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Determining the Hydraulic Properties of a Swelling Soil from a Transient Evaporation Experiment
Author(s) -
Garnier P.,
Rieu M.,
Boivin P.,
Vauclin M.,
Baveye P.
Publication year - 1997
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1997.03615995006100060003x
Subject(s) - hydraulic conductivity , soil water , soil science , deformation (meteorology) , water content , shrinkage , water retention curve , anisotropy , outflow , inverse , geotechnical engineering , transient (computer programming) , flow (mathematics) , evaporation , environmental science , mechanics , materials science , geology , mathematics , thermodynamics , composite material , geometry , physics , optics , computer science , oceanography , operating system
Most methods used to determine the hydraulic properties of swelling soils (i.e., the shrinkage curve [ e (θ)], the moisture retention curve [ h (θ)], and the hydraulic conductivity curve [ K (θ)]) are time consuming because they require measurements of several different parameters (either in separate experiments or by using very expensive equipment). We propose a simple evaporation experiment to simultaneously determine all three soil hydraulic properties. The method is illustrated using samples of a Vertisol from the Senegal River valley. The value of e (θ) is determined during the experiment by horizontal and vertical linear deformation measurements, whereas an inverse parameter estimation method is used to determine h (θT) and K (θ). This method relies on a water flow model that takes into account the three‐dimensional and anisotropic deformation of the soil. The reliability of the estimated parameter values was checked and we compared the results with those obtained by a multistep outflow experiment. Good agreement was found between the results of the different procedures. The sensitivity of the method to deformation was also analyzed. In the soil investigated, the inverse method does not seem to require the use of a water flow model that takes into account deformation. However, a correction for deformation is needed if the characteristic functions are sought in terms of the volumetric water content of the soil.