Application of Geophysical Methods for the Delimitation of Potential Groundwater Zones in Rural Areas

The search for groundwater has become a necessity because of the effects of climate change and the resulting water shortages.In rural areas, such as the "Pampa del Guasmo" (Yaguachi-Ecuador), freshwater is supplied by building shallow artisanal wells.Applying this practice sets challenges to complement the technical-scientific knowledge of aquifers, opening up the need to apply geophysical-hydrogeological techniques to characterize the terrain.The study aimed to identify areas with water saturation at greater depths using geoelectrical methods to determine suitable drilling sites that meet the community's water needs.The methodology includes: i) analysis of cartographic base information, ii) execution of electrical resistivity tomography (ERT) complemented with Multichannel Analysis of Surface Wave (MASW) + Microtremor Array Measurements (MAM) surface wave tests and rotary drilling, iii) preparation of geoelectrical profiles, correlation of geophysical-geoelectric and lithological information for the determination of potential groundwater zones.The results showed that the third layer with resistivities of 8.3-9.6 .m in profile ERT-L1 and 10-15 .m in profile ERT-L2 represent a semi-confined aquifer consisting of clayey-silty sand with the presence of gravel, located from 19 and 40 m depth, respectively.The application of geophysics is the key to identifying the potential for groundwater use, as corroborated by the drilling performed.Owing to the growing population in these sectors and the increased demand associated with lowering levels in excavated wells, the applied geophysics process verifies the need for deeper wells that must be managed concerning their use, environmental implications, and sustainability.