Evaluación de la vulnerabilidad intrínseca a la contaminación mediante técnicas multivariables en el acuífero costero de Olón

Abstract

Groundwater is a vital source, especially in arid regions. In Olón, the recent growth in water demand requires hydrogeological studies to ensure the sustainability of the aquifer. This study aims to generate maps that zone the areas most vulnerable to contamination for the formulation of sustainability strategies. The DRASTIC index and the protection capacity of the aquifer were obtained from geoelectric tests and well data. The results indicate that 73% of the aquifer is highly vulnerable during the rainy season, due to shallow water tables, high permeability of the vadose zone and high recharge that facilitates the infiltration of contaminants. In the dry season, vulnerability decreases, but persists in some areas. Water wells are highly susceptible due to the low attenuation capacity of contaminants in the sandy surface layers. The aquifer has moderate protection due to the thin thickness of the overburden layer. The analysis in a GIS environment allowed to identify critical areas with a higher risk of contamination. Sustainable strategies were proposed, such as the implementation of green filters, the construction of dams using ancestral techniques, and activities focused on raising awareness about water consumption. Keywords: intrinsic vulnerability, DRASTIC, longitudinal conductance, geoelectrical tests