Extraction of Lineaments Using Landsat Image and Digital Elevation Model: A Case Study of Zagros Orogenic Belt, West Iran

The extraction of structural lineaments was conducted on a portion of the Zagros orogenic belt in western Iran, using filters applied to Landsat satellite imagery (ETM) and a digital elevation model (DEM). The study area was divided into internal (Sanandaj-Sirjan) and external (Zagros) subzones by the Main Zagros Thrust. To extract lineaments, Edge Detector, Spectral Rationing, Principal Component Analysis (PCA) filters, and color combinations were applied to the ETM satellite imagery, while a directional filter (Sobel) was applied to the DEM for enhanced visual interpretation. The analysis identified 350 fault lineaments with a total length of 3689 km. The majority of these lineaments were shorter in length, with 188 lines measuring over 5 km, 110 lines between 5 and 10 km, 39 lines between 10 and 20 km, and 10 lines between 20 and 30 km. Only three lineaments exceeded 30 km in length. Statistical analysis of the lineaments, presented in Rose diagrams, revealed a predominance of NW and NE trends, with less frequent WNW, NNE, and E-W trends. The most dominant trend observed was NW. These findings suggest that the extracted lineaments are largely consistent with the faults in some inner subzones identified in previous studies of adjacent areas. However, differences in lineament orientations and densities, when considering subzones, were attributed to the likely reactivation of basement faults.