Mapping Groundwater Potential Zones for Sustainable Agricultural Development in Entre Ríos, Ecuador

Abstract

In semi-arid areas, groundwater plays a fundamental role in the agricultural development of rural communities. The Entre Ríos commune, southwest of Santa Elena, lacks surface water resources for the development of local agriculture, which is why the population seeks to delineate Groundwater Potential Zones (GWPZ) that allow agricultural reactivation. The focus of this study is to generate a map of the potential of the local hydrogeological resource through geological and geoelectrical campaigns (Transient Electromagnetic Sounding and Vertical Electrical Sounding), in addition to the multi-criteria decision method based on the Analytical Hierarchy Process (AHP) and its integration using Geographic Information Systems (GIS), for the establishment of rural sustainability strategies. The GWPZ demarcation used six thematic layers: lithology, resistivity, texture, slope, drainage density and precipitation. The study identified "very high" GWPZ in the area's northeastern (La Seca) and central-south (Santo Tomás) sectors. These areas have coastal aquifer thicknesses of 10 and 5 meters, respectively, and are mainly related to medium to coarse sand lithologies, with 20 to 80 Ωm resistivities. The strategic proposal aligns with SDGs 2, 6, 8, and 12. It includes water sowing and harvesting techniques, water monitoring, and wastewater management with green filters to benefit the agricultural sector.