Equation for Describing Solute Transport in Field Soils with Preferential Flow Paths
Young-Jin Kima,
Christophe J. G. Darnaultb,
Nathan O. Baileyd,
J.-Yves Parlangec and
Tammo S. Steenhuisc,*
a Dep. of Biological and Environmental Engineering, Riley-Robb Hall, Cornell Univ., Ithaca, NY 14853, currently at Environmental Sciences Division, Oak Ridge National Lab., Oak Ridge, TN 37831
b Dep. of Civil and Materials Engineering, Univ. of Illinois at Chicago, Chicago, IL 60607
c Dep. of Biological and Environmental Engineering, Riley-Robb Hall, Cornell Univ., Ithaca, NY 14853
d Biological and Agricultural Systems Engineering, Florida A&M Univ., Tallahassee, FL 32307

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Fig. 1. Schematic diagram of the flow process in the soil with preferential flow paths.
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Fig. 2. Schematic illustration of the experimental setup.
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Fig. 3. Chloride breakthrough curves (BTCs) for undisturbed soil columns: (a) as a function of cumulative drainage, and (b) as a function of time (Exp. 1). The BTCs rising limbs for sand columns: (c) as a function of cumulative drainage, and (d) as a function of time. The BTCs falling limbs for sand columns: (e) as a function of cumulative drainage, and (f) as a function of time (Exp. 2). The BTCs for sand columns with chloride applied on the surface of the column: (g) as a function of cumulative drainage, and (h) as a function of time (Exp. 3). For (a) and (b), S represents the point where the rain with Cl was switched to regular acid rain. For (e) and (f), the y axis indicates the time after switching to the regular rain. C1 and C2 refer to Columns 1 and 2, respectively.
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Fig. 4. The number of fingers created at a depth of 14 cm with different flow rates. The left picture was taken after the rainfall rate of 0.3 cm/h during the third set of experiments (three fingers were delineated with a marker for convenience). The picture on the right is for the 1.8 cm/h of rainfall intensity in the second set of experiments. Under the higher rate of rain, fingers merged in the center of the column (dark area), but the outer edge of the column was still dry (bright area).
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Fig. 5. Fitting results of the Generalized Preferential Flow Model (GPFM) and the Convective-Dispersive (CD) model for undisturbed soil Column 1 with the high rate (Exp. 1).
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Fig. 6. Fitting results of the Generalized Preferential Flow Model (GPFM) and the Convective-Dispersive (CD) model for sand Column 1 with the high rate (Exp. 2).
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Fig. 7. Fitting results of Generalized Preferential Flow Model (GPFM) and the Convective-Dispersive (CD) model for sand Column 1 with 1 cm/h rain (Exp. 3).
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Fig. 8. The water content in the distribution zone plotted as a function of the flux.
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Copyright © 2005 by the Soil Science Society of America.