Use of Ground-penetrating Radar to Characterize Hydrostratigraphic Units Within a Georgia Coastal Plain Province

Proceedings of the 1997 Georgia Water Resources Conference, March 20-22, 1997, Athens, Georgia.The fate of pesticides/herbicides in a watershed depends upon important hydrologic pathways. In the Coastal Plain of Georgia, the presence and extent of semi-confining lithologic layers dictates the potential for contaminant movement into the local water table. This study used ground penetrating radar to characterize subsurface hydrostratigraphic units on a Coastal Plain study site. Groundwater monitoring wells were installed at various locations at the site, and soil samples were collected and described. The site lithology is characterized by a fine grained quartz sand which is underlain by a clay-rich indurated sandy loam (CRISL). These soil samples are only point descriptions and do not describe the continuity of the layer. Therefore, ground penetrating radar was utilized to map the lithological features of the CRISL and determine the continuity of this layer. Analysis of the ground penetrating radar data suggests the CRISL (semi-confining layer) is discontinuous, and the discontinuity is elongated at the region along the ephemeral stream that drains the watershed. This geometry may be used to accurately illustrate unsaturated/saturated flow in a contaminant transport model.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602 with partial funding provided by the U.S. Department of Interior, Geological Survey, through the Georgia Water Research Institutes Authorization Act of 1990 (P.L. 101-397). The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of the University of Georgia or the U.S. Geological Survey or the conference sponsors