Determining Subsurface Bedrock Depth Using Vertical Electrical Sounding: Principles, Applications, And Case Studies

Abstract

Accurate determination of bedrock depth is a critical parameter across numerous geoscience disciplines, including civil engineering, hydrogeology, and environmental studies. Traditional intrusive methods, such as drilling and digging, are often costly, time-consuming, and provide limited spatial coverage. This article provides a comprehensive assessment of Vertical Electrical Sounding (VES) as a non-invasive, cost-effective geophysical technique for evaluating subsurface bedrock depth. It elucidates the fundamental principles of VES, detailing its operational methodology, common electrode configurations (e.g., Schlumberger, Wenner), and the process of data acquisition and interpretation. The article highlights diverse applications of VES in geotechnical investigations, groundwater exploration, and environmental assessments, with a particular focus on its utility in bedrock mapping. Case studies from Nigeria illustrate the practical application of VES and the correlation of its results with borehole data. Furthermore, the discussion addresses the advantages and limitations of VES, comparing it with other geophysical methods and exploring future prospects, including the integration of artificial intelligence and machine learning for enhanced interpretation. This synthesis aims to underscore the indispensable role of VES in providing crucial subsurface information for sustainable development and infrastructure planning.