Ground-penetrating radar surveys for the detection of preferential flow into soils
- 1Agricultural Department, University of Sassari, Viale Italia, 39, 07100 Sassari, Italy
- 2Univ. Lyon, Univ. Claude Bernard Lyon 1, CNRS, ENTPE, UMR5023 LEHNA, F-69518, Vaulx-en-Velin, France
- 3School of Plant and Environmental Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, United State
- 4Council for Agricultural Research and Economics-Agriculture and Environment Research Center (CREA-AA), Via Celso Ulpiani 5, 70125 Bari, Italy
- 5Department of Land, Air and Water Resources, University of California, Davis, CA 95616, United States
Preferential flow is more the rule than the exception, in particular during water infiltration experiments. In this study, we demonstrate the potential of GPR monitoring to detect preferential flows during water infiltration. We monitored time-lapse ground penetrating radar (GPR) surveys in the vicinity of single-ring infiltration experiments and created a three-dimensional (3D) representation of infiltrated water below the devices. For that purpose, radargrams were constructed from GPR transects conducted over two grids (1 m × 1 m) before and after the infiltration tests. The obtained signal was represented in 3D and a threshold was chosen to part the domain into wetted and non-wetted zones, allowing the determination of the infiltration bulb. That methodology was used to detect the infiltration below the devices and clearly pointed at nonuniform flows in correspondence with the heterogeneous soil structures. The protocol presented in this study represents a practical and valuable tool for detecting preferential flows at the scale of a single ring infiltration experiment.
How to cite: Di Prima, S., Winiarski, T., Angulo-Jaramillo, R., Stewart, R. D., Castellini, M., Abou Najm, M. R., Ventrella, D., Pirastru, M., Giadrossich, F., and Lassabatere, L.: Ground-penetrating radar surveys for the detection of preferential flow into soils, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-4177, https://doi.org/10.5194/egusphere-egu2020-4177, 2020
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Hi Simone, a shame that your presentation was not covered in the session, it was really interesting.
I was really impressed with the video that you produced - it was clear, concise and with great data visuals.
I have a question about the preferential flow path. I see that there are a couple of unconnected pools at the bottom of the soil profile. Do you have any idea why this may be?
Thank you!
Hi Martha,
Many thanks for your interest and nice words.
These small patches of wetted soil were likely connected with the infiltration source by small pores. Further investigations are thus needed to better understand the dimensions of flow pathways detectable with GPR, including whether the technology is able to resolve very small fingers or pores.
Here the full manuscript:
https://bestsoilhydro.files.wordpress.com/2020/04/di-prima-et-al-2020_stoten.pdf
Best,
Simone.
Thank you for your response, Simone, I look forward to reading. I am planning on embarking on a GPR study of tropical peatland soils, so this is very helpful.