Skip to content


Ed PerfectEd Perfect


Department of Earth and Planetary Sciences
1412 Circle Drive
Knoxville, TN 37996-1410

Phone: (865) 974-6017
Fax: (865) 974-2368

I am a Professor specializing in Vadose zone Hydrology. I joined the Department of Earth and Planetary Sciences at the University of Tennessee, Knoxville, USA in August 2001. As a member of the Department's Hydrogeology Research Group I am actively involved in both research and teaching.

My research interests are centered on relations between pore space geometry and soil/rock hydraulic and chemical transport properties, as well as understanding the scale-dependency of these relations.  My research is, or has been, supported by the Petroleum Research Fund, National Science Foundation, U.S. Department of Energy, and U.S. Department of Defense.

I teach a variety of courses including a large introductory undergraduate course (The Earth's Environment), an upper-level undergraduate course in Hydrogeology, graduate courses on Data Analysis and Fractal Modeling, and specialized seminars for upper-level graduate students.

I was born and grew up in Peterborough, England.  As an undergraduate I attended the University of Newcastle-upon-Tyne, England, graduating in 1977 with a B.Sc. degree in Physical Geography.  In 1977 I moved to Ottawa, Canada.  I obtained a Masters degree in Physical Geography from Carleton University, Canada in 1980. In 1981 I moved to Ithaca, NY, USA to study with Professor R.D. Miller at Cornell University.  I obtained my Ph.D. degree in Agronomy (Soil Physics) from Cornell in 1986.  My doctoral studies focused on the upheaval of plants by ice segregation during soil freezing.

I returned to Canada in 1987 to spend eight years working as a Post-doctoral Research Scientist with Professor B.D. Kay at the University of Guelph, Ontario. My research activities during this time included work on soil freezing phenomena, soil structure and fractal geometry. In 1995 I joined the Department of Agronomy, at the University of Kentucky, USA as an Assistant Professor.  During my six years at Kentucky I taught undergraduate and graduate level courses in Soil Science, including Fundamentals of Soil Science, Soil Physics and Soil-Plant Relationships. I completed two Ph.D. students and continued my research on the application of fractal geometry to quantify soil structure.

In 2001 I joined the Department of Earth and Planetary Sciences at the University of Tennessee, Knoxville, USA, where I am a Professor within the Hydrogeology Research Group. My area of specialization is Vadose Zone Hydrology. My research interests are centered on relations between pore space geometry and soil hydraulic and chemical transport properties, and understanding the scale-dependency of these relations.  My research is, or has been, supported by the Petroleum Research Fund, National Science Foundation, U.S. Department of Energy, and U.S. Department of Defense. I teach a variety of courses including a large introductory undergraduate course (The Earth's Environment), an upper-level undergraduate course in Hydrogeology, graduate courses on Data Analysis and Fractal Modeling, and specialized seminars for upper-level graduate students. 

I have authored or coauthored over 120 scientific publications in refereed journals and 12 book chapters.  I have been invited to present lectures, workshops and/or seminars in Brazil, Spain and around the United States.  I served as Book Review Editor for the Vadose Zone Journal from 2009-11, and as an Associate Editor for the Soil Science Society of America Journal from 1994-99, I have guest edited several special issues of the journals Soil and Tillage Research, Ecological Modelling, and Vadose Zone Journal. I regularly review papers for a variety of journals as well as research proposals for governmental agencies such as the National Science Foundation, U.S. Department of Energy, and U.S. Department of Defense. I am an active member of the following organizations: American Geophysical Union, East Tennessee Geological Society, Geological Society of America, International Society of Soil Science, and the Soil Science Society of America.

Outside of the university environment I enjoy spending time with my wife and dogs at home and in various natural settings.  My hobbies include listening to music (rock and modern classical), reading (fiction and non-fiction), and growing cacti and succulents.  I also like soccer and am a life-long Peterborough United supporter.

Movement of chemicals in soil and rocks, and the resulting implications for agriculture and the environment, are topics of widespread public and scientific interest.  To control ground water pollution we must be able to predict transport processes within the variably-saturated (vadose) zone; contaminants must pass through this zone in order to reach groundwater.

