Coefficient of variation (CoV) can be used to compare the amount of variation in different sets of sample data. NDVI CoV
images were generated by computing for each pixel the standard deviation of the set of individual NDVI values and dividing
this by the mean of these values. It is recommended that the maps should be considered in the field investigation - in particular
the land use change during the study period (1981- 2003).
A positive change in the value of a pixel-level CoV over time relates to increased dispersion of values, not increasing
NDVI; similarly, a negative CoV dispersion – which is the case over nearly the whole country - means decreasing dispersion
of NDVI around mean values, not decreasing NDVI.