Mapping and analysis of structural lineaments using SRTM radar data and Landsat-8 OLI image: an example from the Telouet-Tighza area, Marrakech High Atlas, Morocco

This study provides the first evaluation of the potential of both Landsat-8 Operational Land Imager (OLI) sensor images and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) data, for automated lineament extraction in the south side of Marrakech High Atlas (MHA), (Telouet-Tighza area). After image corrections, enhancement methods such as Principal Component Analysis (PCA), Band Composite (BC) and Directional Filter (DF) were adopted in order to create new images that provide high visibility of linear structures. The new Landsat BC image used in this study was selected based on the calculation of the optimum index factor (OIF) and Correlation Index. In addition to the Landsat image, the SRTM DEM is used to detect structural lineaments in the area, by generating shaded relief images. Multi-source data, such as Band Ratio (BR) image, geological maps and fieldwork, were used to eliminate the non-geological lineaments extracted. The results indicate that automated method was applied successfully for lineament mapping in this area, by detailing the main tectonic faults. Moreover, new lineaments are identified and are validated by field works. Structural lineaments extracted show compatibility in their direction, length, distribution and density with the tectonic evolution of the study area. A total of 2945 lineaments are extracted with major ENE-WSW, and predominant E-W directions. The new structural map shows more structural information compared with the geological map of this area, and exemplifies the performance of Landsat-8 OLI bands and SRTM data in this kind of study.