Principal Component Analysis of ASTER imagery for Geological Mapping in the Central Jebilet Massif-Morocco تحليل المكونات الرئيسية لصور ASTER لرسم الخرائط الجيولوجية في الكتلة جبيلات الوسطى بالمغرب

Remote sensing is widely used in geological mapping, particularly in semi-arid environments where sparse vegetation enhances the spectral expression of surface materials. ASTER multispectral imagery, combined with Principal Component Analysis (PCA), has frequently been applied to enhance lithological contrasts; however, its contribution to geological interpretation is often presented descriptively. This study evaluates the contribution and limitations of PCA applied to ASTER VNIR–SWIR data for geological mapping in the Central Jebilet Massif, located in the Rehamna region north of Marrakech (Morocco). PCA was used to reduce spectral redundancy and enhance spatial variability, with emphasis on the first principal components that concentrate most of the spectral information. The results show that PCA effectively enhances major lithological contrasts and reveals spatial patterns related to deformation and magmatic intrusions, facilitating comparison with the existing geological map. Nevertheless, spectral ambiguities persist in areas affected by surface weathering and lithological mixing, highlighting the interpretative limits of PCA when used alone. Overall, PCA constitutes a valuable support tool for geological interpretation in semi-arid terrains, provided that results are carefully validated by geological knowledge. Journal of Legal, Spatial, and Development Studies, Vol. 1 No 5 (2026): عدد خاص حول أعمال الندوة الدولية: الجغرافيا الطبيعية والتحولات الاجتماعية والمجالية