The Boise Hydrogeophysical Research Site (BHRS) is an in situ field laboratory (research wellfield) that is being developed by CGISS in a shallow, coarse (cobble-and-sand), alluvial aquifer. Our goal is to develop cost-effective, non-invasive methods for quantitatively characterizing the distribution of permeability in heterogeneous aquifers using hydrologic and geophysical techniques. Permeability is the most significant aquifer parameter for quantitatively describing or modeling groundwater flow and contaminant transport, and for designing remediation systems. The BHRS is located on a gravel bar adjacent to the Boise River about 15 km southeast of downtown Boise. Eighteen wells were emplaced at the site in 1997 and 1998. The stratigraphy consists of coarse, cobble-and-sand, braided-stream fluvial deposits that overlie a clay layer at about 20 m depth. The design of the wells and the wellfield provides for a wide range of surface, single-well, cross-hole, multiwell and multilevel hydrologic, geophysical, well log and combined hydrologic-geophysical tests.

# Boise Hydrogeo-physical Research Site (BHRS)

### Geophysical Methods

At the BHRS our intention is to thoroughly characterize the wellfield as a control volume with “known” 3-D distributions of sedimentary facies, geophysical parameters, and hydrologic parameters. Then responses from geophysical methods, alone and together, can be correlated against known parameter distributions to develop techniques for mapping the 3-D distribution of permeability with non-invasive geophysical methods. Initial efforts will concentrate on three generally accessible geophysical methods: seismic, ground penetrating radar (GPR) and transient or time-domain electromagnetics (TEM). Also a variety of borehole geophysical logs are being run in all wells.

Issues such as resolution, depth of penetration, and the ability to measure or image desired parameters will determine the usefulness of different geophysical methods. For example, GPR provides high resolution subsurface reflection images, but does not penetrate to the deeper parts of the aquifer at the BHRS. TEM, on the other hand, measures the 1-D electrical resistivity distribution with depth throughout the full aquifer thickness, but with less vertical resolution. Additional important data sets from the BHRS are the core analyses and geophysical well logs from the 18 wells at the site. We are using these data to verify and calibrate our geophysical interpretations. The many geophysical methods and acquisition geometries, combined with the well control, will provide an outstanding data set to characterize the heterogeneity of the alluvial aquifer and to develop techniques for mapping permeability with non-invasive geophysical methods.

### Crosshole GPR Tomography Results

We are acquiring lots of crosshole tomographic data at the BHRS. To show the tomography data, we have put a movie together (to the left) showing an entire tomography data set. Each panel of the movie shows the recorded wave as the receiver is lowered at 0.25 m intervals down the well. The vertical axis records the depth of the receiver in the well from 1 to 18 meters. The horizontal axis records the time from 0 to 200 ns. Note how the continuity of the signal changes as the receiver passes boundaries beneath the surface.

A variety of acquisition geometries are available with borehole experiments to determine the velocity structure in the subsurface. Level runs (figure to the left), where the source and receiver are lowered down the borehole at the same depths, provide quick, one-dimensional information about the horizontal velocity. Vertical profiles, like VRPs and VSPs, provide information about the vertical interval velocities. Single hole reflection studies are used primarily in consolidated sediments or hard rock to detect fractures in the subsurface. Tomography (figure to the right) provides a detailed, two- or three-dimensional image of the subsurface, but is very time consuming to acquire and process. At the BHRS, we have acquired VRPs, level runs, and tomography data sets, The level runs provide quality control and help calibrate origin times in the tomography data. Velocities obtained from VRPs can help constrain tomographic inversions. Tomographic data, although expensive to acquire, provides detailed information about both vertical and lateral velocity changes in the subsurface.

### Tomography and Inversion

Crosshole tomography provides a method to determine the velocity structure between two wells. CGISS uses a two-dimensional, finite-difference approximation to the eikonal equation to generate ray paths through the model. In the inversion, we use a weighted, damped, least squares approach to solve the ill-posed, ill-conditioned problem. We are investigating different ways to incorporate constraints on the problem to compute a more accurate subsurface velocity distribution. The most common method to constrain the solution invokes Occam’s razor. Occam’s razor states that in the absence of other information, use the simplest solution. For tomographic inversion, the procedure imposes the simplest structure on the model that fits the data. Thus smoothness constraints are used when inverting the data. Another approach that is gaining acceptance is Bayesian inversion. In the Bayesian case, the inversion routine incorporates a priori information to constrain the model. Bayesian inversion can update the inverted model as more information about the subsurface is discovered.

Formal inversion methods enable an error analysis of the results. Unfortunately, most routines use a method that solves for the model directly, without computing the inverse solution. We are modifying inversion algorithms to compute or approximate the matrix inverse, so that we can assess the resolution and uncertainty in our models. Error analysis is a crucial aspect of inversion that warrants further research into both efficient error computation and interpretaion of error distribution in the modeled space.

### Results and Analysis

The figure on the left (click to enlarge) is the tomogram for well pair C6 and C5 at the BHRS. The receiver is in well C6 (stars) and the transmitter is in C5 (circles). The wells are deviated from the vertical. I account for the deviation in the tomographic inversion. The color scale corresponds to the subsurface velocities. Above the water table, the velocities are off scale so that the variation in the saturated zone is easier to see. The solid curves to the left and right of the wells are the neutron-derived porosity logs. The plot to the right is the distribution of the travel time residuals for this inversion. The source depths are plotted vertically and the receiver depths are plotted horizontally. The largest residuals are near the water table, where the forward routine has difficulty accurately modeling the wave propagation.

I have plotted the diagonal elements of the resolution (left) and the covariance (right) for the tomogram. Resolution measures how well the model locates the parameter. The resolution plot is very similar to the ray density plot. Cells with high resolution values correlate with cells with high ray density. This correspondence justifies using the ray density as a qualitative approximation for the model resolution.

Covariance measures the uncertainty in the inverted parameter value. As expected, the covariance values are correlated with the resolution values. Large covariance values indicate highly resolved cells. As more rays traverse the cell, we are more assured of its position. However, more variance is associated with the increased number of rays, so the covariance increases. For those cells with only a few ray crossings, the variance will be small, but the resolution will be large and the value poorly constrained.

We are also collaborating with researchers from Lawrence Berkeley Laboratories (Ernie Majer, John Peterson, Ken Williams, and Tom Daley) to develop crosshole radar and seismic tomography methods for imaging the zones between wells and estimating dielectric and seismic properties at the site. These material property distributions will then be compared to the porosity and permeability distributions derived from hydrologic well tests. Here are some examples of preliminary radar tomographic inversions performed by LBL for three wells in a triangular pattern.

For more information about this research, and preliminary results using the LBL high-frequency piezoelectric borehole seismic source at the BHRS, see the SAGEEP’99 paper by Peterson et al.

### Acknowledgments

Development of the BHRS has been supported by U.S. Army Research Office grant DAAH04-96-1-0318 and U.S. EPA grants X-970085-01-0 and X-96004601-0 and -1. Cooperative arrangements with the Idaho Transportation Department, the U. S. Bureau of Reclamation, and Ada County allow development and use of the BHRS. Grants from the M. J. Murdock Charitable Trust and the U.S. Army Research Office (grant DAAD19-00-1-0105) have provided major support for instrumentation used in research at the BHRS.