Despite recent increased awareness of the critical role that the vadose zone plays in the hydrologic cycle, key constitutive relationships such as the relative permeability function are rarely determined directly.  Furthermore, existing models that are used to predict flow and transport in the vadose zone are often unreliable because they are based on empirical parameters that cannot be readily upscaled from the laboratory to the field.

My research mainly focuses on the development of more physically-based constitutive relationships for variably-saturated porous media.  I am particularly interested in the use of fractal geometry to model and upscale these relationships.  I am also investigating new/improved experimental techniques for measuring their input parameters.  My research program involves a combination of theory development and modeling, laboratory experimentation, as well as some fieldwork.  It always includes a strong quantitative component, and often involves the use of statistical analyses.

Recent and ongoing research projects can be grouped into the following categories:

  • modeling pore space geometry as related to hydraulic properties
  • fractal and lacunarity analyses of rock fracture patterns
  • upscaling aquifer/reservoir heterogeneity using geometrical multifractals
  • multifractal analysis of grayscale images
click image to enlarge
Pore-scale simulation of fluid flow through a fractal porous medium
click image to enlarge
Darcy-scale simulation of fluid flow through a multifractal field

click image to enlarge
Centrifuge system used for measuring relative permeability
  • determining point estimates of the capillary-pressure saturation relation
  • measuring relative permeability by transient flow centrifugation
  • electromagnetic methods for measuring soil water content
  • using neutron computed tomography to "see" the phase structure of water in porous media
  • predicting steady-state transport parameters from static physical properties
  • transient methods for determining transport parameters
  • transport of uranium in partially-saturated, coarse-textured sediments
click image to enlarge
Centrifuge system used for measuring particle-size distribution
  • determining the aggregate-size distributions of soil & marine sediments
  • use of SAXS and SANS to quantify pore-size distributions and pore-scale carbon contents
  • modeling geologic carbon sequestration in deep brine aquifers

I strongly believe that, because of their complexity, most vadose zone problems require a multidisciplinary approach.  My training and experience has been in Soil Physics, Hydrogeology, and Physical Geography.  While many of my primary research collaborations are with colleagues in these three areas, I enjoy working with scientists and engineers from a variety of different disciplines.  This is perhaps not surprising given my own diverse background.  Over the past few years I have worked closely with Agricultural Engineers, Applied Mathematicians, Chemists, Civil Engineers, Geophysicists, Microbiologists, Nuclear Physicists, Soil Chemists, and Structural Geologists on various projects.

My long-term goal is the development of a suite of physically-based, readily-measurable hydraulic functions that hopefully will supplant some of the more empirical approaches currently in use.  Much of my work has been at the pore-scale.  However, I am also interested in the measurement and analysis of large-scale physical properties and processes. 

I teach a variety of courses at the University of Tennessee, including a large introductory undergraduate course (The Earth's Environment, GEOL 103), an upper-level undergraduate course (Principles of Hydrogeology, GEOL 485), courses for graduate students (Data Analysis for Geoscientists, GEOL 425/525 and Fractal Models in Earth Science, GEOL 501), as well as an upper-level graduate course (Seminar in Hydrogeology, GEOL 685).  Brief descriptions of these courses are given below:

The objectives of this course are to: (i) explore the interrelationships between natural and man-made systems and changing planetary conditions, and (ii) evaluate the role that man and developing technologies play in maintaining and altering these planetary conditions.

This multidisciplinary course focuses on the physical properties of aquifers, principles of groundwater movement, saturated flow equations, analytical and numerical models, hydraulic properties of the vadose zone, pump test analyses, geologic controls, and hydrogeology of Tennessee.

This course provides an overview of sampling schemes, data exploration techniques, and statistical methods used in Earth and Planetary Sciences.  Both theory and applications are covered.  The SAS® software package is introduced and used to solve a variety of data analysis problems.  Topics covered include: sampling design, probability theory, parametric and non-parametric descriptive statistics, analysis of variance and comparison of means, linear, non-linear, and multiple regression analyses, cluster analysis, principal component analysis, time series analysis (autocorrelation and power spectra), and spatial (geo)statistics (semi-variance & Kriging).

