1D Joint Inversion of DC and TEM Data for Hydrogeological Applications - Preliminary Results

Electrical (DC) and transient electromagnetic (TEM) soundings have been used in great number of hydrological,environmental, and mining exploration studies. The data interpretation usually is done individually by 1D models resulting in ambiguous results. This fact can be explained by how the two different methodologies observe the medium below the surface. The vertical electrical sounding (VES) is good at marking very resistive structures, while the transient electromagnetic sounding (TEM) is very sensitive to map conductive structures. Another difference is that VES is better to detects shallow structures, while TEM soundings can reach deeper layers. In this way, a Matlab program for joint inversion of VES and TEM soundings was developed aiming explore the best of the both methods. Initially, the algorithm was tested with synthetic data and after was used real data from Paraná Sedimentary Basin in Bebedouro region, São Paulo State, Brazil. The geoelectrical model obtained from joint inversion of VES and TEM data are more similar to the real geological condition and ambiguities were minimized. The results with synthetic and real data shows that joint inversion of VES/TEM is better for recovering the simulated models and shows a great potential in geological studies, particularly in hydrogeological studies.