### Publications

**PEER-REVIEWED PAPERS, by year can be found below.**

Mi, B., Xia, J., Bradford, J.H., and Shen, C., 2020, Estimating near-surface shear-wave-velocity structures via multichannel analysis of Rayleigh and Love waves: An experiment at the Boise Hydrogeophysical Research Site: Surveys in Geophysics, Online Version of Record before inclusion in an issue: https://doi.org/10.1007/

Cardiff, M., Zhou, Y., Barrash, W., and Kitanidis, P.K., 2019, Aquifer imaging with oscillatory hydraulic tomography: Application at the field scale: Groundwater, Online Version of Record before inclusion in an issue: https://doi.org/10.1111/gwat.

Pirot, G., Linde, N., Mariethoz, G., and Bradford, J.H., 2017, Probabilistic inversion with graph cuts: Application to the Boise Hydrogeophysical Research Site: Water Resources research, v. 53, no. 2, p. 1231-1250.

Binley, A., Keery, J., Slater, L., Barrash, W., and Cardiff, M., 2016, The hydrogeologic information in cross-borehole complex conductivity data from an unconsolidated conglomeratic sedimentary aquifer: Geophysics, v. 81, no. 6, p. E409-E421, doi:10.1190/GEO2015-0608.1.

Hochstetler,.D.L., Barrash, W., Leven, C., Cardiff, M., Chidichimo, F., and Kitanidis, P.K., 2016, Hydraulic tomography: Continuity and discontinuity of high-K and low-K zones: Groundwater, v. 54, no. 2, p. 171-185 doi: 10.1111/gwat.12344.

Cardiff, M. and Barrash, W., 2015, Analytical and semi-analytical tools for the design of oscillatory pumping tests: Groundwater, v. 53, no. 6, 896-907, doi: 10.1111/gwat.12308.

Rabinovich, A., Barrash, W., Cardiff, M., Hochstetler, D.L., Bakhos, T., Dagan, G., and Kitanidis, P.K., 2015, Frequency dependent hydraulic properties estimated from oscillatory pumping tests in an unconfined aquifer: Journal of Hydrology, v. 531, p. 2-16, doi: 10.1016/j.jhydrol.2015.08.021.

Bakhos, T., Cardiff, M., Barrash, W., and Kitanidis, P.K., 2014, Data processing for oscillatory pumping tests: Journal of Hydrology, v.511, p. 310-319, doi: 10/1016/j.jhydrol.2014.01.007.

Dagan, G. and Rabinovich, A., 2014,Oscillatory pumping wells in phreatic, compressible, and homogeneous aquifers: Water Resources Research, v. 50, p. 7058-7066, doi:10.1002/2014WR015454.

Slater, L., Barrash, W., Montrey, J., and Binley, A., 2014, Electrical-hydraulic relationships observed for unconsolidated sediments in the presence of a cobble framework: Water Resources Research, v. 50, doi:10.1002/2013WR014631.

Thoma, M.J., Barrash, W., Cardiff, M., Bradford, J., and Mead, J., 2014, Estimating unsaturated hydraulic functions for coarse sediment from a field-scale infiltration experiment: Vadose Zone Journal, v. 13, no. 3, doi:10.2136/vzj2013.05.0096.

Yang, X., Klotzsche. A., Meles, G., Vereecken, H., and van der Kruk, J., 2013,

Improvements in crosshole GPR full-waveform inversion and application on data measured at the Boise Hydrogeophysics Research Site: Journal of Applied Geophysics, v. 99, p. 114-124.

Cardiff, M., Barrash, W., and Kitanidis, P.K., 2013, Hydraulic conductivity imaging from 3D transient hydraulic tomography at several pumping/observation densities: Water Resources Research, v. 49, no. 11, p. 7311-7326, doi: 10.1002/wcrc.20519.

Cardiff, M., Bakhos, T., Kitanidis, P.K., and Barrash, W., 2013, Aquifer heterogeneity characterization with oscillatory pumping: sensitivity analysis and imaging potential: Water Resources Research, v. 49, no. 9, p. 5395-5410, doi: 10.1002/wcrc.20356.

Johnson, B., Malama, B., Barrash, W., and Flores, A., 2013, Recognizing and modeling variable drawdown due to evapotranspiration in a semi-arid riparian zone considering local differences in vegetation and distance from a river source: Water Resources Research, v. 49, no.2, p. 1030-1039, doi: 10.1002/wrcr.20122.

Belina, F.A., Irving, J., Ernst, J.R., and Holliger K., 2012, Waveform inversion of crosshole georadar data: Influence of source wavelet variability and the suitability of a single wavelet assumption: IEEE Transactions on Geoscience and Remote Sensing, v. 50, no. 11, p. 4610-46725, doi: 10.1109/TGRS.2012.2194154.

Cardiff, M., Barrash, W., and Kitanidis, P., 2012, A field proof-of-concept of aquifer imaging using 3D transient hydraulic tomography with modular, temporarily-emplaced equipment: Water Resources Research, v. 48, W05531, doi: 10.1029/2011WR011704.

Dafflon, B. and Barrash, W., 2012, Benefits of using GPR velocity tomograms in conjunction with porosity log data for 3-D stochastic estimation of porosity distribution at the Boise Hydrogeophysical Research Site: Water Resources Research, v. 48, W05553, doi: 10.1029/2011WR010916.

Cardiff, M. and Barrash, W., 2011, 3D transient hydraulic tomography in unconfined aquifers with fast drainage response: Water Resources Research, v. 47, W12518, doi: 10.1029/2010WR010367.

Cardiff, M., Barrash, W., Thoma, M., and Malama, B., 2011, Information content of slug tests for estimating hydraulic properties in realistic, high-conductivity aquifer scenarios: Journal of Hydrology, v. 403, no. 1-2, p. 66-82, doi: 10.1016/j.jhydrol.2011.03.044.

Dafflon, B., Barrash, W., Cardiff, M., and Johnson, T.C., 2011, Hydrological parameter estimations from a conservative tracer test with variable-density effects at the Boise Hydrogeophysical Research Site: Water Resources Research, v. 47, no. 12, W12513, doi: 10.1029/2011WR010789.

Dafflon, B., Irving, J., and Barrash, W., 2011, Inversion of multiple intersecting high resolution crosshole GPR profiles for hydrological characterization at the Boise Hydrogeophysical Research Site: Journal of Applied Geophysics, v. 73, p. 305-314.

Malama, B., 2011, Alternative linearization of water table kinematic condition for unconfined aquifer pumping test modeling and its implications for specific yield estimates: Journal of Hydrology, v. 399, p. 141-147.

Malama, B., Khulman, K., Barrash, W., Cardiff, M., and Thoma, M., 2011, Modeling slug tests in unconfined aquifers taking into account water table kinematics, wellbore skin and inertial effects: Journal of Hydrology, v. 408, p. 113-126, doi: 10.1016/j.jhydrol.2011.07.028.

Mikesell, D. and van Wijk, K., 2011, Seismic refraction interferometry with a semblance analysis on the cross-correlation gather: Geophysics, v. 76, no. 5, p. SA77–SA82, doi: 10.1190/GEO2011-0079.1.

Straface, S., Chidichimo, F., Rizzo, E., Riva, M., Barrash, W., Revil, A., Cardiff, M., and Guadgnini, A., 2011, Joint inversion of steady-state hydrologic and self-potential data for 3D hydraulic conductivity distribution at the Boise Hydrogeophysical Research Site: Journal of Hydrology, v. 407, no. 1-4, p. 115-128, doi: 10.1016/j.jhydrol.2011.07.013.

Clemo, T., 2010, Coupled borehole-aquifer simulation: Ground Water, v. 48, no. 1, p. 68-78, doi: 10.1111/j.1745-6584.2009.00597.x.

