Robert W. Ritzi, Jr., PHD
Professor Emeritus. My research is focused on better understanding the flow of geofluids in the subsurface. I am interested in groundwater flow and the facilitated transport of solutes, particulates and heat within heterogeneous aquifer systems. I am also interested in the sequestration of CO2 within geologic reservoirs, and in the past influence of El Niño events on local watershed hydrology.
- Ph.D. in Hydrology and Water Resources from the University of Arizona, 1989
- MS in Geological Sciences from Wright State University, 1983
- BA in Geology from Wittenberg University, 1981
See publications listed below.
Funded Projects (NSF, DOE) have included:
- Understanding and modeling multi-scaled and hierarchical aquifer architecture
- Clarifying relationships between porosity, permeability and grain-size distributions
- Relating plume dispersion and retardation to sedimentary architecture within heterogeneous aquifer systems
- Quantifying and modeling processes associated with groundwater and surface water exchange of heat and nutrients in streambed sediments
- The influence of El Niño Southern Oscillation events on local hydrology
- Quantifying and understanding capillary trapping of CO2 (secondary seal effect) injected for deep geologic sequestration
Student Theses and Dissertations
(MS thesis unless otherwise indicated. Please also see the publication list below with references for the associated scientific articles published by these students)
- Blue, J., 2022, “Has winter weather in southwest Ohio been affected by the El Nino Southern Oscillation, the North Atlantic Oscillation, the Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation?”
- Cornett, T., 2021, “Grain-size and permeability of sediments within the hyporheic zone at the Theis Environmental Monitoring and Modeling Site, Great Miami River and Buried Valley Aquifer, Southwest Ohio, USA”
- Delaney, N., 2020, “Quantifying contributions to the variance of permeability and porosity within the western-belt sandstones of the Cypress Formation, Illinois Basin”
- Shelters, A., 2019, “Paradoxical behavior in groundwater levels in response to precipitation events”
- Ghose, R., 2017, "Linking the local vertical variability of permeability and porosity to newly interpreted lithofacies at the site of the Illinois Basin -Decatur Project, Decatur, Illinois"
- Soltanian, R., 2015, Ph.D. Dissertation: “Relating reactive transport to hierarchical and multiscale sedimentary architecture”
- Young, N., 2014, “Effect of rivers on groundwater temperature in heterogeneous buried-valley aquifers: extent, attenuation, and phase lag of seasonal variation"
- Grigsby, N., 2012, “Evaluating the effect of hyporheic exchange on intake temperatures of open-loop geothermal wells in glacigenic outwash aquifers”
- Zhou, Y., 2012, “The influence of streambed heterogeneity on hyporheic exchange in gravelly rivers”
- Verdibello, S., 2012, “Evaluating the Kozeny-Carman model for permeability in binary grain mixtures”
- Porter, L., 2011, “The Kozeny-Carman equation considered with a percolation threshold”
- Huang, L, 2010, “Transport through georeservoirs: spatial entropy in hydraulic properties, and temporal entropy in residence time distributions”
- Mastera, L., 2010, “Estimating permeability from the grain-size distributions of natural sediment”
- Ramanathan, R., 2009, Ph.D. Dissertation: “Linking plume spreading to hierarchical stratal architecture”
- Guin, A., 2009, Ph.D. Dissertation: “The continuity of high-permeability zones in sedimentary deposits”
- Esselburn, J.D., 2009, “Porosity and permeability in ternary sediment mixtures”
- Ferreira, J.T., 2009, “Measuring the permeability of open-framework gravel”
