Soil Adjusted Vegetation Index (SAVI) produced from the 2005 Landsat Thematic Mapper(ETM) image. SAVI is a means of monitoring density and vigour of green vegetation growth using the spectral reflectivity of solar radiation. It is computed as follows:( (NIR-RED) / (NIR+RED+L))*(1+L), where NIR (Near Infra-Red) is the TM band 4 (0.76-0.9 micrometers), RED is band 3 (0.78-0.82 micrometers), and L is the correction factor whose values range from 0 (high vegetation cover) to 1 (low vegetation). L=0.5 was used. The index has been designed to correct for high soil reflectance in arid regions.