Gokturkler, G. and Balkaya, C., 2010, Traveltime tomography of crosshole radar data without ray tracing: Journal of Applied Geophysics, v. 72, p. 213-224.

Hinz, E.A. and Bradford, J.H., 2010, Ground-penetrating-radar reflection attenuation tomography with an adaptive mesh: Geophysics, v. 75, no. 4, p. WA251-WA261.

Malama, B. and Johnson, B., 2010, Analytical modeling of a saturated zone head response to evapotranspiration and river-stage fluctuations: Journal of Hydrology, v. 382, p. 1-9, doi:10.1016/j.jhydrol.2009.12.010.

Nichols, J., Mikesell, D., and VanWijk, K., 2010, Application of the virtual refraction to near-surface characterization at the Boise Hydrogeophysical Research Site: Geophysical Prospecting, v. 58, p. 1011-1021.

Bradford, J.H., Clement, W.P., and Barrash, W., 2009, Estimating porosity with ground-penetrating radar reflection tomography: A controlled 3D experiment at the Boise Hydrogeophysical Research Site: Water Resources Research, 45, W00D26, doi:10.1029/2008WR006960.

Cardiff, M., Barrash, W., Kitanidis, P., Malama, B., Revil, A., Straface, S., and Rizzo, E., 2009, A potential-based inversion of unconfined steady-state hydrologic tomography: Ground Water, vol. 47, no. 2, p. 259-270, doi: 10.1111/j.1745-6584.2008.00541.x.

Clemo, T., Barrash, W., Reboulet, E.C., Johnson, T.C., and Leven, C., 2009, The influence of wellbore inflow on electromagnetic borehole flowmeter measurements: Ground Water, v. 47, no. 4, p. 515-525, doi: 10.1111/j.1745-6584.2008.00559.x.

Dafflon, B., Irving, J., and Holliger, K., 2009, Simulated-annealing-based conditional simulation for the local-scale characterization of heterogeneous aquifers: Journal of Applied Geophysics, v. 68, no. 1, p. 60-70, doi:10.1016/j.jappgeo.2008.09.010.

Dafflon, B., Irving, J., and Holliger, K., 2009, Quantitative integration of high-resolution hydrogeophysical data: A novel approach to Monte-Carlo-type conditional stochastic simulations and implications for hydrological predictions: Journal of Earth Science, v. 20, no. 3, p. 580-591, doi: 10.1007/s12583-009-0048-6.

Fienen, M.N., Hunt, R., Krabbenhoft, D., and Clemo, T., 2009, Obtaining parsimonious hydraulic conductivity fields using head and transport observations: A Bayesian geostatistical parameter estimation approach:Water Resources Research, v. 45, W08405, doi: 10.1029/2008WR007431.

Hu, B.X., Meerschaert, M.M., Barrash, W., Hyndman, D.W., He, C., Li, X., and Guo, L., 2009, Examining the influence of heterogeneous porosity fields on conservative solute transport: Journal of Contaminant Hydrology, v. 108, p. 77-88, doi:10.1016/j.jconhyd.2009.06.001.

Jardani, A., Revil, A., Barrash, W., Crespy, A., Rizzo, E., Straface, S., Cardiff, M., Malama, B., Miller, C., and Johnson, T., 2009, Reconstruction of the water table from self-potential data during dipole pumping/injection test experiments: Ground Water, vol. 47, no. 2, p. 213-227, doi: 10.1111/j.1745-6584.2008.00513.x.

Malama, B. and Barrash, W., 2009, Flow in the neighborhood of a confined aquifer observation well: Journal of Hydrology, v. 364, p. 107-114, doi:10.1016/j.jhydrol.2008.10.014.

Malama, B., Revil, A. and Kuhlman, K. L., 2009, A semi-analytical solution for transient streaming potentials associated with confined aquifer pumping tests, Geophysical Journal International, v. 176, p. 1007-1016, doi:10.1111/j.1365-246X.2008.04014.x.

Mwenifumbo, C.J., Barrash, W., and Knoll, M.D., 2009, Capacitive conductivity logging and electrical stratigraphy in a high-resistivity aquifer, Boise Hydrogeophysical Research Site: Geophysics, v. 74, no. 3, p. E125-E133, doi:10.1190/1.3106760.

Oldenborger, G.A. and Routh, P.S., 2009, The point-spread function measure of resolution for the 3D electrical resistivity experiment: Geophysical Journal International, v. 176, p. 405-414.

Buursink, M.L., Johnson, T.C., Routh, P.S., and Knoll, M.D., 2008, Cross-hole radar propagation velocity tomography using Fresnel volume sensitivities: Geophysical Journal International, v. 172, no.1, p. 1-17, doi:10.1111/j.1365-246X.2007.03589.x

Fienen, M. N., T. M. Clemo, and P. K. Kitanidis, 2008, An interactive Bayesian geostatistical inverse protocol for hydraulic tomography: Water Resources Research, v. 44, W00B01, doi:10.1029/2007WR006730.

Malama, B., Kuhlman, K.L., and Barrash, W., 2008, Semi-analytical solution for flow in a leaky unconfined aquifer toward a partially penetrating pumping well: Journal of Hydrology, v. 356, p. 234-244, doi:10.1016/j.jhydrol.2008.03.029.

Yeh, T.-C. J., Lee, C.-H., Hsu, K.-C., Illman, W.A., Barrash, W., Cai, X., Daniels, J., Sudicky, E., Wan, L., Li, G., and Winter, C.L., 2008, A view towards the future of subsurface characterization: CAT scanning groundwater basins: Water Resources Research, v. 44, W03301, doi:10.1029/2007WR006375.

Ernst, J.R., Green, A.G., Maurer, H., and Holliger, K., 2007, Application of a new 2D time-domain full-waveform inversion scheme to crosshole radar data: Geophysics, v. 72, no. 5, p. J53-J64.

Irving, J.D., Knoll, M.D., and Knight, R.J., 2007, Improving crosshole radar velocity tomograms: A new approach to incorporating high-angle traveltime data: Geophysics, v. 72, no. 4, p. J31-J41.

Jardani, A., Revil, A., Boleve, A., Crespy, A., Dupont, J.-P., Barrash, W., and Malama, B., 2007, Tomography of the Darcy velocity from self-potential measurements: Geophysical Research Letters, v. 34, L24403, doi:10.1029/2007GL031907.

Johnson, T.C., Routh, P.S., Barrash, W., and Knoll, M., 2007, A field comparison of Fresnel zone and ray-based GPR attenuation-difference tomography for time-lapse imaging of electrically anomalous tracer or contaminant plumes: Geophysics, v. 72, no. 2, p. G21-G29.

Johnson, T.C., Routh, P.S., Clemo, T., Barrash, W., and Clement, W., 2007, Incorporating geostatistical constraints in nonlinear inverse problems: Water Resources Research, v. 43, W10422, doi:10.1029/2006WR005185.

Malama, B., Kuhlman, K.L., and Barrash, W., 2007, Semi-analytical solution for flow in leaky unconfined aquifer-aquitard systems: Journal of Hydrology, v.346, p. 59-68, doi:10.1016/j.jhydrol.2007.08.018.

Miller, C.R., and Routh, P.S., 2007, Resolution analysis of geophysical images: Comparison between point spread function and region of data influence measures: Geophysical Prospecting, 55, 1-18, doi:10.1111/j.1365-2478.2007.00640.x.

Oldenborger, G.A., Knoll, M.D., Routh, P.S., and LaBrecque, D.J., 2007, iTime-lapse ERT monitoring of an injection/withdrawal experiment in a shallow unconfined aquifer, Geophysics, 72(4), F177â€“F187.