This course provides an introduction to fractal geometry with emphasis on modeling natural and engineered porous media.  Both the theory and methods of fractal analysis are covered.  Topics include deterministic and statistical fractals, self-affine fractals, multifractals, percolation theory, anomalous diffusion, and renormalization group theory.  Programs for estimating fractal parameters (e.g., dimension and lacunarity) are explained and demonstrated.  The following applications in the geosciences are explored: characterizing coastlines, drainage basins and fracture networks, terrain simulation, modeling pore space geometry, flow and transport, rock fragmentation, spatial variability of mineral deposits, and temporal variability of earthquakes and floods.

This course provides a vehicle for the detailed exploration of selected specialized topics in hydrogeology.

  • Cropper, S.C., E. Perfect, C.-L. Cheng, L. McKay, and M. Kang. 2017. Evaluation of TrueCell program for estimating point capillary pressure – saturation parameters for Flint sand. Geoderma 287:90-97 (Download 833 KB)
  • Donnelly, B., E. Perfect, L.D. McKay, P.J. Lemiszki, V.H. DiStefano, L.M. Anovitz, J. McFarlane, and R.E. Hale, C.–L. Cheng. 2016. Capillary pressure – saturation relationships for gas shales measured using a water activity meter. J. Natural Gas Sci. 33:1342-1352 (Download 1,164 KB)
  • Leão, T.P., E. Perfect, and J.S. Tyner.  2015. Evaluation of Lichtenecker's mixing model for predicting effective permittivity of soils at 50 Mhz. Trans. ASABE  58:83-91 (Download 574 KB)
  • Perfect, E., and B. Donnelly. 2015. Bi-phase box counting: an improved method for the fractal analysis of binary images. Fractals 23, 1540010, doi: 10.1142/S0218348X15400101 (Download 957 KB)
  • Cheng, C.-L., E. Perfect, B. Donnelly, H.Z. Bilheux, A.S. Tremsin, L.D. McKay, V.H. DiStefano, J.C. Cai, and L.J. Santodonato. 2015. Rapid imbibition of water in fractures within unsaturated sedimentary rock. Adv. Water Resour. 77:82-89 (Download 1865 KB)
  • Roy, A., and E. Perfect. 2014. Lacunarity analyses of multifractal and natural grayscale patterns. Fractals 22, 1440003, doi10.1142/ S218348X14400039 (Download 1,023 KB)
  • Roy, A., E. Perfect, W.M. Dunne, and L.D. McKay. 2014. A technique for revealing scale-dependent patterns in fracture spacing data. J. Geophys. Res. 119:5979-5986 (Download 533 KB)
  • Cai, J.C., E. Perfect, E., C.-L. Cheng, and X.Y. Hu. 2014. Generalized modeling of spontaneous imbibition based on Hagen-Poiseuille flow in tortuous capillaries with variably shaped apertures. Langmuir 30(18): 5142-5151 (Download 1,219 KB)
  • Kang, M., E. Perfect, C.L. Cheng, H.Z. Bilheux, J. Lee, J. Horita, and J.M. Warren. 2014. Multiple pixel-scale soil water retention curves quantified by neutron radiography. Adv. Water Resour. 65:1-8 (Download 1,186 KB)
  • Perfect, E., C.-L. Cheng, M. Kang, H.Z. Bilheux, J.M. Lamanna, M.J. Gragg, and D.M. Wright. 2014. Neutron imaging of hydrogen-rich fluids in geomaterials and engineered porous media: A review. Earth Sci. Rev. 129:120-135 (Download 1,177 KB)
  • Cheng, C.-L., E. Perfect and R.T. Mills. 2013. Forward prediction of height-averaged capillary pressure-saturation parameters using the BC-vG Upscaler. Vadose Zone J. 12: doi:10.2136/vzj2012.0174 (Download 1,290 KB)
  • Kang, M., E. Perfect, C.L. Cheng, H.Z. Bilheux, M. Gragg, D.M. Wright, J.M. Lamanna, J. Horita, and J.M. Warren. 2013. Diffusivity and sorptivity of Berea sandstone determined using neutron radiography. Vadose Zone J. 12: doi:10.2136/vzj2012.0135 (Download 1,749 KB)
  • Cheng, C.-L., M.J. Gragg, E. Perfect, M. White, P.J. Lemiszki, and L.D. McKay. 2013. Sensitivity of injection costs to input petrophysical parameters in numerical geologic carbon sequestration models. Intl. J. Greenhouse Gas Control 18: 277-284 (Download 511 KB)
