images data preparation is to generate Slope Stability Risk Zone
from SRTM data. As does Landsat imagery, SRTM also use topographic map to make its corrected by geometric correction procedures in ER Mapper. Afterwards,
DEM obtained by generating contour in ArcGIS, where Slope Stability Risk Zone
obtained from weighting the slope generation based on characteristics of the slope categories for land development Table 3.1..
33
Generally too steep for real real estate development. Best resticted to wildlife, forestry, and limited grazing.
Over 50 percent over 27
High-rise apartment clusters and large-lot residences appropriate. Low density required. Suitable for
low-intensity recreation and summer resorts. Forest and grazing lands.
30 to 50 percent 17 to 27
Too steep for most cultivation. Erosion problems. Slopes up to 20 percent suitable for crops such as
artichoke and brussel sprouts. Also suitable for limited light industry, detached houses, high-rise apartments,
institutional complexes and intensive recreational facilities.
15 to 30 percent 9 to 17
Moderately sloping. Too steep for airports or most heavy industry. I rrigation restricted but suitable for
dry farming. Good drainage. Good setting for residential development.
5 to 15 percent 3 to 9
Almost level. Suitable for urban and agricultural development. Part susceptible to flooding and part
with poor drainage. 0 - 5 percent
0 to 3
Characteristics and Suitability Slope Category
Table 3.1. Characteristics of the slope categories for land development Howard Remson 1978
3.5.2 Vector Data Preparation, Classification and Analysis