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Monitoring Moisture Migration in the Vadose Zone Using Electrical Resistivity Techniques.

Waller MJ; Kean WF; Layson HR
BoM, 1986 :94 pages
Surface resistivity techniques were used at four field sites to monitor changes in apparent resistivities with variations in soil moisture content in the vadose zone. Apparent resistivity values were correlated with gravimetric moisture contents from soil samples taken at each site. Tensiometer readings were taken at two sites and correlated with the results of gravimetric moisture contents and apparent resistivities. Mositure at two of the sites was added by extensive watering; rainfall events were monitored at the other two sites. A recharge event at a dewatering program was monitored at a fifth site. A ghosh-koefed multilayer computing algorithm was used to derive true resistivities from bulk or apparent resistivities. An automated data acquisition system was developed to measure resistivity changes and to process the data in the field. These studies are the first to evaluate measurement of moisture migration in clay rich soils using surface resistivity techniques. Results indicate that surface resistivity techniques readily measure changes in moisture contents in the vadose zone in clay rich soils. Correlation of apparent and true resistivity values with gravimetric moisture contents is more complex and requires additional research.
Publication Date
Document Type
CP; Final Contract Report;
Fiscal Year
NTIS Accession No.
NTIS Price
Identifying No.
OFR 93-86
NIOSH Division
Source Name
Bureau of Mines
Performing Organization
Earth Tech, Inc.
Page last reviewed: November 19, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division