Estimation of the near surface soil water content during evaporation using air-launched ground-penetrating radar

Davood Moghadas, Khan Jadoon, Jan P. Vanderborght, Sébastien Lambot, Harry Vereecken

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Evaporation is an important process in the global water cycle and its variation affects the near sur-face soil water content, which is crucial for surface hydrology and climate modelling. Soil evaporation rate is often characterized by two distinct phases, namely, the energy limited phase (stage-I) and the soil hydraulic limited period (stage-II). In this paper, a laboratory experiment was conducted using a sand box filled with fine sand, which was subject to evaporation for a period of twenty three days. The setup was equipped with a weighting system to record automatically the weight of the sand box with a constant time-step. Furthermore, time-lapse air-launched ground penetrating radar (GPR) measurements were performed to monitor the evaporation process. The GPR model involves a full-waveform frequency-domain solution of Maxwell's equations for wave propagation in three-dimensional multilayered media. The accuracy of the full-waveform GPR forward modelling with respect to three different petrophysical models was investigated. Moreover, full-waveform inversion of the GPR data was used to estimate the quantitative information, such as near surface soil water content. The two stages of evaporation can be clearly observed in the radargram, which indicates qualitatively that enough information is contained in the GPR data. The full-waveform GPR inversion allows for accurate estimation of the near surface soil water content during extended evaporation phases, when a wide frequency range of GPR (0.8-5.0 GHz) is taken into account. In addition, the results indicate that the CRIM model may constitute a relevant alternative in solving the frequency-dependency issue for full waveform GPR modelling.
Original languageEnglish (US)
Pages (from-to)623-634
Number of pages12
JournalNear Surface Geophysics
Volume12
Issue number5
DOIs
StatePublished - Aug 11 2014

ASJC Scopus subject areas

  • Geophysics

Fingerprint Dive into the research topics of 'Estimation of the near surface soil water content during evaporation using air-launched ground-penetrating radar'. Together they form a unique fingerprint.

Cite this