Lineaments mapping and digital analysis using remote sensing and geographic information system (GIS) in Erusu-Akoko area of Akoko North-West, Southwest Nigeria

Lineament analysis constitutes an interesting approach in geological studies, and it is considered as a very important structural and geological indicator used to determine regional, local tectonic trends and fracture zones in the rocks. Lineament extraction from satellite data has been the most widely used application in geology with several techniques. This study was carried out to illustrate the application and importance of remote sensing and geographic information system (GIS) techniques for lineaments mapping and digital analysis. The study demonstrates the use of NigeriaSat-X imagery for mapping and analysis of lineaments in the Basement Complex region of Akoko North-West area of Ondo State, Nigeria. Digital image processing techniques involving linear/edge enhancements, pan-sharpening and principal component analysis (PCA) were applied on the image to enhance the edges of the linear features using ENVI 5.3. The enhanced image was visually interpreted through GIS operations for lineaments extraction through on-screen digitizing using ArcGIS 10.5. These extracted lineaments were statistically analyzed to determine their lengths and densities. The results obtained were used to generate a lineament density map, lineaments statistics, and rose diagram. The lineaments have minimum and maximum lengths of 619.20 m and 6,099.13 m, respectively, with a total length of 349,358.56 m and an average lengths of 1,647.92 m. The lineament/fracture analyses indicated that the area has several long and short fractures whose structural trends are mainly in the north-west and south-east directions. These lineaments are relatively high in areas around the central and south-western parts of the study area, and relatively low in the other areas. The results show that the integration of remote sensing and GIS, as well as manual lineaments extraction techniques carried out on NigeriaSat-X satellite imagery, provides a powerful tool in lineaments mapping and digital analysis