Application of the Natural Potential Method for the exploration of groundwater in the El Pedregal Volcano area, Tegucigalpa, Honduras.

Abstract

The demand for water resources to supply water to populations facing scarcity has forced the implementation of a number of exploration tools based on scientific, semi-empirical and empirical principles. The use of each of these tools is mainly conditioned by the costs of the equipment, the execution of these studies and the surface dimensions of the areas to be explored.
In the area of El Pedregal Volcano, an area of urban expansion north of Tegucigalpa, where the accelerated growth of human settlements that do not have drinking water services, has encouraged government authorities and international organizations to conduct studies to identify sites with potential for drilling wells.
A total of 6 profiles of natural potential with a length of 30 m and a depth of 300 m were executed. The objective of the profiles was to identify the fault and fracture lineaments, with the intention of defining if this contributes water to the subsoil.
The results showed the presence of low values of electrical resistivity, characterizing a confined aquifer, located 30 m below a layer of basalts little altered and with low fracturing, which acts as a seal layer due to its low permeability. This zone is located southeast of Laguna El Pedregal and no relationship was detected between the lagoon and the high conductivity layer.
The application of the low-cost Natural Potential method known in the market as “Water Finder”, which is considered a semi-empirical equipment and easy to use by the operator, generated positive results in the areas where this research was developed.
The results obtained have made it possible to locate a semi-confined aquifer that can be used as a source of groundwater supply for the neighborhoods around Laguna de El Pedregal.