Characterization of the soil and rock hosting an aquifer with possible uses for drinking water and irrigation in SE Panama City using Geotechnical, Geophysical and Geochemical parameters

Abstract

The supply of water to populations is a basic need that has been threatened more frequently in recent years due to climate change, which renders seeking other sources of water essential. The hydrochemistry of the groundwater of the aquifer located in the UTP Tocumen was characterized by previous research to determine its possible use as a source of drinking water and irrigation water. The objective of this study is to characterize the soil and rock hosting the aquifer to acquire more information about them with a view to possibly exploit an alternative source of drinking water. To this end, a 10-m-depth survey was conducted to obtain soil and rock samples from the area, and to characterize geotechnical and geochemical parameters. 2D electrical resistivity tomography was used to create a lithological model of the aquifer and to correlate the data. Soil is residual of the technosol type, considered permeable with a transmissivity level that favors rainwater infiltration, followed by the soil–rock interface, where rock is weathered. It´s followed by a sedimentary rock corresponding to marly siltstones with a certain degree of tectonic fractures that allow water infiltration and its accumulation in the rocks, constituting the aquifer. The 2D electrical resistivity suggests two water accumulations: a superficial and a deep one. There was a good correlation between the aquifer water’s chemistry and the rock geochemistry.