|Good, Stephen - University Of Utah|
|Stalker, Jeremy - Jacksonville State University|
|Chesson, Lesley - Collaborator|
|Valenzuela, Luciano - University Of Utah|
|Beasley, Melanie - University Of California|
|Ehleringer, James - University Of Utah|
|Bowen, Gabriel - University Of Utah|
Submitted to: Water Resources Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2014
Publication Date: 10/16/2014
Citation: Good, S.P., Kennedy, C.D., Stalker, J., Chesson, L.A., Valenzuela, L.O., Beasley, M.M., Ehleringer, J.R., Bowen, G.J. 2014. Patterns of local and nonlocal water resource use across the western U.S. determined via stable isotope intercomparisons. Water Resources Research. 50:8034-8049.
Interpretive Summary: Water source identification is a priority of hydrologic, ecological, and forensic science alike. We developed a model for identifying the source of environmental and biological waters that have undergone evaporation. Results of this research offer a new model for specifying the geographic source of water samples ranging from fruit juices to human drinking water.
Technical Abstract: The stable isotope ratios of hydrogen (H) and oxygen (O) are valuable tracers of the origin of biological materials and water sources. Application of these environmental tracers is largely based on the distinct and pervasive spatial patterns of precipitation isotopes, which are preserved in many hydrological pools, animal materials, and plant products, but may be significantly influenced by post-precipitation evaporative loss. In this study, a generalizable model is developed for comparison of the H and O isotope ratios in two waters by correcting for enrichment of the heavy isotopes 2H and 18O resulting from the partial evaporation of a water sample. Five case studies are presented in which the model is used to test a range of hypothesized environmental and biological source waters. Hydrological applications showed that the model accurately predicted the origin of tap water supplies and surface water resources that had undergone evaporation. The model also predicted isotope values of store-bought citrus juices that were consistent with the purported growing region of Florida. This type of biological application can be further extended to work authenticating other types of beverages (e.g., milk, beer) in which the water commonly has undergone partial evaporation within biological or industrial processes.