Normalized Difference Vegetation Index Maps of Pune 1991, 2000, 2011
Vegetation indices maps are useful indicators of vegetation cover and can help in distinguishing various land cover classes. We used the Normalized Difference Vegetation Index (referred to as NDVI from here on) to document and evaluate the changes in the vegetation cover in our study region and also as a means of identifying useful land cover classes for this study. The spectral bands used for this purpose were the red and near infrared bands as active terrestrial vegetation strongly absorbs red light and strongly reflects near infra-red energy. The NDVI maps were created using the following formula (Tucker 1979):
NDVI = (Near Infrared Band – Red Band) / (Near Infrared Band + Red Band)
where for all the datasets,
NIR band = Band 40 reflectance file
Red band = Band 30 reflectance file
The NDVI generated maps can help in identifying different land use and land cover features such as water bodies (NDVI values typically negative and 0), areas of no vegetation- mostly bare soil (0 to 0.2), light to moderate vegetation (NDVI values 0.2 to 0.4), and dense vegetation (NDVI values 0.5 to 1.0).
NDVI 1991
NDVI 2000
NDVI 2011
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