3.1. Database preparation
Landsat Thematic Mapper at a resolution of 30 m of 1990 and
2010 were used for land use/cover classification. The satellite
data covering study area were obtained from global land cover
facility (GLCF) (http://glcfapp.glcf.umd.edu:8080/esdi/) and
earth explorer site (http://earthexplorer.usgs.gov/). These data
sets were imported in ERDAS Imagine version 9.3 (Leica
Geosystems, Atlanta, U.S.A.), satellite image processing software
to create a false colour composite (FCC). The layer stack
option in image interpreter tool box was used to generate
FCCs for the study areas. The sub-setting of satellite images
were performed for extracting study area from both images
by taking geo-referenced out line boundary of Hawalbagh
block map as AOI (Area of Interest). For better classification
results some indices such as normalized difference vegetation
index (NDVI), normalized difference water index (NDWI)
and normalized difference builtup index (NDBI) were also
created to classify the Landsat images.