Applying resistivity (dipole-dipole, Schlumberger, and Wenner) joint inversion to detect endokarst features in Quintana Roo, México

Abstract

The state of Quintana Roo is part of the Yucatan Peninsula (YP), a platform formed by calcareous sediments. The joint action of erosion, transport, and sedimentation processes by surface and underground water on limestone results in a structure known as karst. Karst systems are typically characterized by lack of surface water due to high infiltration, presence of sinkholes and caves, and groundwater flow through carbonates that over time create long channels and caverns by rock dissolution. According to the literature the main source of freshwater in the Yucatan Peninsula is a regional aquifer. Hydrogeological models explain this aquifer as a thin freshwater lens floating over seawater, and the thickness of this freshwater lens varies with proximity to the coast. Ongoing population growth in Quintana Roo has increased demand for freshwater, and the only source of water there is found underground. Geophysical exploration methods are important for obtaining information on the structure of the subsoil, which is fundamental for developing flow models and estimating water availability, thus enabling us to carry on with sustainable water management. In this study, we apply a two-dimensional joint and separate inversion of data with dipole-dipole, Schlumberger, and Wenner configurations on real and synthetic data. We show that joint inversion is better than using separate inversions because the joint inversion uses a higher density of data and different current distribution in the subsoil. The high heterogeneity of karstic environments can be better detected if more information on the subsoil is obtained, allowing for more precise interpretations.