Oldenborger, G.A., Routh, P.S., and Knoll, M.D., 2007, Model reliability for 3D electrical resistivity tomography: Application of the volume of investigation index to a time-lapse monitoring experiment, Geophysics, 72(4), F167â€“F175.

Barrash, W., Clemo, T., Fox, J.J., and Johnson, T.C., 2006, Field, laboratory, and modeling investigation of the skin effect at wells with slotted casing, Boise Hydrogeophysical Research Site: Journal of Hydrology, v. 326, no.1-4, p. 181-198 doi:10.1016/j.jhydro/2005.10.029.

Clement, W.P., 2006, Issues during the Inversion of crosshole radar data: Can we have confidence in the outcome?” Journal of Engineering and Environmental Geophysics, v. 11, p. 269-287.

Clement, W.P. and Barrash, W., 2006, Crosshole radar tomography in an alluvial aquifer near Boise, Idaho (PDF): Journal of Environmental and Engineering Geophysics, v. 11, no. 3, p. 171-184.

Clement, W.P., Barrash, W., and Knoll, M.D., 2006, Reflectivity modeling of ground penetrating radar: Geophysics, v. 71, p. K59-K66.

Clement, W.P., and Knoll, M.D., 2006, Traveltime inversion of vertical radar profiles, Geophysics, v. 71, p. K67-K76.

Clemo, T. 2006, Flow in perforated pipes: A comparison of models and experiments, SPE Production and Facilities, v. 21, p. 302-311.

Moret, G.J.M., Knoll, M.D., Barrash, W., and Clement, W.P., 2006, Investigating the stratigraphy of an alluvial aquifer using crosswell seismic traveltime tomography: Geophysics, v. 71, p. B63-B73.

Oldenborger, G.A., and Routh, P.S., 2006, Theoretical development of the scattering decomposition for the 3D resistivity experiment, Geophysical Prospecting, v. 54, p. 463-473.

Barrash, W. and Clemo, T., 2005, Correction to ‘‘Hierarchical geostatistics and multifacies systems: Boise Hydrogeophysical Research Site, Boise, Idaho:’’ Water Resources Research, v. 41, W11702, doi:10.1029/2005WR004616.

Clemo, T., 2005, Improved water-table dynamics in MODFLOW: Ground Water, v. 42, no. 3, p. 270-273.

Johnson, T.C., Routh, P.S., and Knoll, M.D., 2005, Fresnel volume georadar attenuation-difference tomography. Geophysical Journal International, v. 162, p. 9-24.

Oldenborger, G.A., Routh, P.S., and Knoll, M.D., 2005, Sensitivity of electrical resistivity tomography data to electrode position errors: Geophysical J. International, v. 163, p. 1-9.

Tronicke, J., and Knoll, M.D., 2005, Vertical radar profiling: influence of survey geometry on first-arrival traveltimes and amplitudes: J. Applied Geophysics, v. 57, p. 179-191.

Barrash, W. and Reboulet, E.C., 2004, Significance of porosity for stratigraphy and textural composition in subsurface coarse fluvial deposits, Boise Hydrogeophysical Research Site: Geological Society of America Bulletin, v. 116, no. 9/10, p. 1059-1073, doi:10.1130/B25370.1.

Moret, G.J.M., Clement, W.P., Knoll, M.D., and Barrash, W., 2004, VSP traveltime inversion: Near-surface issues: Geophysics, v. 69, no. 2, 345-351.

Oldenborger, G.A., Knoll, M.D., and Barrash, W., 2004, Effects of signal processing and antenna frequency on the geostatistical structure of ground-penetrating radar data: Journal of Environmental & Engineering Geophysics v. 9, no. 4, p. 201-212.

Tronicke, J., Holliger, K., Barrash, W., and Knoll, M.D., 2004, Multivariate analysis of crosshole georadar velocity and attenuation tomograms for aquifer zonation: Water Resources Research v. 40, no. 1, W01519, 10.1029/2003WR002031, 2004.

Barrash, W. and Clemo, T., 2002, Hierarchical geostatistics and multifacies systems: Boise Hydrogeophysical Research Site, Boise, Idaho: Water Resources Research, v. 38, no. 10, 1196, 10.1029/2002WR001436, 2002.

**CONFERENCE PAPERS, by year:**

Bradford, J., 2006, Frequency dependent attenuation of ground-penetrating radar data: SAGEEP2006, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, Seattle, WA

Clement, W.P. and Barrash, W., 2006, Crosshole radar tomography in an alluvial aquifer near Boise, Idaho (PDF): SAGEEP2006, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, Seattle, WA.

Miller, C.R. and Routh, P.S., 2006, Resolution analysis of geophysical images: Comparison of point spread function and region of data influence measures: SEG annual meeting in New Orleans, p. 1-4.

Muffels, C., Tonkin, M., Zhang, H., Anderson, M., and Clemo, T., 2006, Application of LSQR to calibration of a MODFLOW model: A synthetic study, MODFLOW and more 2006: Managing Ground-Water Systems – Conf. Proc., Poeter, Hill & Zheng (eds), International Ground Water Modeling Center, Golden CO, 283-287.

Routh, P.S. and Miller, C.R., 2006, Image interpretation using appraisal analysis: SAGEEP2006, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, Seattle, WA.

Routh, P. S., Oldenborger, G. A., and Oldenburg, D. W., 2005, Optimal survey design using the point spread function measure of resolution, SEG expanded abstracts, p. 1033-1036.

Johnson, T. C., Routh, P. S., Knoll, M. D., and Barrash, W., 2005, Attenuation difference tomography of cross-well radar data using Fresnel theory, SEG expanded abstracts, p. 1069-1072.

Barrash, W., Knoll, M.D., Hyndman, D.W., Clemo, T., and Hausrath, E.M., 2003, Tracer/Time-Lapse Radar Imaging Test at the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP03, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2003, San Antonio, TX, p. 163-174.

Clemo, T., 2003, Improved water table dynamics in block-centered finite-difference flow models, Proc. of MODFLOW and more 2003 understanding through modeling, International Ground Water Modeling Center, Golden CO, p. 47-50.

Clemo, T. and Barrash, W., 2003, Inversion of borehole flowmeter measurements considering well screen clogging and skin, Proc. of MODFLOW and more 2003 understanding through modeling, International Ground Water Modeling Center, Golden CO, p. 99-103.

Clemo, T., Michaels, P., and Lehman, R. M., 2003, Transmissivity resolution obtained from the inversion of transient and pseudo-steady drawdown measurements, Proc. of MODFLOW and more 2003 understanding through modeling, International Ground Water Modeling Center, Golden CO, p. 629-633.

Goldstein, S.E., Knoll, M.D., Barrash, W., and Clement, W.P., 2003, Borehole radar attenuation tomography during the Tracer/Time-Lapse Test at the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP03, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2003, San Antonio, TX, p. 147-162

Moret, G.J.M. and Knoll, M.D., 2003, The value of borehole-to-surface information in near-surface crosswell seismic tomography: Proceedings of SAGEEP03, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 6-10, 2003, San Antonio, TX, p. 131-141.

Tonkin, M., Clemo, T., and Doherty, J., 2003, Computationally efficient regularized inversion for highly parameterized MODFLOW models: Proc. of MODFLOW and more 2003 understanding through modeling, International Ground Water Modeling Center, Golden, CO, p. 595-599.

Clement, W. P. and M. D. Knoll, 2001, A comparison of vertical and horizontal GPR velocity estimates in alluvial sediments: Proceedings of SAGEEP2001, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 4-7, 2001, Denver, CO, GP 2-4.

