The survey region is 30 m by 18 m and includes 13 wells. The goal of the surveys is to image the complex fluvial stratigraphy around the wellfield. These images will be used to constrain and construct fine-scale models of permeability and other hydrogeophysical parameters at the site. Depth of penetration ranges from 6 m for the 200 MHz data to 20 m for the 25 MHz data.
Resolution increases with increasing frequency.
Processing significantly improves the reliability and interpretability of the images. Horizontal bedding, cross-bedding and channel structures are clearly evident in the radar images, as are zones of increased scattering and attenuation. The 100 MHz and 200 MHz data image the water table at a depth of 1-2 m. Depth slices and vertical cuts through the data volumes are useful for identifying the local strike and dip of the different architectural elements, and for precisely locating important hydrostratigraphic boundaries. These data are being used to construct a conceptual model of the hydrostratigraphic zonation of the aquifer.