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Scott J Ikard

I am a licensed Professional Engineer with thirteen years of professional research and project engineering experience in geophysics, hydrogeology, and hydrology, with auxiliary experiences in fluvial geomorphology, civil, and geotechnical engineering.

Currently, I am a Hydrologist in the Geophysics unit of the United States Geological Survey's Texas Water Science Center, in Austin, Texas. I plan and perform applied research studies and projects that broadly encompass proposals development, geophysical and hydrologic survey planning, instrumentation, data acquisition, data processing, and publication of surface, waterborne, airborne, and borehole hydrogeophysical data. The goals of my applied work frequently include delineation and correlation of aquifer systems, geophysical assessments of local and regional surface and ground water exchange-flow patterns, quantification and uncertainty analysis of hydraulic and geophysical properties of the vadose zone, confined and unconfined aquifers throughout the world.

 

United States Geological Survey. GS1315-11 Hydrologist/Geophysicist. Austin, Texas 06/2014 – Present

  • Oversight, site selection, planning and preparation, and coordination of groundwater conservation districts, river authorities, municipal and government agencies, and public stakeholders in research-drilling and near-surface hydrogeophysical projects.
  • Planning, implementation, and oversight of waterborne and land-based geophysical field surveys using time and frequency domain electromagnetics, self-potential mapping, electric resistance tomography, seismic refraction, dilution gaging, water-level monitoring, differential global positioning systems, Calibrated surface and borehole geophysical and hydrologic instruments, and performed troubleshooting of logging instruments and data acquisition systems in the field.
  • Performed field acquisition, pre-processing, inversion, and post-processing of vertical electrical soundings and transient electromagnetic soundings, as well as surface self-potential and electrical resistivity tomography data, to map alluvial and deep confined aquifers and produce conceptual hydro-stratigraphic models for groundwater flow modeling.
  • Developed data-processing codes and algorithms for (a) automated hydro-stratigraphic interpretation and geo-electric correlations from geophysical well logs and drillers logs, (b) automated baseflow separation and recession analysis, (c) digital signal processing, (d) groundwater flow modeling, particle tracking, parameter estimation and uncertainty analysis, (e) 2D and 3D forward and inverse modeling of self-potential and DC resistivity data using finite elements, finite differences, and linear filter theory.
  • Published innovative, novel research in peer-reviewed journals and USGS reports.

Science and Products

Filter Total Items: 14

Data Used to Assess the Hydrogeologic Framework with Emphasis on the Ogallala and Edwards-Trinity Aquifers, in and Near Gaines, Terry, and Yoakum Counties, Texas, 2018

More than 11,500 well records, such as geophysical logs, drilling descriptions, and published hydrogeologic framework information, were evaluated to help characterize the framework of hydrogeologic units in and near Gaines, Terry, and Yoakum Counties, Texas. Additional geophysical data were collected to improve the spatial coverage across the study area and to reduce uncertainty with regard to hyd
By
Oklahoma-Texas Water Science Center

14.86 km Profiles of the Electric and Self-potential Fields Measured in the Lower Guadalupe River Channel, Texas Interior Gulf Coastal Plain, September 2016

This data release consists of three geophysical data sets measured in the lower Guadalupe River channel, south-central Texas, and one supplementary geophysical data set measured in a laboratory. The lower Guadalupe River is incised into the outcrop of the Carrizo-Wilcox aquifer in south-central Texas. The river and the aquifer are hydraulically connected across the outcrop, although the connectivi
By
Oklahoma-Texas Water Science Center
Filter Total Items: 16

Hydrogeophysical investigations of earthen dams – Two California case studies

Excessive groundwater seepage can be a common engineering concern with earthen dams. The application of geophysical methods, whether for characterization or for long-term monitoring, to help inform mitigation strategies is becoming a more common addition to these investigations. The U.S. Geological Survey (USGS) has completed geophysical investigations at several earthen dams in cooperation with t
Authors
Bethany L. Burton, Paul A. Bedrosian, Burke J. Minsley, Scott Ikard, Michael H. Powers
By
Geology, Geophysics, and Geochemistry Science Center

Improving our understanding of hydraulic-electrical relations: A case study of the surficial aquifer in Emirate Abu Dhabi

Transmissivity is a bulk hydraulic property that can be correlated with bulk electrical properties of an aquifer. In aquifers that are electrically-resistive relative to adjacent layers in a horizontally stratified sequence, transmissivity has been shown to correlate with bulk transverse resistance. Conversely, in aquifers that are electrically-conductive relative to adjacent layers, transmissivit
Authors
Scott Ikard, Wade H. Kress
By
Water Resources Mission Area, Oklahoma-Texas Water Science Center, International Programs

Hydrogeophysical investigations at Hidden Dam, Raymond, California

Self-potential and direct current resistivity surveys are carried out at the Hidden Dam site in Raymond, California to assess present-day seepage patterns and better understand the hydrogeologic mechanisms that likely influence seepage. Numerical modeling is utilized in conjunction with the geophysical measurements to predict variably-saturated flow through typical two-dimensional dam cross-sectio
Authors
Burke J. Minsley, Bethany L. Burton, Scott Ikard, Michael H. Powers
By
Geology, Geophysics, and Geochemistry Science Center

Geophysical investigations at Hidden Dam, Raymond, California — Flow simulations

Numerical flow modeling and analysis of observation-well data at Hidden Dam are carried out to supplement recent geophysical field investigations at the site (Minsley and others, 2010). This work also is complementary to earlier seepage-related studies at Hidden Dam documented by Cedergren (1980a, b). Known seepage areas on the northwest right abutment area of the downstream side of the dam was do
Authors
Burke J. Minsley, Scott Ikard
By
Geology, Geophysics, and Geochemistry Science Center

Non-USGS Publications**

Ikard, S. J., A. Revil, A. Jardani, W. F. Woodruff, M. Parekh, and M. Mooney (2012), Saline pulse test monitoring with the self-potential method to nonintrusively determine the velocity of the pore water in leaking areas of earth dams and embankments, Water Resour. Res., 48, W04201, doi:10.1029/2010WR010247.
Ikard, S. J., Gooseff, M. N., Barrett, J. E. and Takacs‐Vesbach, C. (2009), Thermal characterisation of active layer across a soil moisture gradient in the McMurdo Dry Valleys, Antarctica. Permafrost Periglac. Process., 20: 27-39. doi:10.1002/ppp.634

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Science and Products