Application of high-frequency ground penetrating radar to the reconstruction of 3D sedimentary architecture in a flume model of a fluvial system

Ground penetrating radar (GPR) offers a fast and efficient method for visualizing three-dimensional (3D) images of shallow subsurface structures. We investigated the application of GPR to nondestructive imaging of deposits formed in a small experimental flume using a high-frequency GPR antenna. The GPR measurements, made with a 1.6 GHz antenna, were conducted on flume models of sandy fluvial systems. We conducted two experiments, one to reveal the penetration depth and resolution of the GPR antenna and to reconstruct the 3D architecture of fluvial deposits created in a flume, and the other to examine the characteristics of reflection boundaries. The experimental materials were mainly loamy soil. The first experiment showed that a 1.6 GHz antenna was suited to laboratory use, offering a depth resolution of 2–3 cm in full penetration of a bed 15–24 cm thick. GPR scanning yielded an accurate reconstruction of the 3D architecture of a fluvial channel using magnetite marker beds. The second experiment also successfully imaged a 3D architecture using quartz sand instead of magnetite, and loamy soil, which have different relative permittivities. This research shows that GPR is a feasible technique for 3D analysis of experimental flume deposits.