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ARS Home » Southeast Area » Oxford, Mississippi » National Sedimentation Laboratory » Watershed Physical Processes Research » Research » Publications at this Location » Publication #415138
Research Project: Acoustic and Geophysical Methods for Multi-Scale Measurements of Soil and Water Resources

Location: Watershed Physical Processes Research

Title: Groundwater site investigation using geophysical methods: A study at Goodwin Creek watershed

Author
item BUSKES, ELSIE - University Of Mississippi
item WODAJO, LETI - University Of Mississippi
item ALIM, MD SAMIUL - University Of Mississippi
item HICKEY, CRAIG - University Of Mississippi
item O'Reilly, Andrew - Andy

Submitted to: Symposium on Application of Geophysics to Engineering and Environmental Problems Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/24/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Rapid, unchecked population growth, rising quality of life, and increasing demand for food and energy all increase stress levels on our limited groundwater resources. Changing precipitation patterns, groundwater recharge, and increasing extremes of flooding and drought are among the most tangible impacts of climate change on sustainable groundwater resources and underscore the need to address the water scarcity problem. Groundwater depletion increases the need to improve the characterization of subsurface heterogeneity and identify optimal locations and approaches for the placement of groundwater extraction and monitoring wells. In this study, two surface-based geophysical methods, electrical resistivity tomography (ERT) and electromagnetic induction (EMI), are used for subsurface characterization and delineation of aquifers at a United States Department of Agriculture hydrologic research site encompassing a creek and a pasture. The study site is in the Goodwin Creek Experimental Watershed in Panola County, Mississippi. A 501-meter long electrical resistivity tomography (ERT) survey at 3-meter electrode spacing was conducted to characterize the subsurface heterogeneity and delineate the depth and thickness of the aquifer. An electromagnetic induction (EMI) survey was conducted using an EM31 instrument over a larger area to provide greater spatial coverage of the site. Disturbed and undisturbed soil samples were collected at different locations to determine soil properties and help interpret geophysical results. A comparison of electrical resistivity tomography (ERT) and an electromagnetic induction (EMI) results showed consistent results where high resistivity values on the electrical resistivity tomography (ERT) are indicated with low conductivity on the electromagnetic induction (EMI) map. Electrical resistivity tomography (ERT) results indicate that the aquifer thickness varies between less than 10 meters near the creek and greater than 30 meters in the pasture, with variable depths to the top of the aquifer. Results from this study show the advantages and capabilities of surface-based geophysical methods to delineate aquifers and identify optimal well locations, leading to improved groundwater management and minimizing well failures due to poor well placement.