Liberty, L., Wood, S. and Barrash, W., 2001, Seismic reflection imaging of hydrostratigraphic facies in Boise: 71st Ann. Mtg, Society of Exploration Geophysicists, p. 1393â€‘1396.

Barrash, W. and Clemo, T., 2000, Hierarchical geostatistics of porosity derived from neutron logs at the Boise Hydrogeophysical Research Site, Boise, Idaho: Proceedings of TraM’2000, Liege, Belgium, May 23-26, 2000, IAHS Publ. no. 262, p. 333-338.

Clement, W. P. and M. D. Knoll, 2000, Tomographic inversion of crosshole radar data: Confidence in results: Proceedings of SAGEEP2000, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, February 20-24, 2000, Arlington, VA, p. 553-562.

Liberty, L. M., W. P. Clement, and M. D. Knoll, 2000, Crosswell seismic reflection imaging of a shallow cobble-and-sand aquifer: An example from the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP2000, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, February 20-24, 2000, Arlington, VA, p. 545-552.

Barrash, W., T. Clemo, and M.D. Knoll, 1999, Boise Hydrogeophysical Research Site (BHRS): Objectives, design, initial geostatistical results: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 389-398.

Clement, W.P., L.M. Liberty, and M.D. Knoll, 1999, Reverse VSPs and crosshole seismic tomography while coring: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 713-722.

Clement, W.P., M.D. Knoll, L.M. Liberty, P.R. Donaldson, P. Michaels, W. Barrash, and J.R. Pelton, 1999, Geophysical surveys across the Boise Hydrogeophysical Research Site to determine geophysical parameters of a shallow, alluvial aquifer: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 399-408.

Knoll, M.D., and W.P. Clement, 1999, Vertical radar profiling to determine dielectric constant, water content and porosity values at well locations: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 821-830.

Liberty, L.M., W.P. Clement, and M.D. Knoll, 1999, Surface and borehole seismic characterization of the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 723-732.

Peretti, W.R., M.D. Knoll, W.P. Clement, and W. Barrash, 1999, 3-D GPR imaging of complex fluvial stratigraphy at the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 555-564.

Peterson, J.E., Jr., E.L. Majer, and M.D. Knoll, 1999, Hydrogeological property estimation using tomographic data at the Boise Hydrogeophysical Research Site: Proceedings of SAGEEP99, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 14-18, 1999, Oakland, CA, p. 629-638.

Barrash, W. and Knoll, M.D., 1998, Design of research wellfield for calibrating geophysical methods against hydrologic parameter: Proceedings, Conference on Hazardous Waste Research, Snowbird, UT, May 19-21, 1998, Great Plains/Rocky Mountains Hazardous Substance Research Center, Kansas State University, p. 296-318.

Barrash, W., P. Donaldson, K. Huang, M. Knoll, P. Michaels, J. and Pelton, 1997, Toward Joint Inversion of Hydrologic and Geophysical Data for Permeability Distribution in an Alluvial Aquifer. Selected Research in Environmental Quality Fiscal Year 1996, Proceedings Joint USAF/Army Contractor/Grantee Meeting, January 14-17, Panama City, FL, p. 9-17.

**THESES AND DISSERTATIONS, by year:**

Thoma, M., 2014, Estimating unsaturated flow properties in coarse conglomeratic sediment: PhD Dissertation, Boise State University, 133 p.

Mikesell, D., 2012, Subsurface characterization using head-wave artifacts in seismic interferometry: PhD Dissertation, Boise State University, 121 p.

West, M.T.N., 2012, Seismoelectric experiments in a natural laboratory: Comparisons of theoretical and measured transfer functions for co-seismic arrivals: M.S. Thesis, University of New Brunswick, Fredericton, Canada.

Belina, F., 2011, Source wavelet estimation for waveform inversion of crosshole georadar data: Ph.D. Dissertation, University of Lausanne, Switzerland, 201 p.

Johnson, B., 2011, Evapotranspiration in the riparian zone of the lower Boise River with implications for groundwater flow: M.S. Thesis, Boise State University, 74 p.

Balkaya, C., 2010, Two-dimensional traveltime tomography of crosshole ground penetrating radar (GPR) data: Ph.D. Dissertation, Dokuz Eylul University, Turkey.

Cardiff, M., 2010, Data integration and inverse methods for characterization of multicomponent hydrologic systems: Ph.D. Dissertation, Stanford University.

Chidichimo, F., 2009, Hydrogeophysical characterization of heterogeneous porous media by means of self potential method: Ph.D. Dissertation, University of Basilicata, Italy.

Crespy, A., 2009, On the use of self-potential measurements to constrain hydromechanical disturbances in porous media and application to geothermal systems: Ph.D. Dissertation, University of Aix-Marseille III, France.

Dafflon, B., 2009, Integration of high-resolution geophysical data for the characterization of alluvial aquifers: Novel approaches and implications for hydrological predictions: Ph.D. Dissertation, University of Lausanne, Switzerland, 117 p.

Kulhlman, K., 2008, Laplace transform analytic element method for transient groundwater flow simulations: Ph.D. Dissertation, University of Arizona.

Ernst, J., 2007, 2-D finite-difference time-domain full-waveform inversion of crosshole georadar data, Ph.D. Dissertation, Nr. 17105, doi:10.3929/ethz-a-005465651, Naturwissenschaften, Eidgenössische Technische Hochschule ETH Zürich, Switzerland.

Nelson, G.K., 2007, Deterministic modeling of bromide tracer transport during the Tracer/Time-Lapse Radar Imaging Test at the Boise Hydrogeophysical Research Site, August 2001: M.S. Thesis, Boise State University, Boise, ID.

Pool, L., 2007, Determination of hydraulic conductivity from SH-waves: M.S. Thesis, Boise State University, Boise, ID.

Buursink, M.L., 2006, Application of borehole radar and Fresnel volume tomography to characterize a heterogeneous alluvial aquifer: Ph.D. Dissertation, Boise State University, Boise, ID, 284 p.

Fox, J.J., 2006, Analytical modeling of fully penetrating pumping tests at the Boise Hydrogeophysical Research Site for aquifer parameters and wellbore skin: M.S. Thesis, Boise State University, Boise, ID, 132 p.

Johnson, T.C., 2006, Fresnel volume ground penetrating radar attenuation difference tomography and incorporating geostatistical constraints into non-linear inverse problems: Ph.D. Dissertation, Boise State University, Boise, ID, 129 p.

Oldenborger, G.A., 2006, Advances in electrical resistivity tomography: Modeling, electrode position errors, time-lapse monitoring of an injection/withdrawal experiment, and solution appraisal: Ph.D. Dissertation, Boise State University, Boise, ID, 331 p.

Hughes, C.E., 2005, Comparison of empirical relationships for hydraulic conductivity using grain size distribution, packing, and porosity information from the Boise Hydrogeophysical Research Site, Boise, Idaho: M.S. Thesis, Boise State University, Boise, ID, 123 p.

Goldstein, S.E., 2004, Cross-well radar attenuation-difference tomography to monitor a bromide tracer test: M.S. Thesis, Boise State University, Boise, ID, 132 p.

Moret, G., 2003, P-wave velocity characterization of the Boise Hydrogeophysical Research Site: M.S. Thesis, Boise State University.

Reboulet, E.C., 2003, Quantitative analysis of unconsolidated coarse fluvial sediments from the Boise Hydrogeophysical Research Site: M.S. Thesis, Boise State University, 154 p.

