A diachronic study of Ourika watershed land in the High Atlas of Morocco

The Ourika watershed, located in the North-West of Moroccan High Atlas, has undergone several spatio-temporal changes and accelerated land use dynamics as a result interaction climatic, topographic anthropogenic factors. objective this study is to monitor evolution area over past 33 years. Landsat satellite imagery been chosen for cover mapping, providing sufficient detail identify characteristics while more or less complete coverage action. 5 Thematic Mapper images from 1987 8 Operational Land Imager 2019 were used, with spatial resolution 30m. treated classified using Support Vector Machine algorithm (SVM) implemented on QGIS Geographic Information System software. classification evaluation shows Kappa coefficient 85% 84% an overall accuracy 95% 94% respectively. Furthermore, results showed 10% decrease forest well significant increase pasture, arboriculture, bare buildings respective percentage 5.99%, 1.67%, 1.48% 1.37% accordingly.