Remote Sensing Vegetation Dynamics Analytical Methods: A Review of Vegetation Indices Techniques

Scientists have made great eff orts in developing techniques to assess and monitor the rate of change in vegetation on global, regional and local scales. Vegetation indices are remote sensing measurements used to quantify vegetation cover, vigor or biomass for each pixel in an image. Besides the fact that no single method can be applied to all cases and regions, there are some factors that determine the remote sensing methods to be used in environmental change studies. Such factors include the spatial, temporal, spectral and radiometric resolutions of satellite image and environmental factors. The major question usually comes to mind of environmental researchers in any remote sensing research project is: What remote sensing method should be used to solve the research problem? Therefore, this paper evaluates methods used in the literature to assess, monitor and model environmental change, considering factors that determine the selection of those methods. The review shows over forty vegetation indices, out of which only three (Ratio Vegetation Index, Transformed Vegetation Index and Normalized Diff erence Vegetation Index) are commonly applied to vegetation assessment. The study show that out of all the vegetation indices, NDVI is the most widely applied to monitor vegetation change on regional and local scales.