- Damico, J., 2007, “Geostatistical Characterization of Heterogeneity in the Aberjona River Aquifer, Woburn, Massachusetts”
- Conrad, C., 2006, “Air-Based Measurements of Permeability in Pebbly Sands”
- Guin, A., 2005, “Linking Indicator Geostatistics to Percolation Theory in the Analysis of Spatial Continuity of Permeable Sediments”
- Popken, E., 2005, “Spatial Correlation of Permeability at the Oyster Site, Virginia”
- Kamann, P., 2004, “Porosity and Permeability in Sediment Mixtures”
- Roy, Motusi, 2004, “The Spatial Distribution of Permeability in Depositional Sedimentary Structures”
- Proce, C.J., 2002, “Multi-Scale Heterogeneity of the Spiritwood Buried-Valley Aquifer Region Modeled Using Transition Probability Geostatistics”
- Patterson, W.E., 2002, “Characterization of Heterogeneity in the Confluence of the Mackinaw and Mahomet Bedrock Valleys, Illinois, and Implications for Interconnectedness of Sand and Gravel Lithofacies”
- Reed, D. 2001, “Characterization of Heterogeneity Using Indicator Geostatistics in the Mahomet Sand Aquifer, Champaign County, Illinois”
- Bogle, J.L, 2000, “Characterization of Macrodispersion As Related to Facies Proportions and Orientation in Buried-Valley Aquifers”
- Kausch, K.W., 1999, “Analysis of Heterogeneity in a Northern Reach of the Miami Valley Aquifer Using Indicator Geostatistics”
- Means, B., 1999, “Evaluating Three Aspects of Methods Used to Characterize Transport in Buried-Valley Aquifers: Number of Particles Simulated, Flow Domain Length, and Variogram Range”
- Klohe, C.A., 1998, “Determining the Effects of Heterogeneity on Macrodispersion in Buried-Valley Aquifers with Dipping Facies Assemblages”
- Masters, R.W., 1998, “Geostatistical Simulations of Binary Heterogeneity and Characterizations of Transport From a Point Source in Buried Valley Aquifers”
- Gillett, B.E., 1997, “Geostatistical Characterization of the Mahomet Sand, Champaign County, Illinois”
- Greer, C.B., 1997, “A Three-Dimensional Geostatistical Model for the White River Aquifer System, Marion County, Indiana”
- Slesers, A.J., 1997, “A Geostatistical Analysis of the White River Aquifer System Underlying Indianapolis and Marion County, Indiana”
- Titzel, C.S., 1997, “Quantification of the Permeability Distribution Within Sand and Gravel Lithofacies in a Southern Portion of the Miami Valley Aquifer System”
- Bukowski, J.M., 1996, “Modeling the Fresh Water - Salt Water Interface in the Pleistocene Aquifer on Andros Island, Bahamas”
- Henderson, R.F., 1996, “Relation Between Soil Moisture, Vegetation, and Climate in a S.W. Ohio Wetland During 1993 and 1994”
- Henn, K.W., 1996, “Evaluation of Pumping Strategies for Capturing Aqueous Tetrachloroethylene and Trichloroethylene at Wright-Patterson Air Force Base, Ohio”
- Kreswick, K., 1996, “The Hydrogeological and Hydrogeochemical Characterization of Sandy Hook, a Prograding Carbonate Sand Body, San Salvador, Bahamas”
- Podgorney, R.K., 1996, “Capture Zone Geometry of a Fractured, Carbonate Aquifer”
- Basial, M.J., 1995, “The Worth of Geostatistical Information in Conditional Simulation and Transport Simulation: An Evaluation of Aquitard Continuity in Glaciofluvial, Buried-Valley Aquifers”
- Brown, N.R., 1995, “An Evaluation of Three-Dimensional Aquitard Continuity Within A Southern Reach of the Miami Valley Aquifer, Southwestern Ohio: A Geostatistical Analysis”
- McAlleney, P.J., 1995, “Using Geostatistics to Evaluate the Three-Dimensional Hydrofacies Geometry within a Portion of the Miami Valley Aquifer Near Moraine, Ohio”
- Martin, J.T., 1995, “The Correlation Between Solid-Phase Radium and Dissolved Radon In a Fractured Carbonate Aquifer In Southwestern Ohio”
- Chapman, Mike, 1994, “A Study of the Ground Water Temperature Gradients Within a Constructed Wetland and Effects on the Establishment and Distribution of Vegetation.”
