Using Surface Time Domain Reflectometry Measurements to Estimate Subsurface Chemical Movement

Date
2003-01-01
Authors
Gaur, Anju
Horton, Robert
Horton, Robert
Jaynes, Dan
Lee, Jaehoon
Al-Jabri, Salem
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Agronomy
Organizational Unit
Journal Issue
Series
Department
Agronomy
Abstract

Chemicals that leach through soil pose threats to surface and groundwater quality. It is difficult and expensive to measure subsurface chemical transport and the transport properties required for extrapolating predictions beyond limited observations. The objective of our study was to evaluate whether solute transport properties measured at the soil surface could be used to predict subsurface chemical movement. The study was conducted in a greenhouse soil pit. The solute transport properties of the surface 2-cm soil layer were determined by using time domain reflectometry (TDR) to measure the bulk electrical conductivity during a step application of CaCl2 solution. The movement of chemicals in the subsurface was measured within the top 30 cm of soil following a pulse input of CaCl2 solution. A comparison of the measured chemical transport properties in the surface and subsurface zones of the soil showed that the parameters were similar. Furthermore, the estimated parameters determined by the surface TDR method were used to predict the chemical concentration distributions within the 30-cm soil layer, and it was found that the centers of mass of predicted chemical distributions were not significantly different from the measured ones. Therefore, the surface TDR measurements could be used to successfully predict subsurface chemical transport within the upper 30 cm of the soil. This surface measurement technique is a promising tool for vadose zone chemical transport studies.

Comments

This article is published as Gaur, Anju, Robert Horton, Dan B. Jaynes, Jaehoon Lee, and Salem A. Al-Jabri. "Using surface time domain reflectometry measurements to estimate subsurface chemical movement." Vadose Zone Journal 2, no. 4 (2003): 539-543. doi: 10.2136/vzj2003.5390. Posted with permission.

Description
Keywords
Citation
DOI
Collections