USGS Professional Pages
 
|
 Daniel H DoctorGeologist Contact Info |
Name: | Bedrock structural controls on the occurrence of sinkholes and springs in the northern Great Valley karst, Virginia and West Virginia. |
| Citation: | Doctor, D.H., Weary, D.J., Orndorff, Randall C., Harlow, George E., Jr., Kozar, Mark D., Nelms, David L. (2008) Bedrock structural controls on the occurrence of sinkholes and springs in the northern Great Valley karst, Virginia and West Virginia. In: Sinkholes and the Engineering and Environmental Impacts of Karst (L.B. Yuhr, E.C. Alexander, Jr., and B.F. Beck, eds.), Proceedings of the Eleventh Multidisciplinary Conference, Geotechnical Special Publication no. 183, American Society of Civil Engineers, p.12-22 |
| Summary: | The Shenandoah Valley is one of the fastest developing areas in the United States. Due to the high population pressures, water resource evaluations are increasingly important. A geologic framework is critical for understanding how water moves through this complex terrain, which is a mixture of karstic carbonate rocks and non-karstic siliclastic rocks, both exhibiting a high degree of structural control on water flowpaths. In conjunction with geologic mapping at 1:24,000 scale in this region, I am working on a new conceptual model of the geologic controls on groundwater movement in this region that can be used to inform water resource investigations, as well as the geomorphic history of the Great Valley. |
Download: | File (size:0.63 MB) |
Name: | Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream |
Citation: | Doctor, D.H., Kendall, C., Sebestyen S.D., Shanley, J.B, Ohte, N., and Boyer, E.W. (2008) Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream. Hydrological Processes. vol. 22, p. 2410-2423 |
Summary: | Climate change is intimately tied to carbon dioxide concentrations in the atmosphere; however, links within the carbon cycle between the atmosphere and the terrestrial hydrosphere are still poorly understood. Stable isotopes of carbon are ubiquitous tracers of the carbon cycle, and aid in calibrating many carbon budget models. This paper presents a high-resolution data set illustrating the isotopic evolution of carbon dioxide lost from stream water in first order reaches, a process that may play a significant role in determining the quantity and isotopic composition of atmospheric CO2 derived from natural terrestrial sources. |
Name: | Interpretation of water chemistry and stable isotope data from a karst aquifer according to flow regimes identified through hydrograph recession analysis |
| Citation: | Doctor D.H., and Alexander E.C., Jr. (2005) Interpretation of water chemistry and stable isotope data from a karst aquifer according to flow regimes identified through hydrograph recession analysis. U.S. Geological Survey Scientific Investigations Report 2005-5160, p. 82-92 |
| Summary: | One of the difficulties in integrating hydrologic data with geochemical data in time series is that the frequency of collection of the physical hydrologic data is normally much higher than the frequency of chemical sampling. This leads to the problem of aliasing across the higher frequency data, and results in high uncertainty when estimating water quality loads at points of discharge such as streams, springs, and wells. I developed an approach that aims to minimize this uncertainty. A method is presented for interpreting water quality data within discrete flow regimes of karst springs. Flow regimes are first defined based upon breaks in slope of the log-transformed discharge of spring hydrographs during recession periods. Water quality data from samples collected within each flow regime at different time periods are then grouped and can be statistically analyzed. Through this approach, chemical variability within established flow regimes reveal information about the function of the aquifer system. |
Download: | File (size:0.66 MB) |
Name: | Quantification of karst aquifer discharge components through end-member mixing analysis using natural chemistry and stable isotopes as tracers |
Citation: | Doctor, D.H., Alexander, E.C., Jr., Petric, M., Kogovsek, J., Urbanc, J., Lojen, S., and Stichler, W. (2006) Quantification of karst aquifer discharge components through end-member mixing analysis using natural chemistry and stable isotopes as tracers. Hydrogeology Journal, v. 14, p. 1,171, 1,191 |
Summary: | An important question for maintaining a clean and potable ground water supply is what are the sources of water to the supply well and how do those sources change under transient hydrologic conditions? The answer has less to do with the theoretical aquifer properties one might obtain from a pumping test than with the actual flow paths to the well and the changes in the quality of the water along those flow paths. In fractured rock and karst terrains, this complex issue is exacerbated by the high heterogeneity of the aquifer properties that allow for multiple compartments of water stored in the aquifer to feed a point of discharge under different head conditions. In this paper, I demonstrated a method through which quantities of water derived from different storage compartments within a single aquifer could be estimated across transient hydrologic conditions. Through this method no artificial tracing is necessary; instead, the approach takes advantage of the naturally present water chemistry of the well water in order to differentiate among the sources feeding the well or spring. |
Name: | Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest |
Citation: | Sebestyen, S.D., E.W. Boyer, J.B. Shanley, C. Kendall, D.H. Doctor, G.R. Aiken, and N. Ohte (2008), Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest, Water Resources Research, 44, W12410, doi:101029/2008WR006983 |
Summary: | In this study the dynamics of nitrogen and carbon nutrient loadings to streams during snowmelt runoff were investigated at the Sleepers River Research Watershed, Vermont. |
Doctor, D.H., Schwartz, B.F., and Gary, M.O. (2009) Preliminary development of a statistically based karst classification system, PHORMS. In: Proceedings of the Fifteenth International Congress of Speleology, July 19-26, 2009, Kerrville, Texas (W.B. White, ed.), vol. 2, p. 843-848.
