Geophysical characterization of near-surface formations in the La Villa River catchment (Los Santos, Panama)

The central Pacific Region (Panama) is known to suffer from water scarcity during periods of extended drought. The groundwater/surface water interactions and dynamics, provided by conceptual or numerical models are crucial for water resource management. At the regional scale, such models generally lack of structural information concerning the internal variability of the near surface formations. The spatialization of the direct observations from sparse boreholes can only achieved by geophysical investigations. The aim of this work is to characterize, in the La Villa groundwater basin, the near surface aquifer located in the lateritic horizon using electrical resistivity imaging (ERI), vertical electrical soundings (VES) and time domain electromagnetic soundings (TDEM). This case study illustrates the relevance of the use coupled ERI, TDEM and VES to describe the near surface variability due to the leaching of the lateritic horizon as well as the level of the water table.