Leven, C., 2002, Effects of heterogeneous parameter distributions on hydraulic tests – Analysis and assessment: Ph.D. Dissertation, University of Tubingen, Germany, 88 p.

**TECHNICAL REPORTS, by year:**

Aishlin, P., Thoma, M.J., and Barrash, W., 2013, Installation, maintenance, and offset calculation for tensiometers at the Boise Hydrogeophysical Research Site: Technical Report BSU CGISS 13-02, Boise State University, Boise, ID, 29 p.

Barrash, W. and Cardiff, M., 2013, Hydraulic conductivity distribution from multi-level slug tests and multivariate facies associations in a conglomeratic fluvial aquifer, Boise Hydrogeophysical Research Site: Technical Report BSU CGISS 13-03, Boise State University, Boise, ID, 71 p.

Johnson, B., Thoma, M., and Barrash, W., 2013, Neutron probe installation, calibration, and data treatment at the Boise Hydrogeophysical Research Site: Technical Report BSU CGISS 13-01, Boise State University, Boise, ID, 23 p.

Johnson, B., Thoma, M., and Barrash, W., 2013, Using differential GPS at the Boise Hydrogeophysical Research Site to determine installation and boundary locations: Technical Report BSU CGISS 13-04, Boise State University, Boise, ID, 19 p.

Thoma, M. and Barrash, W., 2012, Discharge-stage and discharge-inundation relationships for the Boise River at the Boise Hydrogeophysical Research Site: Technical Report BSU CGISS 12-03, Boise State University, Boise, ID, 22 p.

Miller, C., Barrash, W., Clement, W., and Routh, P., 2008, Controlled-source electromagnetic survey at New Hyde Park, New York: Technical report for U.S. EPA Grant X-96004601-0, CGISS Technical Report 08-01, Boise State University, Boise, ID, 43 p.

Thoma, M. and Nelson, G., 2008, Manual for development of a transient MODFLOW/ MT3DMS/SEAWAT simulation for the 2001 tracer test at the Boise Hydrogeophysical Research Site: CGISS Technical Report, 08-02, Boise State University, Boise, ID, 85 p.

Clemo, T., 2007, MODFLOW-2005 Ground-Water Model User Guide to the Adjoint State Based Sensitivity Process (ADJ), Technical Report BSU CGISS 07-01:CGISS Technical Report, Boise State University, Boise, ID.

Reboulet, E.C. and Barrash, W., 2003, Core, grain-size, and porosity data from the Boise Hydrogeophysical Research Site, Boise, Idaho: BSU CGISS Technical Report, 03-02, Boise State University, Boise, ID, 84 p.

Barrash, W., Clemo, T., Hyndman, D.W., Reboulet, E., and Hausrath, E., 2002, Tracer/Time-Lapse Radar Imaging Test; Design, operation, and preliminary results: Report to EPA for Grant X-970085-01-0 and to the U.S. Army Research Office for Grant DAAH04-96-1-0318, Center for Geophysical Investigation of the Shallow Subsurface Technical Report BSU CGISS 02-03, Boise State University, Boise, ID, 120 p.

Clemo, T., 2002, *MODFLOW-2000 for cylindrical geometry with internal flow observations and improved water table simulation:* Report to the U.S. Army Research Office for grants DAAH04-96-1-0318 and DAAD19-00-1-0454, and EPA grant X-970085-01-0, Center for Geophysical Investigation of the Shallow Subsurface Technical Report BSU CGISS 02-02, Boise State University, Boise, ID.

Hausrath, E.M., Barrash, W. and Reboulet, E.C., 2002, Water sampling and analysis for the Tracer/Time-Lapse Radar Imaging Test at the Boise Hydrogeophysical Research Site: Report to EPA for Grant X-970085-01-0 and to the U.S. Army Research Office for Grant DAAH04-96-1-0318, Center for Geophysical Investigation of the Shallow Subsurface Technical Report BSU CGISS 02-02, Boise State University, Boise, ID, 86 p.

Huang, K., Clemo, T., and Barrash, W., 1998, Program developments for modeling groundwater flow in three-dimensional heterogeneous aquifers with MODFLOW and MODFLOWP: Technical Report BSU CGISS 97-02, Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, Boise, Idaho, 31p.

**ABSTRACTS, by year:**

Barrash, W., Clemo, T., Johnson, T., Leven, C., Malama, B., and Nelson, G., 2007, Hydraulic tomography at the Boise Hydrogeophysical Research Site (abs.): SIAM Conference on Mathematical and Computational Issues in the Geosciences, March 19-22, 2007, Santa Fe, NM.

Barrash, W., Malama, B., Routh, P.S., Johnson, T.C., and Clemo, T., 2007, Joint inversion at the Boise Hydrogeophysical Research Site (abs.): AGU Spring Meeting, May 22-25, 2007, Acapulco, Mexico, Invited.

Malama, B., Kuhlman, K., and Barrash, W., 2007, Leakage theory for unconfined aquifers (abs.): AGU Spring Meeting, May 22-25, 2007, Acapulco, Mexico.

Barrash, W. and Routh, P.S., 2006, Boise Hydrogeophysical Research Site: Field-scale tests facility for addressing fundamental questions of environmental science (abs.): AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87, no. 52, Abstract H51D-0519.

Barrash, W. and Routh, P.S., 2006, Boise Hydrogeophysical Research Site, Phase 2: Community Asset: SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Barrash, W., Clemo, T., Johnson, T., Leven, C., and Nelson, G., 2006, Hydraulic tomography at the Boise Hydrogeophysical Research Site (abs.): Hydraulic Tomography Workshop, June 8-9, 2006, Boise State University, Boise, Idaho.

Barrash, W., Clemo, T., and Reboulet, E.C., 2006, Modeling and verifying multiscale, multifacies heterogeneity in a shallow fluvial aquifer (abs.): SEG Hydrogeophysics Workshop, July 31-August 2, 2006, Vancouver, BC.

Bradford, J.H., 2006, Pre-stack analysis of multi-fold GPR data for characterization of shallow groundwater systems: SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Bradford, J., 2006, Frequency dependent attenuation of ground-penetrating radar data: SAGEEP2006, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, Seattle, WA.

Bradford, J.H. and Clement, W., 2006, Accuracy and precision of porosity estimates based on velocity inversion of surface ground-penetrating radar data: A controlled experiment at the Boise Hydrogeophysical Research Site: AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87, no. 52, Abstract H43G-06.

Clemo, T. and Barrash, W., 2006, Sensitivity of flowmeter calibration to incoming flow through a well screen: Geological Society of America Ann. Mtg., Philadelphia, PA, Oct 22-25, 2006, GSA Abstracts with Programs v. 38, no. 7, p. 431.

Clemo, T. and Barrash, W., 2006, In-well fluid hydraulics simulation for modeling of borehole flowmeter response in a layered aquifer: MODFLOW and more 2006: Managing Ground-Water Systems: Poeter, Hill & Zheng (eds), International Ground Water Modeling Center, Golden CO, p. 721.

Dafflon, B., Holliger, K., and Tronicke, J., 2006, Local-scale characterization of the porosity structure of heterogeneous aquifers based on the conditional stochastic simulation of high-resolution geophysical data: SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Irving, J., Knoll, M., and Knight, R., 2006, Processing and inversion strategies for improving crosshole GPR velocity tomography: SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Johnson, T.C., Routh, P.S., Barrash, W., and Knoll, M.D., 2006, Time lapse imaging of a conductive tracer plume using GPR attenuation difference tomography, SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Johnson, T.C., Routh, P.S., Clemo, T., and Barrash, W., 2006, Plausible solution space sampling to quantify resolution and uncertainty (abs): AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87(52), Abstract NS23A-08.

