Vegetation response of Chennai City using Normalized difference vegetation index (NDVI) from Landsat images

Remote sensing can present an efficient and reliable means of collecting the information and with the multispectral sensors can provide information of about the health of the vegetation. The spectral reflectance of an area will vary with respect to changes in the crop type, health and growth. The study deals to calculate the NDVI (Normalized difference vegetation index) for the Chennai City using remote sensing technique by using open source Quantum GIS software. For this purpose Landsat ETM+ images of the year 1991 and 2006 was obtained for the study area. The NDVI values for the year 1991 vary from-0.31 to +0.42 and during 2006 it varies from-0.36 to +0.48