Vegetation Cover Monitoring and the Topographic Influence Sierra Alhamilla SE Spain

摘要

The objectives of the study were to monitor the vegetation changes in a period of nine years (1984, 1989 and 1992) using Landsat TM imagery, to use the NDVI to identify healthy and non-healthy vegetation and to analize the influence of altitude and aspect in the NDVI values. The area of Study was Sierra Alhamilla, SE Spain. The discrimination of vegetation types was done by thresholding the NDVI images for the three years and a DEM was used to obtain the altitude and aspect images. The results showed firstly, that the increasing of the healthy and non-healthy vegetated areas, from 1984 to 1992, are associated to the increase of Rainfall in a linear fashion. Secondly, there is also a linear influence of the altitude on the NDVI independent from the actual rainfall. This linear relationship has differenet slope from North to South and a bigger altitude increment is needed in the South to get the same NDVI increment. Finally, the influence of aspect is mainly between North and South with minimum variation between East and West.