MAPPING THE WATER TABLE WITH GROUND PENETRATING RADAR IN SHALLOW GROUNDWATER ENVIRONMENTS

In shallow groundwater environments, water table position and its spatiotemporal variations can yield valuable insight into groundwater recharge and discharge dynamics, along with various other hydrologic characteristics of the shallow subsurface. However, beyond the point scale measurements made using observation wells, obtaining spatially continuous water table depth data at the field scale remains a significant challenge. In this study we present our research that aims to advance the use of geophysical methods, especially Ground Penetrating Radar (GPR) that provides a faster, more efficient, and non-destructive way to obtain subsurface data as an alternative approach to water table mapping at the field scale. For the study we collected GPR data in both laboratory soil columns and in complex natural terrains with shallow water tables within the Hamden, Connecticut area using common GPR configurations (i.e. 250 & 500MHz transmitter frequencies and fixed offset transmitter-receiver antennae) to identify instrument requirements, data acquisition configurations, and subsurface geologic conditions that facilitate the use of GPR for water table detection in simple to complex natural settings. Data recordings from the GPR where then viewed and analyzed using the program MALA RadExplorer. Our findings in this study highlight the significant opportunities and potential challenges to using GPR data for shallow water table mapping for various geological and other investigations.