TY  - JOUR
AU  - Moghadas, Davood
AU  - Jadoon, Khan Zaib
AU  - Vanderborght, Jan
AU  - Lambot, Sebastian
AU  - Vereecken, Harry
TI  - Estimation of the near surface soil water content during evaporation using air-launched ground-penetrating radar
JO  - Near surface geophysics
VL  - 12
IS  - 5
SN  - 1873-0604
CY  - Houten
PB  - EAGE
M1  - FZJ-2015-03452
SP  - 623-633
PY  - 2014
AB  - Evaporation is an important process in the global water cycle and its variation affects the near surface 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 fullwaveform 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. 
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000347643300006
DO  - DOI:10.3997/1873-0604.2014017
UR  - https://juser.fz-juelich.de/record/201147
ER  -