Mapping lineaments using Landsat 8 OLI and SRTM in the Boumalne-Imiter regions of the southern Central High Atlas. Morocco

Abstract This work presents the results of the automatic extraction of lineaments in the region of Boumalne-Imiter, which is located on the southern front of the Central High Atlas. These lineaments are extracted by remote sensing and Geographic Information System (GIS) approaches. These approaches are based on the first principal component (PC1) and the panchromatic band (B8), which are derived from a Landsat 8 OLI satellite image. These data underwent a 3*3 matrix directional filtering, with the addition of a shading effect on the digital terrain module STRM. These treatments allowed us to establish a synthetic lineament map of the study area. It consists of 1251 lineaments whose length varies between 407.75 m and 8.7 km and whose distribution is dominated by the class with lengths varying between 400 m and 1422 m. The direction of the lineaments is dominated by three families respectively, NE-SW, ENE-WSW and E-W. The density map shows a high intensity in the Saghro Massif (Eastern Anti-Atlas) and in the area that extends between the village of Ait Ibrirne and Arg-n-Sidi Ali Oubourk. Validation of these results is based on comparison of the synthetic map with the geological maps, the high-resolution satellite image (ESRI), in addition to two factors for validation. The first of these is the lithological factor, which shows us that the lineaments are often focused in the competent rocks, as is the case of the magmatic rocks of Saghro Massif in the south-east and also the limestones of the Jurassic and Paleocene-Eocene in the north. However, the second factor is the superimposition of the lineaments on the map of the slopes. This reflects that the concentration of lineaments is quite marked in places where the slopes are steep by steep, while the abrupt change of slopes is probably generated by the play of faults. The correlation of these results with previous work allows us to say that the area is made up of two domains. The first corresponds to the poly-orogenic Anti-Atlas with a very important tectonic heritage. The second is attached to the Atlasic domain, influenced by the southern Atlasic accident which is expressed by overlaps that occurred during the Atlasic uplift. The method of automatic extraction of structural lineaments is considered a useful reference technique due to its validity and accuracy in the selection of structural lineaments, and is considered as having an additional value in this type of study.