Conclusions
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Concluding Catchment Statements Plot Scale Scale A Shortcourse on Isotope Hydrology Concluding Statements Prof. Jeff McDonnell Richardson Chair in Watershed Science Dept. of Forest Engineering Oregon State University © Oregon State University Concluding Hillslope Isotope Statements Plot Scale Hydrology Basics Related programs to consider in the future The International Atomic Energy Agency (IAEA) The UNESCO-IAEA Joint International Isotope Hydrology Program The International Commission on Tracers The International Association of Hydrological Sciences PUB Initiative IGBP Biospheric Aspects of the Hydrological Cycle © Oregon State University Concluding Hillslope Isotope Statements Plot Scale Hydrology Basics Web sites to check out IGBP http://www.igbp.kva.se/cgi-bin/php/frameset.php GEWEX http://www.gewex.org/ WCRP http://www.wmo.ch/web/wcrp/wcrp-home.html JWP http://www.igbp.kva.se/cgi-bin/php/frameset.php PUB http://www.cig.ensmp.fr/~iahs/PUBs/PUB-proposal250602.htm HELP http://www.nwl.ac.uk/ih/help/ BAHC http://www.pik-potsdam.de/~bahc/ Check these out on the web © Oregon State University Concluding Hillslope Isotope Statements Plot Scale Hydrology Basics International journals where you will see papers that explore this © Oregon State University Concluding Isotope Statements Plot Scale Basics References - Textbooks Clark, I. and Fritz, P. 1998. Environmental Isotopes in Hydrogeology. Lewis Publisher (w/ web-link) Kendall, C. and McDonnell, J.J. (eds.), 1998. Isotope Tracers in Catchment Hydrology. Elsevier (w/ web-link) Ferronsky, V. I. And Polyakov, V. A., 1982 . Environmental Isotopes in the Hydrosphere. Wiley & Sons. Mazor, E., 1991. Applied Chemical and Isotopic Groundwater Hydrology. Open University Press. © Oregon State University Concluding Isotope Statements Plot Scale Basics References - Internet USGS Isotope Interest Group Home Page (http://wwwcamnl.wr.usgs.gov/isoig/) ISOGEOCHEM Web Page with an E-mail Discussion List in Stable Isotope Geochemistry (http://geology.uvm.edu/geowww/isogeochem.html) © Oregon State University Concluding Isotope Statements Plot Scale Basics Critical Thinking Is Inherent in Isotope Hydrology Data are scant Data are insufficient Data are wrong Hydrogeologic systems are open Mathematical solutions are inexact © Oregon State University Concluding Hillslope Isotope Statements Plot Scale Hydrology Basics Isotope Hydrology Physical Chemical Photo: Kevin McGuire Explicit solution of water and tracer mass balance © Oregon State University Isotopic Concluding Catchment Isotope Statements Plot Scale Scale Basics Day 1 Morning: Groundwater Surface Water Interaction, Hydrograph separation basics, time source separations, geographic source separations, practical issues Afternoon: Processes explaining isotope evidence, groundwater ridging, transmissivity feedback, subsurface stormflow, saturation overland flow Day 3 Morning: Introduction, Isotope Geochemistry Basics Afternoon: Isotope Geochemistry Basics ‘cont, Examples Day 2 Summary Morning: Mean residence time computation Afternoon: Stable isotopes in watershed models, mean residence time and model strcutures, two-box models with isotope time series, 3-box models and use of isotope tracers as soft data Day 4 Field Trip to Hydrohill or nearby research site © Oregon State University Concluding Isotope Statements Plot Scale Basics Why spend money on isotopes? Isotopes can be powerful tools for testing hypotheses about sources of water and solutes. While isotope analyses are not CHEAP, they can be much less expensive than being wrong. In many cases, they are more useful “fingerprints” of waters or solute sources than other physical constituents because… © Oregon State University Kendall (2001 Concluding Isotope Statements Plot Scale Isotopes are useful “fingerprints” because… Basics 1. Many isotopes are relatively conservative in reactions with matrix materials. 2. Waters of different ages, recharge zones, hydrologic/geochemical history, etc., are often isotopically very distinctive. 3. If the water from one area gets to another area, it must be hydraulically and hydrologically possible for it to get there regardless of what the models predict. © Oregon State University Kendall Concluding Hillslope Statements Plot Scale Hydrology Why Spend Money On Isotopes? Isotopes can be powerful tools for testing hypotheses about sources of waters and solutes. In many cases they are more useful “fingerprints” of waters or solute sources than other physical constituents because: 1) Many Isotopes are relatively conservative in reactions with matrix materials. 2) Waters of different ages, recharge zones, hydrologic/geochemical history, ect., are often isotopically very distinctive. 3) If the water from one area gets to another area, it must be hydraulically and hydrologically possible for it to get there, regardless of what models predict. While isotope analyses are not CHEAP, they can be much less expensive than being wrong. © Oregon State University Why Do Environmental Hydrogeologists Under-utilize Isotopes? Concluding Hillslope Statements Plot Scale Hydrology Possible Explanations: 1) Awkward terminology: one of the major obstacles to using isotopes is often the unfamiliar terminology, including: **compositions are in terms of δ (pronounced delta), not ppm. **units are 0/00 (spelled permil, per mil, or per mile. **values of isotopic compositions are often negative number. 2) Price? Not a problem. Many analyses are in the range of $50 to $150 per sample. 3) Complicated collection procedures? Not a problem: typically procedure are no more complicated than for chemical analyses. 4) Fear of the unknown. © Oregon State University Concluding Hillslope Statements Plot Scale Hydrology Fretwell’s Law “Warning! Stable isotope data may cause severe and contagious stomach upset if taken alone. To prevent upsetting reviewers’ stomachs and your own, take stable isotope data with a healthy dose of other hydrologic, geologic, and geochemical information. Then, you will find stable isotope data very beneficial.” (Marvin O. Fretwell, USGS, pers. Comm. 1983) © Oregon State University Concluding Statements Plot Scale Thankyou © Oregon State University
