ANALYSIS OF LAND USE AND LAND COVER CHANGES IN THE VALLEY OF THE VAROSA (PORTUGAL) BY LANDSAT-TM IMAGES AND ITS INFLUENCE ON SOIL CONSERVATION

The landscape of the Varosa Valley underwent major changes in recent years due to several factors, among which stands out the land use change. The evaluation of soil conservation and quantification of landscape changes in this valley over the past three decades are the objectives of this study. The results show the variation of the area of clusters determined by unsupervised classification of land cover from Landsat 5TM images from 1984 and 2011, demonstrating the expansion of these forest and urbanized areas. We compared the normalized vegetation index (NDVI) of these two years with the previous results to perceive changes in the use and occupation of land, verifying the increase of vegetation cover on abandoned agricultural areas and the reduction of vegetation cover due to forest fires, a factor which affects the amount of soil lost by erosion processes and landscape changes.