Rock discontinuities mapping with computer-based lineament extraction from satellite imagery

Abstract

This study presents an approach for automatic lineaments analysis by using high-resolution digital images for mapping and delineating rock discontinuities. As a case study, we combine Landsat 8 images with 15 m resolution and shuttle radar topographic mission (SRTM) of a discovered gold mine in Nuba Mountains, Sudan. The satellite image contains band 7, band 4, and band 1 in red, blue, and green. In addition, band 5 is assigned to obtain the average of the three bands. The automatic extraction of lineaments approach was initially carried out with PCI Geomatica software, and then an accuracy assessment is performed to determine the most accurate parameters of extracted features. On the excellent reference of the output, the extracted lineaments are transferred to the Arc map software, and the coordinates of lines have been fixed. Finally, the attribute table of lineaments was imported to Rockware software to draw the rose diagram. Moreover, a manual lineament extraction process is carried out. For comparing automatic lineament extraction and manual lineament extraction, total length and number of lineaments and directional analyses are done by constructing the rose diagrams. Besides these two processes, field investigation in the study area is also applied to verify digitally extracted lineaments that the features represent true discontinuities. The final parameters of automatically extracted lineaments are determined. The produced lineament map in this study is proved to be very efficient in the discontinuities mapping for mining applications in terms of cost and time effectiveness.