Joint Geophysical Investigation of Uteh Gully Erosion and Landslides Using Electrical Resistivity Tomography and Multichannel Analysis of Surface Waves

Abstract

Joint investigation of gully erosion and landslides was carried out by employing Electrical Resistivity Tomography (ERT) and Multichannel Analysis of Surface Waves (MASW) methods of geophysical investigation. Data were acquired using PASI 16GL model resistivity meter and a 24-channel ABEM Terralock MATK-6 seismograph for ERT and MASW respectively along two traverses each. Data acquired for ERT and MASW were processed with Res2dinv and SeisImager2D refraction software developed by Geometric Earth Science Ltd respectively and a 2-D resistivity image and 2-D shear wave (Vs) and P-wave (Vp) velocities of the subsurface were generated. 2-D resistivity subsurface imaging reveals presence of topsoil, clay, sand and coarse sand. The shear wave velocity and elastic parameters reveals soil ranging from soft to medium-stiff clays/dry sand/wet sand and medium-stiff to stiff saturated clays/dry sand/wet sand. This shows the susceptibility of the area to gully erosion due to incompetent soil structures.