Crosshole radar and resistivity tomography

摘要

Ground Penetrating Radar (GPR) and Electrical Resistivity Tomography (ERT) are used from the same boreholes (GeoWells) to image the subsurface electrical properties at a Vermont test site. The Cone Penetrometer Technique (CPT) logged the boreholes and installed GeoWells to a depth of 70 feet. The CPT logs included soil properties, such as, soil type, pore pressure and resistivity. Prior to the CPT pushes, surface GPR surveys mapped the stratigraphy of the inter-bedded sand and clay layers to a depth of 20 feet. We used these maps to select the location of four GeoWells (on the corners of a square) and two monitoring wells. An infusion well, screened from the 12- to 15-foot depth, near the center of the GeoWell pattern, allowed injection of about 100gallons of saline water into the vadose zone (the water table is at 160 feet).