ABSTRACT
By using the instruments and methods of remote sensing, it is possible to detect forest damage caused by pests or calamities, while reducing time demands and achieving nationwide assessment of the area. This paper deals with the determination of the extent of deforestation in the Rožňava district (Slovakia) on the principle of calculating the normalized difference vegetation index NDVI from multispectral images of Landsat 5 and Landsat 7 satellites. The data sets were prepared in 5-year epochs using the JavaScript programming language and satellite bands B3, B4, B5, and B7 so that the cloudiness is eliminated from images while displaying the forest cover during the vegetation period. The NDVI calculation was performed in the ESA SNAP software. The resulting data classification was subsequently realized by calculating the percentage decrease in QGIS 2.18 software.