- Goel, Shubhra, 1994, “Understanding Ground Water Flow Through a Constructed Fen in the Beavercreek Wetlands,Ohio”
- McCready, Roger, 2004, “A Boron Plume Migration and Hydrogeological Interpretation Study Using Groundwater Flow and Solute Transport Modeling”
- Shestak, Carol, 2004, “Spatial Variability in the Hydrogeochemistry of a Near Surface Aquifer, and Spurious Factors Due to Temporal Variability”
- Zahradnik, Arthur, 2004, “Quantifying the Uncertainty Associated with Preferential Flow Paths for Flow and Transport Modeling in Glaciofluvial Buried Valley Aquifer Settings”
- Gall, Ivan, 2003, “The Correlation Between Bedrock Uranium and Dissolved Radon in Ground Water of a Fractured Carbonate Aquifer in Southwestern Ohio”
- Strecker, John, 2003, “Determination of Volumetric Soil Moisture Content Variations and the Relation to Vegetative Biomass in a Constructed Fen, Southwestern Ohio”
- Aguirre, Aida, 2002, “Finite Element Modeling of Seepage Pressures Within an Earthen Dam Under the Maximum Probable Flood”
- Russo, Luigi, 2002, “Evaluation of the Efficiency of Pressure Relief Wells”
- Balmer, Richard, 1991, “Evaluation of a Proposed Modification of the Slope Matching (SM) Method of Aquifer Test Analysis for the Determination of Transmissivity and Storativity”
- Field, Adrian, 1991, “Application of a Three Dimensional Ground Water Flow Model and Particle Tracking for Well Field Management”
- Smith, Ronald, 1991, “Use of Multilevel Slug Testing and Mass Transport Modeling to Evaluate Impacts of Heterogeneity on Nitrate Transport in Fractured Carbonate Rocks”
- Wright, Stephen, 1991, “Statistical Analysis of Spatial Variations in Regional Hydrogeochemistry Utilizing Factor Analysis and Correspondence Analysis”
- Andolsek, Robert, 1990, “Advective Mass Transport in an Anisotropic, Fractured, Carbonate Aquifer”
- Basile, Joseph, 1989, “A Dual Approach to Evaluating the Ground Water Pollution Potential to an Aquifer System in Cortland County, New York, Using Both the "DRASTIC" Methodology and the Estimation of Advective Fluid Velocities”
Peer-Reviewed Publications (Many are available at Dr. Ritzi's CORE Scholar Site)
* denotes current or former students or post-docs and WSU researchers
† denotes invited submissions
- R. Ritzi, Roberson, L., and M. Bottomley, (2021), El Niño Southern Oscillation (1896 to 2016): Quantifying Effects on Winter Precipitation and Temperature in Southwest Ohio, USA, Ohio Journal of Science, 121(2): 64-77, https://doi.org/10.18061/ojs.v121i2.7650
- Zhang, X, F Ma, S. Yin, C. Wallace, M. Soltanian, Z. Dai, Z. Ma, C. Zhan, and R. Ritzi, (2021), “Application of upscaling methods for fluid flow and mass transport in multi-scale heterogeneous media: A critical review,” Applied Energy, (303), https://doi.org/10.1016/j.apenergy.2021.117603
- Ershadnia, R., S. Hajirezaie; A. Amooie; C. Wallace; N. Gershenzon; S. Hosseini; D. Sturmer; R. Ritzi; and R. Soltanian, (2021), “CO2 Geological Sequestration in Multiscale Heterogeneous Aquifers: Effects of Heterogeneity, Connectivity, Impurity, and Hysteresis,” Advances in Water Resources, (151), https://doi.org/10.1016/j.advwatres.2021.103895
- Reesink, R., J. Best, C. Monson, J. Freiberg, and R. Ritzi, (2020), Interpreting pre-vegetation landscape dynamics: the Cambrian Lower Mount Simon Sandstone, Illinois, USA, Journal of Sedimentary Research, (90), doi: 10.2110/jsr.202.7