Johnson, T.C., Routh, P.S., Clemo, T., Barrash, W., and Clement W., 2006, Incorporating geostatistical constraints in nonlinear inversion problems: Application to shallow aquifer borehole tomography problem, SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Leven, C., Barrash, W., and Dietrich, P., 2006, Application of the concept of sensitivity coefficients to pumping test data from the Boise Hydrogeophysical Research Site (abs.): AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87, no. 52, Abstract H43B-0506.

Malama, B., Barrash, W., Hyndman, D., and Nelson, G.K., 2006, Solute transport in a medium with spatially variable porosity (abs.): AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87, no. 52, Abstract H41G-05.

Miller, C.R. and Routh, P.S., 2006, Resolution analysis of geophysical images: Comparison of point spread function and region of data influence measures: SEG annual meeting in New Orleans, p. 1-4.

Muffels, C., Tonkin, M., Zhang, H., Anderson, M., and Clemo, T., 2006, Application of LSQR to calibration of a MODFLOW model: A synthetic study, MODFLOW and more 2006: Managing Ground-Water Systems – Conf. Proc., Poeter, Hill & Zheng (eds), International Ground Water Modeling Center, Golden CO, 283-287.

Mwenifumbo, C.J. and Knoll, M.D., 2006, Capacitive resistivity logging at the Boise Hydrogeophysical Research Site: SEG Hydrogeophysics Workshop, July 31-Aug 2, Vancouver, Canada.

Oldenborger, G.A., Knoll, M.D., Routh, P.S., and Barrash, W., 2006, Time-lapse ERT monitoring of an injection/withdrawal experiment, AGU-SEG Joint Assembly, Baltimore, May 22-26, H42B-05.

Routh, P.S., 2006, Funnel function approach to determine uncertainty; Some advances: AGU Fall Meeting, December 11-15, 2006, San Francisco, CA, EOS, v. 87, no. 52.

Routh, P.S. and Miller, C.R., 2006, Image interpretation using appraisal analysis: SAGEEP2006, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, Seattle, WA.

Routh, P., Sinha, S., and Anno, P.D., 2006, Reservoir heterogeneity at different scales using time frequency decomposition based on continuous wavelet transform: SEG Hydrogeophysics workshop, July 31-Aug 2, Vancouver, Canada.

Barrash, W., Clemo, T., Fox, J.J., and Johnson, T.C., 2005, Accounting for aquifer heterogeneity in analysis of the skin effect (abs.): AGU Fall Meeting, December 5-9, 2005, San Francisco, CA, EOS, v. 86, no. 52, Abstract H51A-0336.

Clement , W.P., Barrash, W., and Knoll, M.D., 2005, Reflectivity modeling of a ground penetrating radar profile of a saturated alluvial formation, EOS Trans. AGU, 86(18), Jt. Assem. Suppl., Abstract NS11A-03, 183. (23â€“27 May, New Orleans, LA).

Clemo, T., Barrash, W., and Johnson, T.C., 2005, Fluid mechanics of borehole flowmeters (abs.): AGU Fall Meeting, December 5-9, 2005, San Francisco, CA, EOS, v. 86, no. 52, Abstract H21C-1353.

Johnson, T.C., Routh, P.S., Clemo, T., Barrash, W., and Clement, W.P., 2005, Geostatistically constrained inversion and uncertainty estimation (abs.): AGU Fall Meeting, December 5-9, 2005, San Francisco, CA, EOS, v. 86, no. 52, Abstract H13C-1345.

Oldenborger, G.A., P.S. Routh, and M.D. Knoll, 2005, Sensitivity of electrical resistivity tomography data to electrode position, EOS Trans. AGU, 86(18), Jt. Assem. Suppl., Abstract NS12A-04, 183. (23â€“27 May, New Orleans, LA).

Routh, P.S., 2005, Appraisal analysis for nonlinear problems: Tool for image interpretation and survey design (abs.): AGU Fall Meeting, December 5-9, 2005, San Francisco, CA, EOS, v. 86, no. 52, Abstract H13C-1348 (Invited).

Routh, P.S., and Oldenburg, D.W., 2005, Survey design optimization using resolution measure of point spread function, EOS Trans. AGU, 86(18), Jt. Assem. Suppl., Abstract NS23A-02, 183. (23â€“27 May, New Orleans, LA).

Barrash, W., Kaleris, V., Clemo, T., Johnson, T., Leven, C., and Reboulet, E., 2004, In-well flow effects on borehole flowmeter profiles in long-screened wells (abs.): Spring AGU Meeting, May 17-21, 2004, Montreal, Canada, EOS, v. 85, no. 17.

Barrash, W., Knoll, M., Clement, W., Clemo, T., and Michaels, P., 2004, Determining distributions of hydrologic and geophysical parameters in a heterogeneous fluvial aquifer, Boise Hydrogeophysical Research Site (abs.): Geological Society of America 56th Ann. Mtg. Rocky Mountain Section and 100th Ann. Mtg. Cordilleran Section, Boise, ID, May 3-5, 2004, Abstracts with Programs, v. 36, no. 4, p. 76.

Clement, W.P., Barrash, W., and Knoll, M., 2004, Crosshole radar tomography in an alluvial aquifer near Boise, Idaho (abs.): Geol. Soc. Am. 56th Ann. Mtg. Rocky Mtn Sec. and 100th Ann. Mtg. Cord. Sec., Boise, ID, May 3-5, 2004. Abs. with Prog., v. 36, no. 4, p. 31.

Goldstein, S.E., Johnson, T.C., Knoll, M.D., Routh, P., and Barrash, W., 2004, Time-lapse imaging of a bromide tracer test in a coarse alluvial aquifer using crosswell radar attenuation-difference tomography (abs.): Spring AGU Meeting, May 17-21, 2004, Montreal, Canada, EOS, v. 85, no. 17.

Johnson, T.C., Barrash, W., and Knoll, M., 2004, Fresnel volume attenuation difference inversion of borehole georadar data using analytically computed sensitivities (abs.): Geological Society of America 56th Ann. Mtg. of Rocky Mountain Section and 100th Ann. Mtg. Cordilleran Section, Boise, ID, May 3-5, 2004, Abs. with Programs, v. 36, no. 4, p. 76.

Moret, G.J.M., Knoll, M.D., Barrash, W., and Clement, W.P., 2004, Investigating the hydrostratigraphy of an unconsolidated aquifer using crosswell seismic traveltime tomography (abs.): Spring AGU Mtg, May 17-21, 2004, Montreal, EOS, v. 85, no. 17.

Oldenborger, G.A., P.S. Routh, and M.D. Knoll, 2004, Effect of electrode position errors on electrical resistivity tomography data, EOS Trans. AGU, 85(17), Jt. Assem. Suppl., Abstract NS33A-02, 279. (17â€“22 May, Montreal, QC)

Johnson, T.C., Barrash, W., and Knoll, M., 2003, Imaging tracer movement in a heterogeneous sedimentary aquifer with Fresnel zone attenuation difference tomography (abs.): Geological Society of America Annual Meeting, November 2-5, 2003, Seattle, WA, Abstracts with Programs, v. 35, no. 6, p. 252.

Tronicke, J., Holliger, K., Barrash, W., and Knoll, M.D., 2003, Aquifer zonation using multivariate analysis of crosshole georadar tomograms (abs.): EGS-AGU-EUG Joint Assembly, Nice, France, April 6-11, 2003, Geophysical Research Abstracts, v. 5, 07006.

