Abstract
Levee characterization requires many miles of ground to be surveyed. Remote sensing methods, particularly those capable of installation on an aircraft, are capable of quickly surveying large areas. The helicopter frequency domain electromagnetic technique (HEM) involves towing an electromagnetic transmitter and receiver that measure signals proportional to the electrical conductivity of the ground. Information about the electrical conductivity of the ground can be used to make inferences about the distribution of soils or rocks in the subsurface. HEM data can be interpreted by correlating the apparent conductivity to soil or rock type, as well as for looking for lateral and depth extent of anomalous zones. HEM data provide depth information by performing measurements at different frequencies. Here, we provide a brief review of the frequency domain method, highlighting the transformation of HEM data to apparent resistivity, which is critical for interpretation. We then discuss two case histories using an HEM system for levee characterization and hazard detection. With clay being the primary building material for the levees, the minimum layer thickness that can be accurately resolved with an upper frequency of 140 kHz is about 1 m. The HEM data are particularly useful at detecting anomalous zones for follow up investigation. These zones were caused by underground channels (which provide pathways for water flow) and in one case by significant cracking of a levee. The examples provided here highlight the utility of HEM surveying for levee characterization.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Amine, D., Hodges, G. H., Selvamohan, S., and Marlow, D. Correlating Helicopter EM and Borings for Levee Evaluation Studies in California. Symposium on the Application of Geophysics to Engineering and Environmental Problems 2009: pp. 126–134.
Dunbar, J.B., Llopis, J.L., Sills, G.L., Smith, E.W., Miller, R.D, Ivanov, J., and Corwing, R.F. Condition Assessment of Levees, U.S. Section of the International Boundary and Water Commission. Report 5 Flood Simulation Study of Retamal Levee, Lower Rio Grande Valley, Texas, Using Seismic and Electrical Geophysical Models. Army Corps of Engineers, 2005.
Fraser, D. C., Resistivity mapping with an airborne multicoil electromagnetic system, Geophysics, 43, 1, 1978.
Fountain, D., Airborne electromagnetic systems—50 years of development. Exploration Geophysics, 29, 1–11, 1998.
Frischknecht, F.C., 1967, Fields about an oscillating magnetic dipole over a two-layer earth, and application to ground and airborne electromagnetic surveys: Quarterly Colorado School of Mines, 62, 1–326
Grant, F.S. and West, G.S., Interpretation Theory in Applied Geophysics, McGraw-Hill, 1984.
Huang, H. and Fraser, D.C., The differential parameter method of multifrequency airborne resistivity mapping. Geophysics, 61:1, 100–109, 1996.
Reid, J.E., Worby, A.P., Vrbancich, J. and A.I.S. Munro. Shipborne electromagnetic measurements of Antarctic sea‐ice thickness. Geophysics, 68:5, 1537–1546, 2003.
Palacky, G.J., The airborne electromagnetic method as a tool of geological mapping, Geophysical Prospecting, 29, 1981.
Palacky, G. J., Resistivity Characteristics of Geologic Targets. Electromagnetic Methods in Applied Geophysics, Society of Exploration Geophysics, 1988.
Sacramento Area Flood Control Agency, http://www.safca.org/Images/Maps/SacramentoRiverFloodControlSystem.pdf, 2018.
Siemon, B. “Electromagnetic methods—frequency domain”, in Groundwater geophysics—a tool for hydrogeology, ed. R. Kirsch, Springer-Verlag, 2006.
Sorensen, J. C., and Chowdhury, K. 2010. Levee Subsurface Investigation Using Geophysics, Geomorphology, and Conventional Investigative Method. Proceedings of 30th Annual USSD Conference, Sacramento, California, April 12–16, 2010.
Spies B.R. 1989. Depth of investigation in electromagnetic sounding methods. Geophysics 54, 872–888.
Stanley H. Ward, (1967), 2. Part A. Electromagnetic Theory for Geophysical Applications, General Series : 13–196
Ward, S.H. and Hohmann, G.W. 1988, Electromagnetic theory for Geophysical applications, in Nabighian, M. N. Ed., Electromagnetic methods in applied geophysics, Vol. 1: Society of Exploration Geophysics, 131–312.
West, G.F and Macnae, J. Physics of the electromagnetic induction exploration method, in Electromagnetic methods in applied geophysics, Ed.M Nabighian, Society of Exploration Geophysicists, 1991.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Switzerland AG
About this chapter
Cite this chapter
Smiarowski, A., Hodges, G., Dunbar, J. (2019). Application of the Helicopter Frequency Domain Electromagnetic Method for Levee Characterization. In: Lorenzo, J., Doll, W. (eds) Levees and Dams. Springer, Cham. https://doi.org/10.1007/978-3-030-27367-5_6
Download citation
DOI: https://doi.org/10.1007/978-3-030-27367-5_6
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-030-27366-8
Online ISBN: 978-3-030-27367-5
eBook Packages: Physics and AstronomyPhysics and Astronomy (R0)