  • Kang. M., H. Z. Bilheux, S. Voisin, C.L. Cheng, E. Perfect J. Horita, and J.M. Warren, 2013. Water calibration measurements for neutron radiography: Application to water content quantification in porous media. Nuclear Instr. Method. Phys. Res. Section A 708: 24-31 (Download 2.02 MB)
  • Zhou, H, X. Peng, E. Perfect, T. Xiao, and G. Peng. 2013. Effects of organic and inorganic fertilization on soil aggregation in an Ultisol as characterized by synchrotron based X-ray micro-computed tomography. Geoderma 195-196: 23-30 (Download 924 KB)
  • Cheng, C.-L., M. Kang, E. Perfect, S. Voisin, J. Horita, H.Z. Bilheux, J.M. Warren, D.L. Jacobson, and D.S. Hussey, 2012. Average soil water retention curves measured by neutron radiography. Soil Sci. Soc. Am. J. 76:1184–1191, doi:10.2136/sssaj2011.0313 (Download 1.13 MB)
  • Kim, J.-W., M.C. Sukop, E. Perfect, Y.A. Pachepsky, and H. Choi. 2011. Geometric and hydrodynamic characteristics of three-dimensional saturated prefractal porous media determined with lattice Boltzmann modeling. Transp. Porous Media doi: 10.1007/s11242-011-9818-6 (Download 846 KB)
  • Zhou, H., E. Perfect, Y.Z. Lu, B.G. Li, and X.H. Peng. 2011. Multifractal analyses of grayscale and binary soil thin section images. Fractals 19:1-11 (Download 1.45 MB)
  • Lewis, D.B., D.B. Finkelstein, H.D. Grissino-Mayer, C.I. Mora, and E. Perfect. 2011. A multitree perspective of the tree ring tropical cyclone record from longleaf pine (Pinus palustris Mill.), Big Thicket National Preserve, Texas, United States, J. Geophys. Res., 116, G02017, doi:10.1029/2009JG001194 (Download 183 KB)
  • Koirala S.R., R.W. Gentry, P.J. Mulholland, E. Perfect, J.S. Schwartz, and G.S. Sayler. 2011. Persistence of hydrologic variables and reactive stream solute concentrations in an east Tennessee watershed. J. Hydrol. 401:221-230 (Download 2.91 MB)
  • Cropper, S.C., E. Perfect, E.H. van den Berg, and M.A. Mayes. 2011. Comparison of average and point capillary pressure-saturation functions determined by steady-state centrifugation. Soil Sci. Soc. Am. J. 75:17-25 Download (703 KB)
  • Roy, A., E. Perfect, W.M. Dunne, N, Odling, and J.-W. Kim. 2010. Lacunarity analysis of fracture networks: Evidence for scale-dependent clustering. J. Structural Geol. 32:1444-1449 Download (957 KB)
  • Leão, T.P., E. Perfect, and J.S. Tyner. 2010. New semi-empirical formulae for predicting soil solution conductivity from dielectric properties at 50 MHz. J. Hydrol. 393:321-330 Download (1.16 MB)
  • Zhou, H., E. Perfect, B.G. Li, and Y.Z. Lu. 2010. Effects of bit depth on the multifractal analysis of grayscale images. Fractals 18:127-138 Download (962KB)
  • Leão, T.P., E. Perfect, and J.S. Tyner. Estimation of soil water content using a 50 MHz impedance sensor: Soil texture, structure and salinity interactions. Trans. ASABE 53:163-170 Download (1.03 MB)
  • Zhuang, J., N. Goeppert, C. Tu, J.F. McCarthy, E. Perfect, and L.D. McKay. 2010. Colloid transport with wetting fronts: Interactive effects of solution surface tension and ionic strength. Water Res. 44:1270-1278 Download (610 KB)
  • Zhuang, J., J.S. Tyner, and E. Perfect. 2009. Colloid transport and remobilization in porous media during infiltration and drainage. J. Hydrol. 377:112-119. Download (424 KB)
  • Perfect, E., A.M. Tarquis, and N.R. Bird. 2009. Accuracy of generalized dimensions estimated from grayscale images using the method of moments. Fractals 17:365-385 Download (876 KB)
  • van den Berg, E.H., E. Perfect, C. Tu, P.S.K. Knappett, T.P. Leao, and R.W. Donat. 2009. Unsaturated hydraulic conductivity measurements with centrifuges: A review. Vadose Zone J. 8:531-547 Download (1488 KB)
