HR: 10:50h
AN: H32A-03 [Abstracts]
TI: 3D Flow of Water Through the Undisturbed Samples of Coarse Sandy Loam Visualized by MRI
AU: * Cislerova, M
EM: cislerova@fsv.cvut.cz
AF: CTU Prague, Faculty of Civil Engineering, Takurova 7, Prague 6, 166 29
Czech Republic
AU: Snehota, M
EM: snehota@fsv.cvut.cz
AF: CTU Prague, Faculty of Civil Engineering, Takurova 7, Prague 6, 166 29
Czech Republic
AU: Amin, G M
EM: Gao Amin
AU: Hall, L D
EM: ldh11@hslmc.cam.ac.uk
AF: HSLMC, University of Cambridge, University Forvie Site,
Robinson Way, Cambridge, CB2 2PZ
United Kingdom
AB:
The filling of pores of undisturbed soil samples (each 9 cm of diameter and 8.5 cm height) of coarse sandy loam (Korkusova
Hu_, CR) was monitored under changing flow conditions using 3D nuclear magnetic resonance imaging (MRI). The soil under study
represents a heterogeneous porous medium of random structure. The flow in the particular samples was imaged during recurrent
ponded infiltration-outflow and tension infiltration-outflow experiments. The boundary condition at the top of the samples
was maintained by means of the disc infiltrometer. Free outflow was used as the bottom boundary condition. Pressure head was
measured by tensiometer installed in the body of each sample. Values of hydraulic pressure heads, sample weights and
cumulative flow data were recorded during the experiments. At the saturation and near-saturation stages, significant
preferential flow was observed together with the instability of steady state flow rates. From the MRI videos of water
propagation throughout the samples it is evident, that the flow instability has been caused due to air phase redistribution.
Questionable is the role of several order differences of local pore velocity values and its impact on the filling of the
sample within the time scale of the experiment.
DE: 1875 Unsaturated zone
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting