Weathering releases lithogenic elements to soil and stream waters that support life in catchment ecosystems. Seasonal and inter-annual variations in hydrologic conditions change subsurface flowpaths, modifying the influence of weathering on stream waters. This study, over two climatically variable years, determined seasonal and inter-annual changes in solute sources to streams using a multi-tracer approach including major cations, strontium isotopes, germanium (Ge)/silica ratios, carbon species, and trace metals. Stream water cations display constant concentrations although discharge response was highly variable, suggesting that there is a consistent subsurface water supply. However, Sr isotope ratios, and concentrations of Ge, Fe, Al, and dissolved organic carbon, which originate from shallow soil waters, increase with the hydrograph during a wet winter snowmelt. This indicates that during a year with a thick snowpack, stream waters contain components of both shallow soilwater and groundwater during snowmelt, whereas during all other times groundwater contributes predominantly to the stream.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/265377 |
| Date | January 2012 |
| Creators | Porter, Courtney |
| Contributors | McIntosh, Jennifer, Meixner, Tom, Brooks, Paul D., Chorover, Jon, Rasmussen, Craig |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | English |
| Detected Language | English |
| Type | text, Electronic Thesis |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
Page generated in 0.0018 seconds