Fracture Network Mapping Using Landsat 8 OLI Data and Linkage with the Karst System: a Case Study of the Moroccan Central Middle Atlas

Abstract

The central Middle Atlas, with its Mesozoic carbonate cover has undergone several tectonic and karstic phases and is characterized by a hydrological system with a complex karstification. The spatial and structural analysis of fractures and karst networks in a complex hydrological system may allow for the accurate identification of zones that favor the infiltration and recharge of overexploited groundwater. The present study aims to characterize the fracture network in the Moroccan Central Middle Atlas using multispectral satellite images from a Landsat 8 Operational Land Imager sensor for automatic lineament extraction. Our methodology focuses on a linkage between the direction, length, and density of lineaments with the characteristics of surface karst as well as the tectonic system of the study area. The remote sensing techniques used have shown their effectiveness in lineament mapping, such as principal component analysis coupled with directional filters. The resultant fracture network is oriented NE–SW, N–S, and NW–SE with a predominance of the NE–SW direction, showing a good correlation between the distribution and orientation of the lineaments and the alignments and elongations of the karstic shapes. In addition, this paper explains the tectonic origin of surface karstic shapes and the influence of tectonic and karstification on the distribution and function of the hydrological system of the Central Middle Atlas.