|
|
||||||||
Institute for Land and Water Management, Katholieke Universteit Leuven, Vital Decosterstraat 102, 3000 Leuven, Belgium
*Corresponding author (jan.vanderborght{at}agr.kuleuven.ac.be).
ABSTRACT
Time Domain Reflectometry (TDR) has become a popular method to obtain time series of resident concentrations in solute transport studies, so effective interpretation of TDR data is very useful. In this study, we evaluated three procedures to determine the parameters of the convective lognormal transfer function (CLT) model from such time series. In a first approach, the CLT model travel time probability density function (pdf) was related to time series of time-integral-normalized flux concentrations, Cf*(z,t). The normalization was based on mass balance calculations performed with time series of resident concentrations measured at several depths. The Cf*(z,t) data thus obtained were very erratic leading to a high parameter uncertainty. In a second approach, the CLT model travel depth pdf was related to time series of depth-integral- or mass-normalized resident concentrations, Crm*(z,t). This approach suffered from uncertainty regarding calibration coefficients relating TDR measured impedance to resident concentrations and from uncertainty regarding the solute mass crossing the sampling volume of the TDR probe. The third approach used the relation between travel time and travel depth pdf for a stochastic-convective transport process to formulate a new expression relating time-integral-normalized resident concentrations, Crt*(z,t), to the CLT model parameters. No information is needed about calibration coefficients while no a priori assumptions about the solute mass detected by the TDR probe are required. This approach yielded better CLT model fits to observed concentration data, and the variability of parameters fitted at different locations can be related to heterogeneity of solute and water flow after averaging across the TDR measurement window.
Received for publication November 21, 1994.
This article has been cited by other articles:
![]() |
M. Javaux, J. Vanderborght, R. Kasteel, and M. Vanclooster Three-Dimensional Modeling of the Scale- and Flow Rate-Dependency of Dispersion in a Heterogeneous Unsaturated Sandy Monolith Vadose Zone J., April 27, 2006; 5(2): 515 - 528. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Gaur, R. Horton, D. B. Jaynes, and J. L. Baker Measured and Predicted Solute Transport in a Tile Drained Field Soil Sci. Soc. Am. J., April 19, 2006; 70(3): 872 - 881. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Noborio, R. G. Kachanoski, and C. S. Tan Solute Transport Measurement Under Transient Field Conditions Using Time Domain Reflectometry Vadose Zone J., March 8, 2006; 5(1): 412 - 418. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Javaux and M. Vanclooster In Situ Long-Term Chloride Transport through a Layered, Nonsaturated Subsoil. 1. Data Set, Interpolation Methodology, and Results Vadose Zone J., November 1, 2004; 3(4): 1322 - 1330. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Javaux and M. Vanclooster Scale- and Rate-Dependent Solute Transport within an Unsaturated Sandy Monolith Soil Sci. Soc. Am. J., September 1, 2003; 67(5): 1334 - 1343. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. O. Gasser, J. Caron, R. Lagace, and M. R. Laverdiere Predicting Nitrate Leaching under Potato Crops Using Transfer Functions J. Environ. Qual., July 1, 2003; 32(4): 1464 - 1473. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Javaux and M. Vanclooster Robust Estimation of the Generalized Solute Transfer Function Parameters Soil Sci. Soc. Am. J., January 1, 2003; 67(1): 81 - 91. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. O. Gasser, J. Caron, M. R. Laverdiere, and R. Lagace Solute Transport Modeling under Cultivated Sandy Soils and Transient Water Regime J. Environ. Qual., September 1, 2002; 31(5): 1722 - 1730. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Nadler, S. R. Green, I. Vogeler, and B. E. Clothier Horizontal and Vertical TDR Measurements of Soil Water Content and Electrical Conductivity Soil Sci. Soc. Am. J., May 1, 2002; 66(3): 735 - 743. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Garrido, M. Ghodrati, C. G. Campbell, and M. Chendorain Detailed Characterization of Solute Transport in a Heterogeneous Field Soil J. Environ. Qual., March 1, 2001; 30(2): 573 - 583. [Abstract] [Full Text] [PDF] |
||||
![]() |
R. Zhang Generalized Transfer Function Model for Solute Transport in Heterogeneous Soils Soil Sci. Soc. Am. J., September 1, 2000; 64(5): 1595 - 1602. [Abstract] [Full Text] |
||||
![]() |
H.H. Nissen, P. Moldrup, and R.G. Kachanoski Time Domain Reflectometry Measurements of Solute Transport across a Soil Layer Boundary Soil Sci. Soc. Am. J., January 1, 2000; 64(1): 62 - 74. [Abstract] [Full Text] |
||||
![]() |
J. Caron, S.B. Jemia, J. Gallichand, and L. Trepanier Field Bromide Transport under Transient-State: Monitoring with Time Domain Reflectometry and Porous Cup Soil Sci. Soc. Am. J., November 1, 1999; 63(6): 1544 - 1553. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||