- Dai*, Z., C. Zhan, M. R. Soltanian*, R. Ritzi, (2019), Identifying spatial correlation structure of multimodal permeability in hierarchical media with Markov Chain approach, Journal of Hydrology, v.568 p. 703-715, 10.1016/j.jhydrol.2018.11.032
- Damico*, J.R., R.W. Ritzi, N.I. Gershenzon*, and R.T. Okwen, (2018),, Challenging geostatistical methods to represent heterogeneity in CO2 reservoirs: evaluation in the context of residual trapping of CO2, Environmental and Engineering Geoscience, 24 (4), 357-373, 10.2113/EEG-2116, Best Publication Award given in 2019 by the Association of Engineering Geologists
- Ritzi, R.W., R. Ghose*, M. Bottomley, A.J.H. Reesink, J. Best, J.T. Freiburg and N.D. Webb, (2018), Linking the local vertical variability of permeability and porosity to newly-interpreted lithofacies in the lower Mt. Simon CO2 reservoir, International Journal of Greenhouse Gas Control, 68, p. 26–41, http://dx.doi.org/10.1016/j.ijggc.2017.09.017
- Soltanian, M.R., M. Amooie, N.I. Gershenzon*, Z. Dai, F. Xiong, R.W. Ritzi, D. Cole, J. Moortgat, (2017), “Dissolution trapping of carbon dioxide in heterogeneous aquifers,” Environmental Science and Technology, 51 (13), pp 7732–7741, DOI: 10.1021/acs.est.7b01540
- †Gershenzon*, N.I, R.W. Ritzi, D. Dominic, E. Mehnert, and R. Okwen, (2017) “Effective constitutive relations for simulating CO2 capillary trapping in heterogeneous reservoirs with fluvial sedimentary architecture”, special issue of Geomechanics and Geophysics for Geo-Energy and Geo-Resources titled: Geologic CO2 Sequestration. 3(3), pp 221–223, DOI 10.1007/s40948-017-0057-3
- Gershenzon*, N.I, R.W. Ritzi, D. Dominic, E. Mehnert, and R. Okwen, (2017) “Capillary trapping of CO2 in heterogeneous reservoirs during the injection period”, International Journal of Greenhouse Gas Control (59), p. 13-23. http://dx.doi.org/10.1016/j.ijggc.2017.02.002
- Freiburg, J., R. Ritzi and K. Kehoe, (2016), Depositional and diagenetic controls on porosity within a deeply buried CO2 storage reservoir—the Cambrian Mt. Simon Sandstone, Illinois Basin, USA, submitted to International Journal of Greenhouse Gas Control, 55 (2016) 42–54, http://dx.doi.org/10.1016/j.ijggc.2016.11.005
- Gershenzon*, N.I, R.W. Ritzi, D. Dominic, E. Mehnert, R. Okwen, and C. Patterson, (2016), CO2 trapping in reservoirs with fluvial architecture: sensitivity to heterogeneity in permeability and constitutive relationship parameters for different rock types, Journal of Petroleum Science and Engineering, http://dx.doi.org/10.1016/j.petrol.2016.09.008
- Gershenzon*, N.I, R.W. Ritzi, D. Dominic, E. Mehnert, and R. Okwen, (2016) “Comparison of CO2 Trapping in Heterogeneous Reservoirs with Brooks-Corey and van Genuchten Capillary Pressure Curves”, Advances in Water Resources, 96, 225-236, http://dx.doi.org/10.1016/j.advwatres.2016.07.022
- Ritzi, R.W., J.T. Freiburg, N.D. Webb, (2016), “Understanding the (co)variance in petrophysical properties of CO2 reservoirs comprising fluvial sedimentary architecture,” International Journal of Greenhouse Gas Control, 51, p. 423–434, http://dx.doi.org/10.1016/j.ijggc.2016.05.001
- Gershenzon*, N.I, M. R. Soltanian*, R.W. Ritzi, D. Dominic, E. Mehnert, and R. Okwen, (2015) “Influence of small-scale, fluvial, sedimentary architecture on CO2 trapping processes in deep saliner”, Water Resources Research, 51, 8240–8256, doi: 10.1002/2015WR017638