Tobin, B., and Doctor, D.H. (2009) Estimating karst conduit length using conductivity and discharge measurements in Lilburn Cave, Kings Canyon National Park, California. In: Proceedings of the Fifteenth International Congress of Speleology, July 19-26, 2009, Kerrville, Texas (W.B. White, ed.), Vol. 3, p. 1702-1706.
Doctor, D.H., Orndorff, W., and Orndorff, R.C. (2009) Overview of the Shenandoah Valley karst of Virginia and West Virginia. In: Guidebook for Excursion No.1, Coast to Coast Excursion, Eastern Segment, July 27 to August 5, 2009 (K.W. Stafford and B. Fratesi, eds.), Excursion Guidebook for the Fifteenth International Congress of Speleology of the International Union of Speleology. Greyhound Press: Huntsville, Alabama, p. 84-96.
Doctor, K.Z. and Doctor, D.H., Kronenfeld, B., Wong, D.W.S., and Brezinski, D.K. (2008) Predicting Sinkhole Susceptibility in Frederick Valley, Maryland, Using Geographically Weighted Regression. In: Sinkholes and the Engineering and Environmental Impacts of Karst (L.B. Yuhr, E.C. Alexander, Jr., and B.F. Beck, eds.), Proceedings of the Eleventh Multidisciplinary Conference, Geotechnical Special Publication no. 183, American Society of Civil Engineers, p.243-256.
Doctor, D.H. , Weary, D.J., Orndorff, Randall C., Harlow, George E., Jr., Kozar, Mark D., Nelms, David L. (2008) Bedrock structural controls on the occurrence of sinkholes and springs in the northern Great Valley karst, Virginia and West Virginia. In: Sinkholes and the Engineering and Environmental Impacts of Karst (L.B. Yuhr, E.C. Alexander, Jr., and B.F. Beck, eds.), Proceedings of the Eleventh Multidisciplinary Conference, Geotechnical Special Publication no. 183, American Society of Civil Engineers, p.12-22.
Doctor, D.H., Weary, D.J., Epstein, J.B., and Orndorff, R.C. (2008) A Karst Aquifer Map for the United States—Is it possible?: U.S. Geological Survey Karst Interest Group Proceedings, Bowling Green, Kentucky, May 27-29, USGS Scientific Investigations Report 2008-5023, p. 34-36.
Doctor D.H. (2008) Hydrologic connections and dynamics of water movement in the Classical Karst (Kras) aquifer: evidence from frequent chemical and stable isotope sampling. Acta Carsologica, vol. 37, no.1, p. 101-123.
Sebestyen, S.D., E.W. Boyer, J.B. Shanley, C. Kendall, D.H. Doctor, G.R. Aiken, and N. Ohte (2008), Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest, Water Resour. Res., 44, W12410, doi:101029/2008WR006983.
Doctor, D.H., Kendall, C., Sebestyen S.D., Shanley, J.B, Ohte, N., and Boyer, E.W. (2008) Carbon isotope fractionation of dissolved inorganic carbon (DIC) due to outgassing of carbon dioxide from a headwater stream.Hydrological Processes vol. 22, p. 2410-2423.
Ohte N., Dahlgren R.A., Silva S.R., Kendall C., Kratzer C.R., Doctor D.H. (2007) Sources and transport of algae and nutrients in a Californian river in a semi-arid climate. Freshwater Biology 52, p. 2476–2493, doi:10.1111/j.1365-2427.2007.01849.x
Doctor D.H., Alexander E.C., Jr., Petric M., Kogovsek J., Urbanc J., Lojen S., and Stichler W. (2006) Quantification of karst aquifer discharge components through end-member mixing analysis using natural chemistry and isotopes as tracers. Hydrogeology Journal 14(7): 1171-1191.
