ANALYSIS OF VEGETATION THROUGH SUBTRACTION OF NDVI IMAGE IN SUB-BASIN OF THE HORIZONTE STREAM, ALEGRE, ES

This study aimed to assess changes in vegetation cover in the sub-basin of the stream Horizonte, Alegre - ES that occurred in past decades, through the subtraction of pairs of images NDVIs. Original images were used sensor Thematic Mapper (TM) aboard Landsat 5, dated 01/06/1987 and 31/05/2010 passages. The results show the efficiency of the technique of subtraction NDVIs to portray the changes in vegetation cover in the sub-basin. The generated maps showed decreased levels of NDVIs between the two dates analyzed, it was noted that 70.18% of the sub-basin are within the class of non-change, suggesting a good state of repair. However, when considering the class of deforestation was found that 49.32% of this occurred in the area of head, region of extreme importance for the supply of groundwater, thus signaling the need for a specific policy on environmental education to prevent future problems.