  • Cihan, A., J.S. Tyner, and E. Perfect. 2009. Predicting relative permeability from water retention: A direct approach based on fractal geometry. Water Resour. Res. 45, W04404, doi:10.1029/2008WR007038 Download (448 KB)
  • Perfect, E., Y. Pachepsky, and M.A. Martín. 2009. Fractal and multifractal models applied to porous media. Vadose Zone J. 8:174-176 Download (492 KB)
  • Cihan, A., M.C. Sukop, J.S. Tyner, E. Perfect, and H. Huang. 2009. Analytical predictions and lattice Boltzmann simulations of intrinsic permeability for mass fractal porous media. Vadose Zone J. 8:187-196 Download (1386 KB)
  • Koirala, S.R., R.W. Gentry, E. Perfect, J.S. Schwartz, and G.S. Sayler. 2008. Temporal variation and persistence of bacteria in streams. J. Environ. Qual. 37:1559-1566 Download (1206 KB)
  • Koirala, S. R., E. Perfect, R. W. Gentry, and J. W. Kim. 2008. Effective saturated hydraulic conductivity of two-dimensional random multifractal fields. Water Resour. Res., 44, W08410 Download (1486 KB)
  • Tang, G., E. Perfect, E.H. van den Berg, M.A. Mayes, and J.C. Parker. 2008. Estimating effective hydraulic parameters of unsaturated layered sediments using a Cantor bar composite medium model. Vadose Zone J. 7:493-499 Download (1010 KB)
  • Logsdon, S.D., E. Perfect, and A.M. Tarquis. 2008. Multiscale soil investigations: Physical concepts and mathematical techniques. Vadose Zone J. 7:453-455 Download (492 KB)
  • Kenst, A., E. Perfect, S.W. Wilhelm, J. Zhuang, J.F. McCarthy, and L.D. McKay. 2008. Virus transport during infiltration of a wetting front into initially unsaturated sand columns. Environmental Sci. and Techn. 42:1102-1108 Download (465 KB)
  • Zhuang, J., J.F. McCarthy, E. Perfect, L.M. Mayer, and J.D. Jastrow. 2008. Soil water hysteresis in water-stable microaggregates as affected by organic matter. Soil Sci. Soc. Am. J. 72:212-220 Download (656 KB)
  • Roy, A., E. Perfect, W.M. Dunne, and L.D. McKay. 2007. Fractal characterization of fracture networks: An improved box-counting technique. J. Geophys. Res. 112:B12201, doi:10.1029/2006JB004582 Download (892 KB)
  • Cihan, A., E. Perfect, and J.S. Tyner. 2007. Water retention models for scale- variant and scale-invariant drainage of mass prefractal porous media. Vadose Zone J. 6:786-792, doi: 10.2136/vzj2007.0062 Download (998 KB)
  • Zhuang J., J.F. McCarthy, J.S.Tyner, E. Perfect, and M. Flury. 2007. In-situ colloid mobilization in Hanford sediments under unsaturated transient flow conditions: Effect of irrigation pattern. Environmental Sci. and Techn. 41:3199-3204. Download (176 KB)
  • Munkholm, L.J., E. Perfect, and J. Grove. 2007. Incorporation of water content in the Weibull model for soil aggregate strength. Soil Sci. Soc. Am. J. 71:682-691. Download (632 KB)
  • Díaz-Zorita, M., J.H. Grove, and E. Perfect. 2007. Sieving duration and sieve loading impacts on dry soil fragment size distributions. Soil Tillage Res. 94:15-20. Download (263 KB)
  • Kim, J.-W., E. Perfect, and H. Choi. 2007. Anomalous diffusion in two-dimensional Euclidean and prefractal geometrical models of heterogeneous porous media, Water Resour. Res. 43: W01405, doi:101029/2006WR004951. Download (1,027 KB)
  • Tanner, B.R., E. Perfect, and J.T. Kelly. 2006. Fractal analysis of Maine's glaciated shoreline tests established coastal classification scheme. J. Coastal Res. 22:1300-1304. Download (260 KB)
  • Perfect, E., R.W. Gentry, M.C. Sukop, and J.E. Lawson. 2006. Multifractal Sierpinski carpets: theory and application to upscaling effective saturated hydraulic conductivity. Geoderma 134:2410-252. Download (526 KB)
  • Ojeda, G., E. Perfect, J.M. Alcañiz, and O. Ortiz. 2006. Fractal analysis of soil water hysteresis as influenced by sewage sludge application. Geoderma 134:386-401. Download (546 KB)