Doctor D.H., and Alexander E.C., Jr. (2005) Interpretation of water chemistry and stable isotope data from a karst aquifer according to flow regimes identified through hydrograph recession analysis. U.S. Geological Survey Scientific Investigations Report 2005-5160, p. 82-92.
Ohte N., Sebestyen S.D., Shanley J.B., Doctor D.H., Kendall C., Wankel S.D., and Boyer E.W. (2004) Tracing sources of nitrate in snowmelt runoff using a high-resolution isotopic technique. Geophysical Research Letters, 31(21), L21506
Kendall C. and Doctor D.H. (2003) Stable Isotope Applications in Hydrologic Studies. In: Treatise on Geochemistry, Vol. 5, Chapt. 11, pp. 319-364. Elsevier: Amsterdam.
Doctor, D.H. (2002) The Hydrogeology of the Classical Karst (Kras) Aquifer of Southwestern Slovenia. Ph.D. dissertation, University of Minnesota, Minneapolis, 252 pp.
Doctor, D. (2001) Experiments in mineral dissolution kinetics: a guide to their design and interpretation. Minnesota Department of Natural Resources, Division of Lands and Minerals, Reclamation Section: St. Paul, MN, 20 pp.
Doctor, D., Leopold E., and Lapakko K. (2001) Carbonate mineral dissolution: reaction rates and mechanisms. Minnesota Department of Natural Resources, Division of Lands and Minerals, Reclamation Section: St. Paul, MN, 69 pp.
Phillips, E., Doctor, D., Leopold, E., and Lapakko, K. (2001) Dissolution of silicate minerals present in Duluth Complex and Archean Greenstone formations (Literature Summary) Minnesota Department of Natural Resources, Division of Lands and Minerals, Reclamation Section: St. Paul, MN, 36 pp.
Doctor, D.H., M. Horvat and S. Lojen (2000) A stable isotope investigation of the Classical Karst aquifer: Evaluating karst groundwater components for water quality preservation. Acta Carsologica, vol. 29, no. 1.
Alexander, E. Calvin, Jr., Scott C. Alexander, Sheila R. Grow, Betty J. Wheeler, Roy A. Jameson, Lifeng Guo, and Daniel H. Doctor (1999) Geochemical and isotopic evidence for multiple residence time in the same aquifer, Symposium on Karst Modeling, February 24-27, 1999, Charlottesville, VA., Karst Modeling, KWI Special Publication 5, Karst Waters Institute.
Abstracts:
Doctor, D.H., Orndorff, W., and Plummer, L.N. (2008) A Proposed Hypogenic Origin of Karst in the Shenandoah Valley, Virginia and West Virginia. Geological Society of America Abstracts with Programs, Vol. 40, No. 6, p. 341
Weary, D.J., Doctor, D.H., Epstein, J.B., and Orndorff, R.C. (2008) Characterizing Regional Karst Types Under the Framework of the New National Karst Map: U.S. Geological Survey Karst Interest Group Proceedings, Bowling Green, Kentucky, May 27-29, 2008, USGS Scientific Investigations Report 2008-5023, p. 25-33.
Weary D.J., Doctor D.H., Orndorff R.C., Harlow G.E., Jr (2007) Structural control of spring locations in the northern Shenandoah Valley, Virginia and West Virginia: interpretation of geologic controls on ground-water flow paths in folded and faulted carbonate rocks. Geological Society of America Abstracts with Programs, Vol. 39, No. 2, p. 99.
Doctor, D.H. (2007) Geologic controls on karst aquifer function as reflected in hydrographs and chemographs: relating recession coefficients to flow regimes, chemical loads, and fractal dimensions.Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 516.
Tobin, B.W. and Doctor, D.H. (2007) Estimating karst conduit length using conductivity and discharge measurements in Lilburn Cave, Kings Canyon National Park, California. Geological Society of America Abstracts with Programs, Vol. 39, No. 6, p. 376.
Doctor, D.H., Sebestyen, S.D., Aiken, G.R., Shanley, J.B., Kendall, C. and Boyer, E.B. (2006) Carbon Isotope Composition as an Indicator of DOC Sources to a Stream During Events in a Temperate Forested Catchment. Eos Trans. AGU, 87(52), Fall Meet. Suppl., Abstract B33A-1154
Doctor D.H., Rollog M.E., Silva S.R., Kendall C. (2005) Diel Stable Isotopic Variation of Dissolved Oxygen, Carbon, Nitrate and Particulate Organic Matter in the San Joaquin River, California, Eos Trans. AGU, 86(52), Fall Meet. Suppl., Abstract H13F-1377.
