APPLICATION OF A 3D LITHOLOGIC MODEL AND THE DRASTIC APPROACH FOR AQUIFER CHARACTERIZATION IN NORTHEASTERN KENTUCKY

This study aimed to comprehensively understand aquifer characteristics in four counties within Northeastern Kentucky. Remote sensing, spatial analysis, and three-dimensional (3-D) lithologic modeling techniques, the research focused on evaluating groundwater potential in the specified region. The 3-D lithologic modeling techniques, commonly utilized for detailed characterization and modeling of shallow to intermediate aquifers, incorporated lithology data from approximately 250 wells to construct the model using Surfer software. A groundwater flow model was subsequently developed using MODFLOW 6, utilizing the outcomes of the lithologic model. The derived 3-D lithologic model unveiled an intricate shallow to intermediate aquifer system featuring diverse lithologic categories such as clay, clay and sand, shale, sand, sand and gravel, gravel, sandstone, and limestone. This system exhibited a range of hydraulic conductivities, which varied spatially and influenced groundwater flow. The spatial heterogeneity of the aquifer system was evident, with varying hydraulic conductivities in different directions. Hydraulic continuity was depicted through inter-fingering and the connection of sandy materials and fractures in limestone within the aquifer system. Integrating the 3-D model with GIS and DRASTIC models, a groundwater vulnerability map was generated, considering seven hydrogeological factors. Generalized GIS-based hydrogeologic maps were extracted from diverse datasets, including satellite imagery, digital elevation models, soil data, lithological data, and rainfall data. Borehole data validated the results. The resulting groundwater potential map categorized areas into five ranks (Very Low, Low, Moderate, High, and Very High potential) based on availability. The study effectively compared and integrated the 3-D aquifer model and DRASTIC models, providing crucial insights for sustainable groundwater development and management.