American Geophysical Union Become an AGU Member
Subscribe to AGU Journals		 AGU Home AGU Publications

Read Full Article (file size: 663560 bytes)    Cited by

WATER RESOURCES RESEARCH, VOL. 41, W04015, doi:10.1029/2004WR003379, 2005

Estimating soil hydraulic parameters from transient flow experiments in a centrifuge using parameter optimization technique

Jirka Šimůnek

Department of Environmental Sciences, University of California, Riverside, California, USA


John R. Nimmo

U.S. Geological Survey, Menlo Park, California, USA


Abstract

A modified version of the Hydrus software package that can directly or inversely simulate water flow in a transient centrifugal field is presented. The inverse solver for parameter estimation of the soil hydraulic parameters is then applied to multirotation transient flow experiments in a centrifuge. Using time-variable water contents measured at a sequence of several rotation speeds, soil hydraulic properties were successfully estimated by numerical inversion of transient experiments. The inverse method was then evaluated by comparing estimated soil hydraulic properties with those determined independently using an equilibrium analysis. The optimized soil hydraulic properties compared well with those determined using equilibrium analysis and steady state experiment. Multirotation experiments in a centrifuge not only offer significant time savings by accelerating time but also provide significantly more information for the parameter estimation procedure compared to multistep outflow experiments in a gravitational field.

Received 28 May 2004; accepted 7 February 2005; published 27 April 2005.

Keywords: centrifuge; Hydrus-1D; soil hydraulic properties; parameter estimation.

Index Terms: 1847 Hydrology: Modeling; 1849 Hydrology: Numerical approximations and analysis; 1894 Hydrology: Instruments and techniques: modeling; 1875 Hydrology: Vadose zone; 1866 Hydrology: Soil moisture.

Read Full Article (file size: 663560 bytes)    Cited by

Citation: Šimůnek, J., and J. R. Nimmo (2005), Estimating soil hydraulic parameters from transient flow experiments in a centrifuge using parameter optimization technique, Water Resour. Res., 41, W04015, doi:10.1029/2004WR003379.