Doctor D.H., S.R. Silva, C. Kendall, C.C.Y. Chang, J. Hench, and W.E. Fleenor (2005) An Investigation of Low Dissolved Oxygen Conditions in the San Joaquin River Using Stable Isotopic Techniques. Abstract, 7th Biennial State of the San Francisco Estuary Conference, Oakland, CA, Oct 4-6, 2005.
Doctor D.H., Kendall, C., Sebestyen, S.D., Shanley, J. (2004) Carbon isotopes as tracers of groundwater and soil water contributions to streamflow in a forested headwater catchment. GSA Abstracts with Programs, vol. 36, No.5. Geological Society of America annual meeting, Denver, CO, Nov. 7-10, 2004.
Doctor D.H., Ohte, N., Kendall, C., Silva, S.R. (2004) Carbon isotopes as a tool for investigating sources and carbon cycling in the San Joaquin River. Abstracts: 3rd Biennial CALFED Bay-Delta Program Science Conference, Oct 4-6, 2004 Sacramento, CA.
Doctor D.H. (2003) Using Hydrograph Recession Analysis for Linking Hydrology to Chemistry: A Flow Regime Approach. Eos Trans. AGU, 84(47), Fall Meet. Suppl., Abstract H42K-02.
Doctor D.H., Sebestyen S.D., Ohte, N., Wankel, S., Shanley, J., and Kendall, C. (2003) Carbon and Nitrogen Isotopes as Indicators of Streamflow Generation Processes: Use of Automated CF-IRMS Analysis Techniques for d13C of DIC and DOC and d15N and d18O of Nitrate. Presented at the 10th Annual Canadian Continuous-Flow Isotope Ratio Mass Spectrometry (CF-IRMS) Workshop, Aug. 10-13, Winnipeg, Canada.
Doctor D. H., E.C. Alexander, Jr., and W. Stichler (2001) Isotopic tracers do not usurp groundwater chemistry or vice versa: Combined isotopic and chemical tracers in upper Mississippi Valley and Slovenian karst aquifers yield more information than either would alone. EOS, Trans. Amer. Geophys. Union, 2001 Spring Meeting, v. 82, n. 20, May 15, 2001. Supplement, p. S172.
Doctor D., Horvat, M. and Longinelli, A. (1999) An Investigation into the Fate and Transport of Mercury within the Classical Karst, Using Environmental Isotopes as Tracers. V International Conference on Mercury as a Global Pollutant, Rio De Janeiro, May 23 to 28, 1999, Program with abstracts.
Doctor D.H. and Alexander E.C., Jr. (1998) Results of Monitoring the Isotopic Composition and Hydrology of Infiltrating Drip Waters in Mystery Cave, Minnesota. EOS, Trans. Amer. Geophys. Union, 1998 Spring Meeting, v. 79, n. 17, Supplement, April 28, 1998, p. S83-84.
Doctor D.H., M. E. Berndt, W. E. Seyfried, Jr. (1995) An evaluation of near-equilibrium calcite kinetics at 100 degrees C using an isotopic doping technique. Geological Society of America, 1995 annual meeting, Abstracts with Programs - Geological Society of America, 27 (6), p. 249.
| Geologic Processes | geochemistry |
| Geologic Processes | land subsidence |
| Geologic Processes | water chemistry |
| Geographic Analysis and Mapping | maps and atlases |
| Hydrologic Processes | ground-water flow |
| Hydrologic Processes | water circulation |
| Techniques and Methods | isotopic analysis |
| Water Resources | aquifers |
| Water Resources | movement and recharge |
| Water Resources | water budget |
| Geologic Processes | faulting |
| Geologic Processes | folding |
| State | Research Center |
| VA | National Center |
Map of my primary study area (outlined in yellow) within the central Appalachian Great Valley region including all of the Shenandoah Valley. Karst areas are highlighted in light blue.
PRIMARY RESEARCH INTERESTS
Karst (geology, hydrology, geomorphology, speleology, paleoclimatic records)
Geologic mapping in the Appalachians
Biogeochemistry of streams and rivers (carbon and nitrogen cycling)
Applications of stable isotopes as tracers in hydrogeology
U.S. Department of the Interior |
U.S. Geological Survey
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Page Last Modified: 2009-08-19 14:56:32
