HR: 17:15h
AN: H12K-06    [PDF]
TI: A Multi-Functional Heat Pulse Probe for Simultaneous Measurement of Water, Heat, and Solute Transport in the Vadose Zone
AU: * Mortensen, A P
EM: apm@geo.geol.ku.dk
AF: Annette Pia Mortensen, Geological Institute, Oster Voldgade 10, Copenhagen, 2100 Denmark
AU: Mori, Y
EM: yasushim@life.shimane-u.ac.jp
AF: Yasushi Mori, Life and Environmental Science, Shimane University, Matsue, 690-8504 Japan
AU: Hopmans, J W
EM: jwhopmans@ucdavis.edu
AF: Jan W. Hopmans, Dept Land, Air and Water Resources, 123 Veihmeyer Hall, University of California, Davis, CA 95616 United States
AU: Simunek, J
EM: JSimunek@ussl.ars.usda.gov
AF: Jirka Simunek, USDA-ARS George E. Brown, Jr. Salinity Lab, 450 W Big Springs Rd, Riverside, CA 92507-4617 United States
AB: A small multi-functional heat pulse probe (MFHPP) for vadose zone measurements was developed and tested in the laboratory. The probe combines a heat pulse technique for estimating soil heat properties, water flux, and water content with a Wenner array measurement of electrical conductivity (EC). The probe thus provides a simultaneous estimate of water, heat, and solute transport parameters at the same location and spatial scale. To test the MFHPP, highly controlled steady-state flow column experiments in sand were conducted over a wide range of saturations, flow velocities, and EC concentrations. The data were analyzed using the modified HYDRUS model, which includes an option for inverse modeling of simultaneous water, vapor, heat, and solute transport. The inverse estimated parameters included volumetric heat capacity, thermal conductivity, heat dispersion, water flux, moisture content, and solute dispersion. The performance of the MFHPP was compared and evaluated with independently measured data. Thermal properties, including thermal conductivity and thermal diffusivity, compared well with previously measured data for the sand. Water contents between 0.2 and 1.0 were estimated at both static and steady-stay flow conditions with a RMSE of 0.016 cm$^{3}$ cm$^{-3}$. Water fluxes were estimated successfully for both saturated and unsaturated conditions within a range of 2.0E-06 m/s to 7.2E-05 m/s. Solute breakthrough curves at different water contents were analyzed and the solute and thermal dispersivities were compared. The probe constitutes a new promising vadose zone measurement technique for combined heat and solute transport estimation and for water flux and dispersion measurements.
DE: 1800 HYDROLOGY
DE: 1866 Soil moisture
DE: 1875 Unsaturated zone
DE: 1894 Instruments and techniques
SC: Hydrology [H]
MN: 2003 Fall Meeting