Long-term monitoring of moisture changes in sedimentary soil of the Panama through non-invasive time-lapse ERT methodology

The aim of this work was study the effects of climate and vegetation on the moisture content present in soils that support a complex vegetation system which comprises a pasture and micro-forest area, at the Center for Innovation and Technology Transfer of the Technological University of Panama located in Aguadulce, Cocle. For such purposes, a geophysical monitoring was carried out through four electrical resistivity tomographies on a 23.5 m long profile developed in the rainy season from July 9 to October 29, 2019 with time lapses of 38, 34 and 39 days between them. The datasets were inverted using a time-lapse ERT code based on the Boundless Electrical Resistivity Tomography (BERT). With the results obtained in this work (electric resistivity tomographies), was possible to delimit the electrical anomalies related to the physical characteristics of the subsoil in both: the pasture and the micro-forest area. Geophysical monitoring and volumetric moisture content calculated via Archie's law, allowed quantifying the dynamics of moisture content in both areas with significant percentage differences between -50% and 100% over the micro-forest area. This leads us to evaluate the levels of moisture absorption in both areas and consider the problem of land use and the impact it has on the groundwater recharge processes in this important region of the country.