Advancing Regional-Scale High-Resolution Groundwater Modeling: Integrating Borehole and Airborne Geophysical Data and MODFLOW6

Presenter

Frank Tsai, Ph.D.
Professor and Director
Dept. of Civil and Environmental Engineering
Louisiana State University
Baton Rouge, Louisiana

Description

The release of USGS MODFLOW 6 in 2017 introduced a new era in groundwater modeling, offering unstructured grids (DISU) and parallel computing capabilities. This seminar explores how these advancements enable more flexible and accurate groundwater simulations, particularly for complex geological settings where traditional layered grids are limiting. By eliminating the constraints of structured grids, MODFLOW 6 allows researchers to develop more defensible geological models that better represent real-world hydrogeologic conditions. This study presents a data-model workflow that integrates an extensive well log dataset and airborne electromagnetic (AEM) resistivity data to generate high-resolution lithofacies models for MODFLOW 6 applications in the Lower Mississippi-Gulf (LMG) region. The region’s three principal aquifers—coastal lowlands aquifer system (CLAS), Mississippi embayment (MEAS) aquifer system, and Mississippi River Valley alluvial aquifer (MRVA)—are vital freshwater sources for agriculture, public supply, and industry. Additionally, AEM resistivity data provide critical insights into salinization issues affecting the LMG region, Louisiana coastal wetlands, and the Mississippi River. Beyond groundwater management, MODFLOW 6 can be a potential tool for energy transition applications, including assessing the impacts of carbon capture and storage (CCS) and hydrogen storage on drinking water aquifers. The data-model workflow underscores MODFLOW 6’s capabilities for addressing groundwater availability, saltwater intrusion, and land subsidence, making it a powerful tool for tackling hydrogeological and environmental challenges.