Landslide is the major geohazard in the Ethiopian highlands. We used InSAR and Arc-GIS techniques to map landslide susceptibility. SAR images generated from sentinel 1A are utilized for landslide displacement investigation using InSAR method. GIS analyses result showed that it is a powerful technique to landslide zoning in to low, moderate, high and very high, susceptibility whereas wrapped Interferogram shows a displacement of -12 to 12 mm/yr. Thus, very high and high classes of landslide zoning overlapped on the highest displacement regions. Results were validated with GPS data using R-index method. Accordingly, 79.45% of sample point’s fall on the displacement map (Interferogram) and the same percent of those points overlapped to very high and high landslide zones. Landslide triggered deformation and landslide susceptibility mapping can be well studied using InSAR, which has a capability to give constant coverage and accuracies better than that of classical studies. To interpret and integrate different InSAR results GIS is utilized as a value-adding technique throughout the InSAR process. This means InSAR and GIS method can be utilized for landslide vulnerability mapping but for more accuracy and quantification of landslide displacement.
Electrical resistivity method has been identified to be one of the most suitable geophysical method/technique for groundwater or borehole development. Therefore, this research work was carried out using Vertical Electrical Sounding (VES) to recommend a suitable location for borehole drilling in Unity secondary school compound, Owo LGA, Ondo state with the specific objectives of delineating lithological unit that contributes the overburden using resistivity parameters, to identify the aquifer units and delineate the thickness and lateral existent. The Schlumberger electrode configuration was adopted for the field investigation. Two Vertical Electrical sounding stations were occupied during the survey in the area. A and H curve types were obtained from the field data. Quantitative and qualitative interpretation was carried out that reveals Topsoil, Lateritic hardpan/clay, Fresh basement and fractured basement that underlie the area.
Mineral investigations and knowledge of their chemical composition are the fundamental facts in determining the deposit's economic potential. In the study field, different rock and mineral samples were collected including limestone (LS6, LS7, and LS8) and granitoids samples (S1, S2, S3, and S4). The detailed investigations reveal that the limestone samples are dominated by calcite associated with accessory minerals, the granitoid samples show high levels of silica minerals and some ultra-high metamorphism minerals of granulite facies. Based on [20] classifications of granitoid, the samples fall in the ferroan granitoid [Fe2O3 (t)/ (Fe2O3 (t) +MgO]. Modified Alkali-Lime Index (MALI) plotting [Na2O+K2O-CaO] against SiO2.
2D Electric resistivity imaging and Induced polarization (IP) techniques were used to evaluate Iron Ore deposit at Potiskum area of Yobe State, Northeastern Nigeria. The area lies between latitudes 110 40' 00'' and 110 50' 00'' N, and longitude 110 00' 00'' and 110 10' 00'' E. The survey was targeted at determining resistivity and chargeability values that are associated with the iron ore deposit. The dipole-dipole array was used for 2D resistivity and induced polarization imaging. Data processing and interpretation were done using RES2DINV software. This research had characterized the study area into two portions: the alluvium deposit that is highly enriched of iron ore and alluvium deposit with disseminated iron ore. The portion of the iron rich alluvium, characterized by low resistivity and chargeability of 32 Ωm to 734 Ωm and 0.403 msec to 3.400 msec are inferred as alluvium that is highly enrich with iron ore, while the portion that are respectively characterized by resistivity and chargeability values of 734 Ωm to 1418 Ωm and 1.90 msec to 6.40 msec are inferred as alluvium with disseminated iron ore. It can be concluded that the occurrence of iron ore deposit is probably more at northeast part of the survey area. The iron ore deposit strikes in the Northeast-Southwest direction.