- Gershenzon*, N.I, M. R. Soltanian*, R.W. Ritzi, D. Dominic, D. Keefer, E. Shaffer, B. Storsved ”(2015) How does the connectivity of open-framework conglomerates within multi-scale hierarchical fluvial architecture affect oil sweep efficiency in waterflooding? ” Geosphere, v. 11, no. 6, p. 2049–2066, doi:10.1130/GES01115.1
- †Ritzi, R.W., and R.M. Soltanian*, (2015), What have we learned from deterministic geostatistics at highly resolved field sites, as relevant to mass transport processes in sedimentary aquifers?, Journal of Hydrology, doi:10.1016/j.jhydrol.2015.07.049
- Soltanian*, M.R., R.W. Ritzi, C. Huang, Z. Dai, H. Deng " (2015) A note on upscaling retardation factor in hierarchical porous media with multimodal reactive mineral facies", Transport in Porous Media, doi:10.1007/s11242-015-0480-2
- Soltanian*, M.R., R.W. Ritzi, C. Huang, Z. Dai (2015) “Relating reactive solute transport to hierarchical and multiscale sedimentary architecture in a Lagrangian-based transport model: 1. Time-dependent retardation factor ," Water Resources Research, 51, doi:10.1002/2014WR016353.
- Soltanian*, M.R., R.W. Ritzi, C. Huang, Z. Dai " (2015) Relating reactive solute transport to hierarchical and multiscale sedimentary architecture in a Lagrangian-based transport model: 2. Particle displacement variance," Water Resources Research, 51, doi:10.1002/2014WR016354.
- Soltanian*, M.R., R.W. Ritzi, C. Huang, Z. Dai (2015) “Reactive Solute Dispersion in physically and chemically heterogeneous porous media with multimodal reactive mineral facies: The Lagrangian approach," Chemosphere, V 122, p. 235-244, doi:10.1016/j.chemosphere.2014.11.064
- Soltanian*, M.R., R.W. Ritzi (2014) “A new method for analysis of variance of the hydraulic and reactive attributes of aquifers as linked to hierarchical and multi-scaled sedimentary architecture”, Water Resources Research, doi:10.1002/2014WR015468.
- Soltanian*, M.R., R.W. Ritzi, Z. Dai, C. Huang, D. Dominic (2014) "Transport of kinetically sorbing solutes in heterogeneous sediments with multimodal conductivity and hierarchical organization across scales", Stochastic Environmental Research and Risk Assessment, doi: 10.1007/s00477-014-0922-3.
- Gershenzon*, N.I, M. R. Soltanian*, R.W. Ritzi, D. Dominic (2014) “Influence of small scale heterogeneity on CO2 trapping processes in deep saline aquifers”, Energy Procedia, V. 59, p. 166-173, doi: 10.1016/j.egypro.2014.10.363
- Gershenzon, N.I., Soltanian*, M. R., Ritzi, R.W., Dominic, D.F., (2014), Understanding the impact of open-framework conglomerates on water-oil displacements: Victor Interval of the Ivishak Reservoir, Prudhoe Bay Field, Alaska, Petroleum Geosciences, doi:10.1144/petgeo2014-017
- Ritzi, R.W., L. Huang*, R. Ramanathan*, and R. M. Allen-King, 2013, Horizontal spatial correlation of hydraulic and reactive transport parameters as related to hierarchical sedimentary architecture at the Borden research site, Water Resources Research, 49, 1–13, doi:10.1002/wrcr.20165
- Zhou, Y.Q.*, R.W. Ritzi, R. Soltanian*, and D.F. Dominic, 2013, The influence of streambed heterogeneity on hyporheic flow in gravelly rivers, Ground Water, doi: 10.1111/gwat.12048
- Porter*, L.B., R.W. Ritzi, L.J. Mastera*, D.F. Dominic, B. Ghanbarian-Alavijeh*, 2012, The Kozeny-Carman equation with a percolation threshold, Ground Water, DOI: 10.1111/j.1745-6584.2012.00930.x
- Huang*, L., R.W. Ritzi, R. Ramanathan*, 2011, Conservative models: parametric entropy vs. temporal entropy in outcomes, Ground Water, DOI: 10.1111/j.1745-6584.2011.00832.x
