Hysteresis During Infiltration and Redistribution in a Soil Column at Different Initial Water Contents
Vachaud, Georges; Thony, Jean‐Louis
Журнал:
Water Resources Research
Дата:
1971
Аннотация:
Experimental results dealing with flow processes involving hysteresis effects in the suction‐water content relationship were obtained on a vertical column of soil submitted to the following successive controlled flow conditions: (1) redistribution of water following a constant head infiltration in an initially air‐dried column. (2) constant head infiltration followed by redistribution, and (3) constant flux infiltration followed by controlled evaporation and redistribution. Water contents were measured by using gamma ray attenuation, and water suctions were obtained simultaneously from 10 pressure transducers distributed along the soil column, each one being connected to a tensiometer. A data acquisition system permitted fully automated measuring sequences. All the data were punched on tape and treated with a computer. Examination of the changes of water content and water suction at a given depth permitted us to obtain precise information on the hysteretic behavior of Ψ (θ). This analysis showed that the scanning curves for a single reversal can be defined uniquely with reference to the transition water content θ<sub>*</sub>, that the independent domain theory appears to be inadequate for describing soil water hysteresis completely, and that k(θ) can be considered practically unique.
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