20 Hydrogeology and Marine/Coastal Geoscience

This session covers aspects related to SGDs & their associated aquifers, including but not limited to: water–rock interaction, coastal aquifer contamination, geochemical transformation, hydrological flows, saline intrusion, coastal estuaries, and environmental, economic, and social SGD-related issues.

Thursday, 23 April 2026
8:00 AM - 10:00 AM
LMH, Meeting Room

Delineation of flow components in a tropical karst groundwater flow system located in southeastern Mexico in a zone of Submarine Groundwater Discharge zone

Paper number: 20-3
Program: Technical Sessions
Time: 8:45 AM – 9:00 AM

Authors

Abstract

Mexico has 29 groundwater flow systems (GFS) that discharge groundwater into the sea. These GFS present different flow components or flow trajectories related to the geology of the subsoil and the anthropogenic influence on them. Despite the hydrogeological importance, these GFS are poorly characterized in terms of flow components, especially the Yucatan GFS, located in the southeastern part of Mexico in the tropical karst zone. The object of this study is to delimit the flow components in the Yucatan GFS. The methodology consisted of a field sampling campaign of 80 wells in May of 2023, and multivariate statistical and hydrogeochemical analyses. The main results show the presence of three flow components: 1) local component, characterized by HCO₃⁻-Ca type water with recent recharge, 2) intermediate SO₄²⁻ component associated with gypsum dissolution and flow path modification induced by faults and 3) intermediate Cl⁻ component resulting from mixing with seawater along the coastal zone. The geology—particularly the presence of evaporitic rocks and tectonic structures—controls hydrogeochemical evolution and flow pathways, while the intense precipitation of the tropical climate modulates recharge and promotes the system’s rapid response. This work represents the first delineation of groundwater flow system components in a tropical carbonate region of Mexico associated to the Submarine Groundwater Discharge and constitutes a significant advance for sustainable groundwater management in complex karst environment.

Geological Society of America Abstracts with Programs. Vol. 58, No. 3

doi: 10.1130/abs/2026CD-410801

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