Application of the least squares inversion method for vertical electrical sounding processing in the Colorado field (Santander) –a case study

Abstract

In the resistivity method, artificially generated electric currents are introduced into the ground and the resulting potential differences are measured at the surface, in subsurface layers of different physical characteristics, resistivity measurements and their respective anomalies provide information on the form and electrical properties of subsurface inhomogeneities. Resistivity is one of the most variable physical properties because it can be affected by small changes in climate or subfloor, for certain types of materials, water can modify their electrical properties; in saturated soil or water tables, the resistivity of a material tends to decrease. The distribution of lower resistivity ranges for different points are analyzed in order to estimate a surface distribution of these saturated levels. At Colorado Field was survey eight vertical electrical sounding; processing and interpretation of acquired data is done through the development of an investment using least squares to estimate the actual resistivity and depths that are best suited to modeling the theoretical curve