HR: 0800h
AN: H31F-1352    [Abstracts]
TI: Application of Electromagnetic Induction Sensors for Mapping the Subsurface in Small Watersheds.
AU: * Robinson, D A
EM: darobinson@cc.usu.edu
AF: Stanford University, Dept of Geophysics, 397 Panama Mall , Stanford, CA 94305-2215 United States
AU: Seyfried, M S
EM: mseyfrie@nwrc.ars.usda.gov
AF: Northwest Watershed Research Center USDA-ARS, 800 PARK BLVD., STE 105 , Boise, ID 83712-7716 United States
AU: Urdanoz, V
EM: vurdanoz@aragon.es
AF: Unidad de Suelos y Riegos, SIA-DGA, Apartado 727, , Zaragoza, 50080 Spain
AU: Abdu, H
EM: hiruyabdu@cc.usu.edu
AF: Utah State University, Dept. Plants Soils and Biometerology, Ag Sci Building 4820, Old Main Hill , Logan, UT 84322-4820 United States
AU: Jones, S B
EM: scott.jones@usu.edu
AF: Utah State University, Dept. Plants Soils and Biometerology, Ag Sci Building 4820, Old Main Hill , Logan, UT 84322-4820 United States
AU: Chandler, D
EM: David.chandler@usu.edu
AF: Utah State University, Dept. Plants Soils and Biometerology, Ag Sci Building 4820, Old Main Hill , Logan, UT 84322-4820 United States
AU: Knight, R
EM: rknight@pangea.stanford.edu
AF: Stanford University, Dept of Geophysics, 397 Panama Mall , Stanford, CA 94305-2215 United States
AB: The development of an integrated approach to characterizing small watersheds is crucial to understanding the complex links and feedback mechanisms within them. High spatial resolution soil texture data is well correlated to soil hydraulic properties. We present preliminary work using electromagnetic induction (EMI) to map subsurface properties in small watersheds. In this work we used both the Geonics EM-38 and the Dualem EMI sensors which were integrated with a GPS receiver and handheld computer to obtain geo-referenced bulk electrical conductivity (ECa) measurements. In the vertical orientation the sensors respond to the ECa of the top meter of soil. The ECa depends on the solution EC, soil water content, clay / rock content and soil depth. Data obtained from EMI in the form of ECa maps, can provide supplementary information for assessing flow pathways and locating monitoring instrumentation without soil-specific calibration. With ECa calibration, soil texture maps can be generated. This work may be more suited to semi-arid climates where seasonal wet and dry periods can be exploited in data analysis. Current work is looking at methods of developing the best survey and calibration methodology to interpret the measured ECa response for hydrological application.
DE: 1865 Soils (0486)
DE: 1866 Soil moisture
DE: 1875 Vadose zone
DE: 1879 Watershed
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: Fall Meeting 2005