Author(s)

JAIRO DUENAS-TOVAR, FERNANDO MORANTE-CARBALLO, EMILY SÁNCHEZ-ZAMBRANO, MIRKA ARCENTALES-ROSADO, GLADYS QUIROLA, PAÚL CARRIÓN-MERO

Abstract

The development of sustainable and efficient strategies for identifying and locating groundwater sources is key in rural areas with water scarcity and limited geological information. In the canton of Paján, in the province of Manabí, Ecuador, the climate is variable with a minimum monthly rainfall of up to 2 mm, which indicates low water availability. The primary source of water collection in the sector is groundwater, which is exploited through empirically drilled wells, leading to drilling in areas with low water potential. This scenario highlights the need to apply technical and economic strategies to optimize resources. This study aims to delimit areas with groundwater potential through the integrated application of geophysical methods and geological correlation for the optimization of drilling plans. The methodology consists of three phases: (i) analysis of cartographic, geological, and hydrological information, (ii) geophysical prospecting and interpretation using vertical electrical sounding, electrical resistivity tomography, and transient electromagnetic, and (iii) proposed drilling plan. The results revealed low-permeability materials (clays and silts) in the first 15 m, followed by permeable carbonate sandstone units. The correlation between the geoelectric layers and the lithological arrangement corresponds to a 25 m saturated layer with permeable and transmissive materials, which was validated by drilling an extraction well. The combination of methods allowed for greater spatial coverage, a significant reduction in field time, and optimization of resources, offering an efficient alternative for water projects in semi-arid tropical areas with high geological heterogeneity.

Keywords

aquifers, hydrogeological prospecting, electrical resistivity, drilling, water scarcity, vertical electrical sounding (VES), electrical resistivity tomography (ERT), transient electromagnetic (TEM)