Ephemeral streams with spatially and temporally variable flow are important ecological settings in semi-arid desert environments that until now have been poorly characterized. Our quantitative analysis explores how intermittent stream hydrology varies across geomorphic (mountain streams to desert washes) and climatic gradients (150-400 mm precipitation) in Southern Arizona. Stream channels were instrumented for the first time with a co-deployment of vertical profiles of subsurface temperature sensors, and electrical resistance (ER) sensors on the bed surface. HYDRUS 1-D was used to simulate vertical unsaturated flow, and differences along hydrologic, topographic, and climatic gradients were compared. Annual surface water presence varied < 1%-82% of the year, and reach-normalized infiltration water volumes were 20,000-2,500,000 m³/(km y). Surface water presence was correlated with geomorphic gradient, and infiltration volumes were correlated with surface water presence. This sensor co-deployment method has shown that ER sensors alone are necessary to estimate infiltration in semi-arid, poorly-sorted, coarse desert channels.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/238891 |
| Date | January 2012 |
| Creators | Nicholas, Hillary Dianne |
| Contributors | Meixner, Thomas, Lohse, Kathleen, Ferre, Ty |
| 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. |
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