HR: 0800h
AN: H51C-0644    [Abstracts]
TI: Estimation of Soil Hydraulic Parameters From Ring Infiltration Measurements by a Method Based on the Scaling of Dimensionless Numerical Solutions to the 3-D Axisymmetric Richards' Equation
AU: * Soria Ugalde, J M
EM: josesoria@quijote.ugto.mx
AF: Facultad de Ingenieria en Geomatica e Hidraulica. Universidad de Guanajuato., Av. Juarez No. 77, Zona Centro, Guanajuato, Gto 36000, Mexico
AU: Angulo-Jaramillo, R
EM: rafael.ANGULO@entpe.fr
AF: Laboratoire de Sciences de l'Environnement, Ecole Nationale des Travaux Publiques de l'Etat., Rue Maurice Audin, Vaulx-en-Velin Cedex, 69518, France
AU: Haverkamp, R
EM: haverkamp@hydrowide.com
AF: Hydrowide, Domaine Universitaire B.P. 53, St. Martin d'Heres, 38041, France
AB: A method is developed to estimate the soil hydraulic parameters using simple ring infiltration tests, assuming that the 3-D axisymmetric Richards equation governs the water movement within a soil. In this method, measured volumes of infiltration vs time, VI-t, are matched by scaled dimensionless volumes, VI*-t*, calculated numerically. To do so, the method utilizes a similar approach to that of the "Beerkan method" (Haverkamp et al., 1996) which assumes that the shape parameter(s) of the hydraulic conductivity and water retention curves, can be obtained from textural information and other easy-to-collect data. Then, we show that the two scaling factors making possible to pass from the dimensionless solution to the measured infiltration signal are only dependent on: i) the hydraulic conductivity at saturation (K_s), and ii) the normalisation parameter of the water retention curve (h_ae). We test the method numerically and for experimental data of two contrasting soils: a well graded silt and a structured coarse sand, both having null pressure heads at the surface and uniform initial water contents. The results indicate that good estimations of the parameters K_s and h_ae can be obtained, although they are dependent upon accurate estimations of the shape parameter(s).
DE: 1838 Infiltration
DE: 1866 Soil moisture
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: 2007 Fall Meeting