Cartographie et suivi de la densité des arbres de l'arganeraie (sud-ouest du Maroc) à partir d'images de télédétection à haute résolution spatiale

The study is focused on surveying and monitoring tree cover in the argan tree sparse forest of South-West Morocco. Remote sensing data are one IKONOS image from 2003 and one GeoEye image from 2011 (obtained through Google Earth); the latter image has been registered with the 1m resolution IKONOS image used as reference. An object-oriented classification approach has been used to identify tree crowns on both images. However the multi-temporal comparison of results of the two classifications appears not reliable. An alternative solution is proposed through the interactive analysis of the scattergram of 2 channels, one from IKONOS (panchromatic) and one of GeoEye image (sum of 3 bands). In the studied area, tree cover is very low (about 8%) and there are no drastic changes in tree density from 2003 to 2011, except in restricted disturbed areas.