TY  - CONF
AU  - Merz, Steffen
AU  - Pohlmeier, Andreas
AU  - Vanderborght, Jan
AU  - van Dusschoten, Dagmar
AU  - Vereecken, Harry
TI  - Transition of Stage I to Stage II evaporation regime in the topmost soil: High-resolution NMR imaging, profiling and numerical simulation
JO  - Microporous and mesoporous materials
VL  - 205
SN  - 1387-1811
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2014-05703
SP  - 3-6
PY  - 2015
AB  - Bare soils are natural porous media where moisture and transport properties may change considerably. Under very dry conditions, it is predicted that capillary continuity from deeper soil layers to the surface ceases and evaporation decreases drastically because it is only sustained by vapor transport through an increasing dry surface layer (stage II). In this study, we firstly confirm this effect by investigating the drying of a lab-scale sand column using various MRI sequences as well as a unilateral NMR sensor (NMR-MOUSE). Proofing the convenience of the unilateral sensor, we take a step forward by monitoring moisture development of a natural soil under controlled ambient conditions. Finally, the experimental results clearly validate the prediction of a coupled water, vapor and heat flow model regarding the onset of stage II evaporation and the subsequent receding secondary evaporation front.
T2  - 12th International Bologna Conference on Magnetic Resonance in Porous Media (MRPM12)
CY  - 9 Feb 2014 - 13 Feb 2014, Wellington (New Zealand)
Y2  - 9 Feb 2014 - 13 Feb 2014
M2  - Wellington, New Zealand
LB  - PUB:(DE-HGF)8 ; PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000350190500002
DO  - DOI:10.1016/j.micromeso.2014.10.035
UR  - https://juser.fz-juelich.de/record/172214
ER  -