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Stephen W. Wheatcraft
Department of Geological Sciences and Engineering/172
University of Nevada, Reno
Reno, NV 89509
Phone: (775) 784-1973
E-mail: wheatcraft unr.edu
Background:
Dr. Wheatcraft has been conducting research on issues of groundwater contamination for more than 30 years. He received his Ph.D. in 1979 from the University of Hawaii, Hawaii Institute of Geophysics. From 1978 to 1993, he was a Research Professor with the Desert Research Institute (DRI), part of the University of Nevada System. During this time, he was jointly-appointed with the Department of Geological Sciences at the University of Nevada, Reno (UNR). He taught is first class in 1979 and has been teaching in the department ever since. In 1993, he moved his main appointment from DRI to a tenured full professor position in the UNR Department of Geological Sciences. He has been a faculty member of the Interdisciplinary Graduate Program of Hydrologic Sciences since 1979. He has taught classes in Mathematical Methods, Numerical Methods, and Groundwater Modeling. He currently teaches one undergrad/grad class: Groundwater Hydrology, and three graduate-level classes: Contaminant Transport in Groundwater Flow Systems, Groundwater Hydraulics and Fortran for Scientists and Engineers.
Research:
Over his career at DRI and UNR, Dr. Wheatcraft has had nearly $8,000,000 in funded research grants from the National Science Foundation (NSF), the Department of Energy(DOE) and the Environmental Protection Agency (EPA). He has more than 50 publications in peer-reviewed journals and book chapters.
Dr. Wheatcraft’s Masters and Doctoral research involved laboratory and numerical modeling of sea water intrusion problems in Hawaii. He continues to maintain an interest in density-coupled flow and transport through field and modeling studies on Enewetak and Bikini atolls, and modeling studies of radionuclide transport and sea water intrusion at Amchitka Island in the Aleutian Chain, Alaska. These studies have been funded by DOE.
At DRI, Dr. Wheatcraft conducted numerous studies at the Nevada Test Site funded by DOE examining the transport of radionuclides in both the saturated and unsaturated zones.
Also at DRI, Dr. Wheatcraft worked with numerous colleagues and students on several EPA. grants (totaling several million dollars over a ten-year period) to develop new borehole geophysical methods for hydrogeologic characterization at hazardous (Superfund) waste sites.
EPA and the DOE (through the State of Nevada) also funded grants to Dr. Wheatcraft to develop new methods using fractal mathematics to model geologic heterogeneity of hydraulic properties such as hydraulic conductivity.
During the mid-90s, Dr. Wheatcraft was funded by NSF to develop (and test in the laboratory) new theoretical models of electrolyte molecular diffusion for high concentration contrasts (e.g., sea water to fresh water). Also under this grant, laboratory experiments were conducted with sand box models to develop test data sets for the classical Henry problem of sea water intrusion for the purpose of comparison to numerical and analytical solutions.
In recent years, Dr. Wheatcraft’s research has been primarily focused on the development of new theories for the transport of contaminants in highly heterogeneous aquifers. New forms of the advection-dispersion equation ADE) have been developed using fractional calculus. Fractional derivative forms of the dispersive terms in the ADE have been shown to do an excellent job of predicting (backcasting) the transport behavior of contaminant plumes in heterogeneous aquifer tracer tests (e.g. the MADE site and the Cape Cod site). He and his colleagues Dr. Mark Meerschaert and Dr. David Benson are currently working on developing multi-dimensional forms of the fractional ADE and generalizing the concepts of fractional vector calculus (e.g. fractional gradient, divergence and curl). This research is being funded by two grants from NSF totaling nearly $1,500,000.
Future Research
Work will continue on the fractional ADE, as discussed above. In addition, Dr. Wheatcraft would like to obtain funding to do carefully controlled laboratory tracer tests with tracers that can be detected in extremely low concentrations. It is at extremely low concentrations where the differences between traditional ADE and the fractional ADE are greatest.
Dr. Wheatcraft is also interested in obtaining funding to conduct additional field and modeling studies at Enewetak Atoll to gain a better understanding of atoll fluid flow and sea water transport mechanisms. This work would aid native populations of small islands in developing better, more efficient ways to manage scarce and fragile groundwater resources.
Honors and Awards:
His work (along with Dr. Scott Tyler) on the use of chaos to develop models of flow in unsaturated fractures was featured on NOVA and BBC’s Horizons (BBC’s equivalent of NOVA).
Dr. Wheatcraft was the 1990-91 Henry Darcy Distinguished Lecturer. This lecture series is funded by the National Groundwater Association (www.ngwa.org/ngwef/darcy.html ). He delivered his lecture, entitled: “Fractal Approaches to Modeling Geologic Variability in Aquifers”, to about 35 universities in the U.S. and Canada.
Dr. Wheatcraft was elected Fellow of the Geological Society of America (GSA) in 1995, and served as 2000 Chair of the Hydrogeology Division, GSA.
He was appointed to and served on the National Academy of Sciences Panel: “Conceptual Models of Flow and Transport in the Fractured Vadose Zone”, 1998-2000.
Former Students:
Dr. Wheatcraft has been the major advisor to ten Ph.D. students and 21 M.S. students. Eight of his former Ph.D. students are in tenure-track or tenured positions in universities such as UNR, Texas A&M, Ohio State , and Oregon State . He is currently advising four M.S. students and one Ph.D. student. Dr. Wheatcraft’s second Ph.D. student, Dr. Scott Tyler was himself the 1998-99 Henry Darcy Distinguished Lecturer and is now the Director of the UNR Hydrologic Sciences Program.
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