Graduate Students

  • Jared Brabazon, M.Sc. (Geology), in progress (started January, 2017)
  • Chris Gates, M.Sc. (Geology), in progress (started August, 2016)
  • Molly Pattullo, M.Sc. (Geology), in progress (started August, 2014)
  • Blake Roberts, M.Sc. (Geology), graduated August, 2015
  • Brendan Donnelly, M.Sc. (Geology), graduated August, 2015
  • Clark Cropper, Ph.D. (Geology), graduated December 2014
  • Misun Kang, Ph.D. (Geology), graduated May, 2013
  • Ankur Roy, Ph.D. (Geology), graduated December 2013
  • Mike Gragg, M.Sc. (Geology), graduated December, 2012
  • Meghan Janzen, M.Sc. (Geology), graduated December, 2012
  • Andrew Moore, M.Sc. (Geology), graduated August, 2010
  • Tairone Leão, Ph.D. (Geology), graduated December, 2008
  • Richard Donat, M.Sc. (Geology), graduated December, 2008
  • Abdulla Cihan, Ph.D. (Biosystems Engineering), co-advisor, graduated May, 2008
  • Laura Taylor, M.Sc. (Geology), graduated May, 2007
  • Ankur Roy, M.Sc. (Geology), graduated May, 2006
  • Andrew Kenst, M.Sc. (Geology), graduated December, 2005
  • Jeremy Lawson, M.Sc. (Geology), graduated May, 2005
  • Martin Díaz-Zorita, Ph.D. (Soil Science), co-advisor, graduated May, 2001
  • Michael Sukop, Ph.D. (Soil Science), graduated May, 2001

Post-doctoral Researchers

  • Chu-Lin "Mike" Cheng, July, 2010 – December, 2013
  • Elmer van den Berg, August, 2006 - August, 2008

Visiting Scholars

  • Jianchao Cai, Associate Professor, China University of Geosciences, Wuhan, China, July, 2013 – July 2014
  • Zhou Hu, Ph.D. student, China Agricultural University, Beijing, China, September 2008 – August, 2009     
  • Jung-Woo Kim, Ph.D. student, GIST, South Korea, February – July, 2005
  • Silvia Stanchi, Ph.D. student, University of Torino, Italy, January – April, 2005
  • Lars Munkholm, Senior Scientist, Danish Institute of Agricultural Sciences, Foulum, Denmark, April – July, 2004
  • Gerardo Ojeda, Ph.D. student, University of Barcelona, Spain, May – July, 2003  
  • Gert van Dijk, M.Sc. student, Wageningen Agricultural University, the Netherlands, October, 1999 – February, 2000
  • Edwin De Winter, M.Sc. student, Wageningen Agricultural University, the Netherlands, May – September, 1995

The flagship campus of the University of Tennessee System and partner in the Tennessee Transfer Pathway.