- Esselburn*, J.D., R.W. Ritzi, and D.F. Dominic, 2010, Porosity and permeability in ternary sediment mixtures, Ground Water, doi: 10.1111/j.1745-6584.2010.00744.x
- Ferreira*, J.T., R.W. Ritzi, and D.F. Dominic, 2010, Measuring the permeability of open-framework gravel, Ground Water, doi: 10.1111/j.1745-6584.2010.00675.x
- Ramanathan*, R., A. Guin*, R.W. Ritzi, D.F. Dominic, V.L. Freedman, T.D. Scheibe, and I.A. Lunt, 2010, Simulating the heterogeneity in channel belt deposits: Part 1. A geometric-based methodology and code, Water Resources Research, V. 46, doi:10.1029/2009WR008111
- Guin*, A., R. Ramanathan*, D.F. R.W. Ritzi, Dominic, I.A. Lunt, T.D. Scheibe, and V.L. Freedman, 2010, Simulating the heterogeneity in channel belt deposits: Part 2. Examples of results and comparison to natural deposits, Water Resources Research, V. 46, doi:10.1029/2009WR008112
- Ramanathan*, R., R.W. Ritzi, and R.M. Allen-King, 2010, Linking hierarchical stratal architecture to plume spreading in a Lagrangian-based transport model: Part II. Evaluation using new data from the Borden site, Water Resources Research, V. 46, W01510, doi:10.1029/2009WR007810
- Ritzi, R.W., and P. Bobeck, 2008, Comprehensive principles of quantitative hydrogeology established by Darcy (1856) and Dupuit (1857), Water Resources Research, 44, W10402, doi:10.1029/2008WR007002
- Guin*, A., and R.W. Ritzi, 2008, “Studying the effect of correlation and finite-domain size on spatial continuity of permeable sediments,” Geophysical Research Letters, V35, L10402, doi:10.1029/2007GL032717
- Ramanathan*, R., R. Ritzi, and C. Huang, 2008, “Linking hierarchical stratal architecture to plume spreading in a Lagrangian-based transport model,” Water Resources Research, V44, W04503, doi:10.1029/2007WR006282
- Sun, A.Y., R.W. Ritzi, and D. Sims, 2008, “Characterization and modeling of spatial variability in a complex alluvial aquifer: Implications on solute transport,” Water Resources Research, V44, W04402, doi:10.1029/2007WR006119
- Conrad*, C.M., R.W. Ritzi, and D.F. Dominic, 2008, “Air-based measurements of permeability in pebbly sands,” Ground Water, 46(1), p. 103-112,, doi:10.1111/j.1745-6584.2007.00379.x
- Dai*, Z., A. Wolfsberg, Z. Lu, and R. Ritzi, (2007), “Representing aquifer architecture in macrodispersivity models with an analytical solution of the facies transition probability matrix,” Geophysical Research Letters, 34, L20406, doi:10.1029/2007GL031608
- Kamann*, P.J., R.W. Ritzi, D.F. Dominic, and C.M. Conrad*, 2007, “Porosity and permeability in sediment mixtures,” Ground Water, doi: 10.1111/j.1745-6584.2007.00313.x
- Ritzi, R.W., and R.M. Allen-King, 2007, “Why did Sudicky (1986) find an exponential-like spatial correlation structure for hydraulic conductivity at the Borden research site?” Water Resources Research, 43, W01406doi: 10.1029/2006WR004935
- †Ritzi, R.W. and Z. Dai*, 2006, Introduction: Modeling groundwater flow and reactive transport in physically and chemically heterogeneous media, Geosphere, 2(2), doi: 10.1130/GES0202INT.1
- †Dai*, Z., J. Samper, and R.W. Ritzi, 2006, Identifying geochemical processes by inverse modeling of multicomponent reactive transport in the Aquia aquifer, Geosphere, 2(2), doi: 10.1130/GES00021.1
- Ritzi, R.W., and Z. Dai*, 2006, Guest Editors, Special Issue: Modeling groundwater flow and reactive transport in physically and chemically heterogeneous media, Geosphere, Volume 2(2), (eight papers).
- Ritzi, R. W., Z. Dai*, D. F. Dominic, and Y. Rubin, 2006, Reply to comment by Shlomo P. Neuman on “Spatial correlation of permeability in cross-stratified sediment with hierarchical architecture,” Water Resources Research, 42, W05602doi: 10.1029/2005WR004402
- Dai*, Z., R.W. Ritzi, and D.F. Dominic, 2005, “Improving permeability semivariograms with transition probability models of hierarchical sedimentary architecture derived from outcrop-analog studies,”Water Resources Research, 41, W07032doi: 10.1029/2004WR002515
- Ritzi, R. W.; Dai*, Z.; Dominic, D. F.; Rubin, Y. N., 2004, “Spatial correlation of permeability in cross-stratified sediment with hierarchical architecture,” Water Resources Research, 40(3), W03513doi: 10.1029/2003WR002420
- †Dai*, Z., Ritzi, R. W., C. Huang, Y. Rubin and D. F. Dominic, 2004, “Transport in heterogeneous sediments with multimodal conductivity and hierarchical organization across scales,” Journal of Hydrology, v. 294, Issues 1-3, p. 68-86.
- Proce*, C.J., R.W. Ritzi, D.F. Dominic, and Z. Dai*, 2004, “Modeling multiscale heterogeneity and aquifer interconnectivity,” Ground Water, 42(5), p. 658-670.
- †Dai*, Z., R.W. Ritzi, and D.F. Dominic, 2004, “Estimating parameters for hierarchical permeability correlation models,” in Aquifer Characterization, Eds. J. Bridge and D Hyndman, SEPM Special Publication No. 80, SEPM Publishing, Tulsa, p. 41-54.
- †Ritzi, R.W., Z. Dai*, D.F. Dominic, and Y.N. Rubin, 2003, “Review of permeability in buried-valley aquifers: centimeter to kilometer scales,” in Calibration and Reliability in Groundwater Modelling: A Few Steps Closer to Reality, K. Kovar, ed., IAHS Publ. no. 277.
- Dai, Z., R.W. Ritzi, D.F. Dominic and Y.N. Rubin, 2003, “Estimating spatial correlation structure for permeability in sediments with hierarchical organization, in Groundwater Quality Modeling and Management Under Uncertainty,” S. Mishra, Ed., American Society of Civil Engineers, Philadelphia, p. 83-100.
- †Ritzi, R.W., Z. Dai*, D.F. Dominic, and Y.N. Rubin, 2002, “Spatial structure of permeability in relation to hierarchical sedimentary architecture: centimeter to kilometer scales,” in Bridging the Gap between Measurement and Modeling in Heterogeneous Media, A. Findikakis, ed., IAHS and Lawrence Berkeley National Laboratory, CD ROM
- Bukowski*, J.M, R.W. Ritzi, C. Carney, and M. Boardman, 2001, “Explaining the thinness of fresh water lenses in the Pleistocene carbonate aquifer on Andros Island, Bahamas,” Journal of Ground Water, 39(5), p. 731-720.
- Ritzi, R.W., 2000, “Behavior of indicator variograms and transition probabilities in relation to the variance in lengths of hydrofacies,” Water Resources Research, 36(11), p. 3375-3381.
- Ritzi, R.W., D.F. Dominic, A.J. Slesers*, C.B. Greer*, E.C. Reboulet*, J.A. Telford*, R.W. Masters*, C.A. Klohe*, J.L. Bogle*, and Brent P. Means*, 2000, “Comparing statistical models of physical heterogeneity in buried-valley aquifers,” Water Resources Research, 36(11), p. 3179-3192.
- †Dominic, D.F., R.W. Ritzi, E.C. Reboulet*, and A.C. Zimmer*, 1998, “Geostatistical analysis of facies distributions: elements of a quantitative facies model,” in Hydrogeologic Models of Sedimentary Aquifers, Concepts in Hydrogeology and Environmental Geology No. 1, SEPM (Society of Sedimentary Geology) Publishers, p. 137-145.
- Podgorney*, R.K., and R.W. Ritzi, 1997, “Capture zone geometry of a fractured, carbonate aquifer,” Journal of Ground Water. 35(6), p. 1040-1050.
- †Ritzi, R.W., D.F. Dominic, and K. Kausch*, 1996, “Aquitard distribution in a northern reach of the Miami valley aquifer: 1) three-dimensional geostatistical evaluation of physical heterogeneity,” Hydrogeology Journal. 4(2), p. 12-24.
- †Dominic, D.F., R.W. Ritzi, and K. Kausch*, 1996, “Aquitard distribution in a northern reach of the Miami valley aquifer: 2) three-dimensional analysis of facies,” Hydrogeology Journal. 4(2), p. 25-35.
- Sminchak*, J.R., D.F. Dominic, and R.W. Ritzi, 1996, “Indicator geostatistical analysis of sand interconnections within a till,” Journal of Ground Water, 36(5), p. 1125-1131.
- Ritzi, R.W., D.F. Dominic, N.R. Brown*, K.W. Kausch*, P.J. McAlenney*, and M.J. Basial*, 1995, “Hydrofacies distribution and correlation in the Miami Valley aquifer system,” Water Resources Research, 31(12), p. 3271-3281.
- Gall*, I.K., R.W. Ritzi, A.D. Baldwin, P.D. Pushkar, C.K. Carney, and J.F. Talnagi, Jr., 1994, “The correlation between bedrock uranium and dissolved radon in ground water of a fractured carbonate aquifer in southwestern Ohio,” Journal of Ground Water, 33(2), p. 197-206.
- Ritzi, R.W., D.F. Jayne*, A.J. Zahradnik*, A.A. Field*, and G.E. Fogg, 1994, “Geostatistical modeling of heterogeneity in glaciofluvial, buried-valley aquifers,” Journal of Ground Water, 32(4), p. 666-674.
- Smith*, R.T, and R.W. Ritzi, 1993, “Designing a nitrate monitoring program in a heterogeneous, carbonate aquifer,” Journal of Ground Water, 31(4), p. 576-585.
- Ritzi, R.W., S.L. Wright*, B. Mann, and M. Cheng, 1993, “Considering the issue of temporal variability of regional hydrogeochemical data in a multivariate analysis of spatial variability,” Journal of Ground Water, 31(2), p. 221-229.
- Ritzi, R.W., and H.A. Andolsek*, 1992, “Relation between anisotropic transmissivity and azimuthal resistivity surveys in shallow, fractured, carbonate flow systems,” Journal of Ground Water, 30(5), p. 774-780.
- Ritzi, R.W., S. Sorooshian, and V.K. Gupta, 1991, “On the estimation of parameters for frequency domain models,” Water Resources Research, 27(5), p. 873-882.
- Ritzi, R.W., P.A. Hsieh, and S. Sorooshian, 1991, “The estimation of fluid flow properties from the response of water levels in wells to the combined atmospheric and earth tide forces,” Water Resources Research, 27(5), p. 883-893.
- Ritzi, R.W., and T.C.J. Yeh, 1988. “Comment on 'The Role of Groundwater in Delaying Lake Acidification' by M.P. Anderson and C.J. Bowser,” Water Resources Research, 24(5), p. 787‑790.