HR: 17:45h
AN: H34D-08    [Abstracts]
TI: Significance of Hydraulic Parameter Distribution Skewness on Effective Averaging Schemes in Heterogeneous Soils
AU: * Zhu, J
EM: jzhu@cora.tamu.edu
AF: Texas A&M University, Department of Biological and Agricultural Engineering, 301B Scoates Hall, Texas A&M University, College Station, TX 77843-2117 United States
AU: Mohanty, B P
EM: bmohanty@tamu.edu
AF: Texas A&M University, Department of Biological and Agricultural Engineering, 301C Scoates Hall, Texas A&M University, College Station, TX 77843-2117 United States
AB: We examined the impact of skewness (third order moment) of hydraulic parameter distributions, which was not considered in most previous studies, on effective soil hydraulic parameter averaging schemes for steady state vertical flow in heterogeneous soils. The effective soil hydraulic parameter of the heterogeneous soil formation is obtained by conceptualizing the soil as an equivalent homogeneous medium. The averaging scheme requires that the effective homogeneous soil discharge the ensemble flux. Using three widely used unsaturated hydraulic conductivity functions (i.e., Gardner, Brooks and Corey and van Genuchten) and various types of the probability distribution functions to represent variability for the nonlinear shape factor in the hydraulic conductivity function, $\alpha$, we derive the effective value for the parameter $\alpha$. Results show that distribution skewness is important in quantifying the effective parameters in addition to the commonly used mean and variance and therefore should be given more attention in future studies.
DE: 3367 Theoretical modeling
DE: 1833 Hydroclimatology
DE: 1836 Hydrologic budget (1655)
DE: 1869 Stochastic processes
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting