4.1. Interpretation of NDVI maps
The results obtained support our theory of the decline of perennial vegetation in the study area. The regression of the recovery is marked by the reduction of chlorophyll levels. For this purpose, the minimum and maximum NDVI values ​​were disturbed during the observation periods (Figure 4). The rate of the cover vegetation in 1987 was estimated at 49.0%, this value decreased to 4% in 2018 compared to the total area of the municipality. The production of forest formation maps between 1987 and 2018 after the performance estimate of our classifications mentioned in Table II.