HR: 16:20h
AN: H44B-04 INVITED     [Abstracts]
TI: Soil Hydraulic Parameters for Heterogeneous Landscapes
AU: * Mohanty, B P
EM: bmohanty@tamu.edu
AF: Texas A&M University, 2117 TAMU, College Station, TX 77843 United States
AU: Zhu, J
EM: jianting.zhu@dri.edu
AF: Desert Research Institute, Division of Hydrologic Science 755 E. Flamingo Rd., Las Vegas, NV 89119 United States
AB: A priori parameter estimation for distributed hydrologic models remains to be a challenging issue in hydrology. Spatio-temporal heterogeneity/nonlinearity of hydrologic parameters, between-parameter correlations, basin characteristics, flux gradient/direction, and time-varying boundary conditions are some of the key factors compounding the effect of parameter uncertainty. Although no unique parameter estimation scheme exists to account for all hydrologic scenarios, recent advances including the guidelines for developing "effective" hydrologic parameters will be reviewed in this talk. Examples of transfer functions translating pedologic, topographic, and vegetation attributes to soil hydraulic properties for Southern Great Plains region will be presented. Additionally, new schemes for deriving "effective" soil hydraulic parameter for steady state flow in heterogeneous soils will be presented. "Effective" soil hydraulic parameters of the heterogeneous soil formation are obtained by conceptualizing the soil as an equivalent homogeneous medium. It requires that the "effective" homogeneous soil discharges the same mean surface moisture flux (evaporation or infiltration) as the heterogeneous media. Assuming one-dimensional vertical moisture movement in the unsaturated soils, both scenarios of horizontal (across the land surface) and vertical (across the soil profile) heterogeneities are investigated. The effects of hydraulic parameter statistics, surface boundary conditions, domain scales and fractal dimensions in case of nested soil hydraulic property structure will be addressed.
DE: 1818 Evapotranspiration
DE: 1833 Hydroclimatology
DE: 1836 Hydrologic budget (1655)
DE: 1869 Stochastic processes
SC: Hydrology [H]
MN: 2005 Joint Assembly