|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 - Purdue University
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: Identifying the source of drinking water is a priority of hydrologic, ecological, and forensic science alike. We sought to characterize regional patterns in human drinking (tap) water sources from cities across the US using signature patterns in stable water isotopes. Results of this research offer a new model for determining the source of tap waters.
Technical Abstract: In this paper we develop an isotope-based statistical framework to evaluate the dynamics of the relationship between water supplies used for human consumption and several hydrological factors, including the spatiotemporal distribution of precipitation and snowmelt as well as the timing and rates of evaporation, based on a 2-yr-long monthly survey of the hydrogen and oxygen stable isotope'''2H and '18O) composition of human drinking water within the U.S. and southern Canada. We demonstrate that tap water '2H and '18O values, analyzed in the context of estimated distributions of water isotopes in precipitation, reflect important processes linking tap water supplies with their ultimate meteoric water sources, including the use of water derived from non-local precipitation and evaporative water loss. Based on these results, we propose two “isotopic indices” to identify and characterize the regional extent of evaporative losses and hydrologic connectivity between water supplies and the local precipitation source. We quantify uncertainty in the isotopic indices and demonstrate potential applications of these indices including regional assessment of source-supply connectivity. We propose that the isotopic indices represent a tool for research and monitoring efforts at regional to continental scales and, advancing in parallel with recent work aimed at developing predictive frameworks for tap water isotopes, offer an approach for evaluating the origin of water in hydrological, ecological, and forensic investigations.