Barrash, W., Knoll, M.D., Clement, W.P., Clemo, T., and Michaels, P., 2002, Determining the three-dimensional distribution of permeability in a heterogeneous fluvial aquifer with hydrologic and geophysical methods, Boise Hydrogeophysical Research Site (abs.): Fall AGU Meeting, December 6-10, 2002, San Francisco, CA, EOS, v. 83, no. 47, p. F461 (Invited).

Johnson, T.C., Barrash, W., and Clemo, T., 2002, Modeling well-bore skin effects at pumping and observations wells under variable pumping rate (abs.): Fall AGU Meeting, December 6-10, 2002, San Francisco, CA, EOS, v. 83, no. 47, p. 453-454.

Leven, C., Barrash, W., Hyndman, D.W., and Johnson, T.C., 2002, Modeling a combined tracer and time-lapse radar imaging test in the heterogeneous fluvial aquifer at the Boise Hydrogeophysical Research Site (abs.): Fall AGU Meeting, December 6-10, 2002, San Francisco, CA, EOS, v. 83, no. 47, p. F487.

Moret, G., Buursink, M., Knoll, M.D., and Barrash, W., 2002, Comparing seismic and radar cross-hole tomography to quantify subsurface porosity (abs.): Subsurface Science Symposium, Inland Northwest Research Alliance/Idaho National Engr. and Env. Lab., Boise, ID, Oct. 13-16, 2002.

Clement, W.P., Liberty, L.M., and Barrash, W., 2001, Using cross-hole GPR reflections to improve tomographic imaging and hydrogeologic interpretation (abs.) Geological Society of America Annual Meeting, November 1-10, 2001, Boston, MA, Abstracts with Programs, v. 33, no. 6, p. A-45.

Purvance, D.T. and Barrash, W., 2000, The electrical-hydraulic conductivity correlation observed at the Boise Hydrogeophysical Research Site (abs.): Spring AGU Meeting, May 30-June 3, 2000, Washington, DC, EOS, v. 81, no. 19, May 9, 2000 Supplement, p. S212.

Barrash, W. and Clemo, T., 1999, Hierarchical geostatistics of porosity derived from neutron logs at the Boise Hydrogeophysical Research Site, Boise, Idaho (abs.): Geological Society of America Annual Meeting, October 25-29, 1999, Denver, CO., Abstracts with Programs, v. 31, no. 7, p. A149.

Clement, W.P., Liberty, L.M., Knoll, M.D., and Barrash, W., 1999, Imaging a shallow, unconfined, alluvial aquifer with radar and seismic methods at the Boise Hydrogeophysical Research Site (abs.): Geological Society of America Annual Meeting, October 25-29, 1999, Denver, CO., Abstracts with Programs, v. 31, no. 7, p. A144.

Reboulet, E.C. and Barrash, W., 1999, Identification of hydrostratigraphic facies in coarse, unconsolidated braided-stream deposits at the Boise Hydrogeophysical Research Site (abs.): Geological Society of America Annual Meeting, October 25-29, 1999, Denver, CO., Abstracts with Programs, v. 31, no. 7, p. A350.

Barrash, W. and M.D. Knoll, 1997, Research wellfield for calibrating geophysical measurements against hydrologic parameters (abs.), Fall AGU Meeting, San Francisco, CA, EOS, v. 78, no. 46, p. F319.

**RELATED REFERENCES:**

Barrash, W. and Morin, R., 1997, Recognition of units in coarse, unconsolidated braided-stream deposits from geophysical log data with principal components analysis: Geology, v. 25, no. 8, p. 687-690.

Barrash, W., Morin, R., and Gallegos, D.M., 1997, Lithologic, hydrologic and petrophysical characterization of a coarse-grained, unconsolidated aquifer, Capital Station site, Boise, Idaho: 32nd Symposium on Engineering Geology and Geotechnical Engineering, March 26-28, 1997, Boise, ID, p. 307-323.

McNeil, J.D., G.A. Oldenborger, and R.A. Schincariol, 2006, Quantitative imaging of contaminant distribution in heterogeneous porous media laboratory experiments, Journal of Contaminant Hydrology, CONHYD2000 (in press).

Michaels, P., 2006, Relating damping to soil permeability: International Journal of Geomechanics, ASCE, Vol. 6, No. 3, p. 158-165.

Michaels, P., 2001, Use of principal component analysis to determine down-hole tool orientation and enhance SH-waves: Journal of Environmental and Engineering Geophysics, EEGS, v. 6, no. 4, p. 175-183.

Michaels, P., 1998, In-situ determination of soil stiffness and damping: Journal of Geotechnical and Geoenvironmental Engineering, ASCE, v. 124, no. 8, p. 709-719.

Michaels, P. and Barrash, W., 1997, The effect of sparging on P and SH vertical seismic profiles: Proceedings of SAGEEP’97, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, March 23-26, 1997, Reno, NV, 1997, p. 781-789.

Michaels, P. and Barrash, W., 1996, The anomalous behavior of SH-waves across the water table: Proceedings of SAGEEP’96, The Symposium on the Application of Geophysics to Engineering and Environmental Problems, April 28-May 1, 1996, Keystone, CO, p. 137-145.

Miller, C.R., Routh, P., Brosten, T., and McNamara, J., 2008, Application of time-lapse ERT imaging to watershed characterization: Geophysics, in press.

Miller, C.R., Routh, P.S., Donaldson, P., and Oldenburg, D.W., 2005, Large-scale 3D inversion of frequency domain controlled-source electromagnetic data, EOS Trans. AGU, 86(18), Jt. Assem. Suppl., Abstract NS23A-04, 183. (23-27 May, New Orleans, LA).

Oldenborger, G.A., R.A. Schincariol, and L. Mansinha, 2003, Radar determination of the spatial structure of hydraulic conductivity, Ground Water, 41(1), 24-32.

Oldenborger, G.A., G.K.C. Clarke, and D.H.D. Hildes, 2002, Hydrochemical coupling of a glacial borehole_aquifer system, Journal of Glaciology, 48(162), 357-368.

Oldenborger, G.A., R.A. Schincariol, and L. Mansinha, 2002, Space-local spectral segmentation applied to characterizing the heterogeneity of hydraulic conductivity, Water Resources Research, 38(8), 1154, doi:10.1029/2001WR000496.

Qu, L., Routh, P. S., and Ko K., 2006, Wavelet domain deconvolution using cross validation in a periodic setting, IEEE Signal Processing Letters, v.13, no. 4, p.232-235.

Routh, P.S., Anno, and Baumel, R.T., 2005, Source estimation from pre-stack seismic data using nonlinear bounded minimization technique, EOS Trans. AGU, 86(18), Jt. Assem. Suppl., Abstract S44A-06, 183. (23-27 May, New Orleans, LA).

Schincariol, R.A., G.A. Oldenborger, J. McNeil, J.M. Markle, and L. Mansinha, 2003, Assessing the spatial variability of hydraulic conductivity and its role in solute and heat transport, GSA Abstracts with Programs, 35(6), Abstract 215-11, 527. (2-5 November, Seattle, WA)

Sinha, S., Routh, P. S., Anno, P. D., and Castagna, J., 2005, Scale attributes from continuous wavelet transform, SEG expanded abstracts, p. 779-781.

### Photo Gallery

Check out photos of the BHRS and the people involved with the project.

### Contact

For further information on the BHRS, contact Warren Barrash

ERB 3149

Boise State University

1910 University Drive

Boise, ID 83725