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Influence of hyporheic flow and geomorphology on temperature of a large, gravel-bed river, Clackamas River, Oregon, USA

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dc.contributor.advisor Grant, Gordon
dc.contributor.advisor Haggerty, Roy
dc.creator Burkholder, Barbara K.
dc.date.accessioned 2008-01-22T18:35:16Z
dc.date.available 2008-01-22T18:35:16Z
dc.date.copyright 2007-11-26
dc.date.issued 2008-01-22T18:35:16Z
dc.identifier.uri http://hdl.handle.net/1957/7607
dc.description Graduation date: 2008
dc.description Archival zip files must be uncompressed before use. Files can be uncompressed using any tool that supports the zip compression format (like WinZip, Windows XP+, Mac OS X+, gzip, etc.) Once uncompressed, run the included html page to initiate the active content.
dc.description.abstract The hyporheic zone influences the thermal regime of rivers, buffering temperature by storing and releasing heat over a range of timescales. We examined the relationship between hyporheic exchange and temperature along a 24-km reach of the lower Clackamas River, a large gravel-bed river in northwestern Oregon (median discharge = 75.7 m³/s; minimum mean monthly discharge = 22.7 m³/s in August 2006). With a simple mixing model, we estimated how much hyporheic exchange cools the river during hot summer months. Hyporheic exchange was primarily identified by temperature anomalies, which are patches of water that demonstrate at least a 1 °C temperature difference from the main channel. Forty hyporheic temperature anomalies were identified through field investigations and TIR (Thermal-Infrared-Radiometry) in summer 2006. The location of anomalies was associated with specific geomorphic features, primarily bar channels and bar heads that act as preferential pathways for hyporheic flow. Detailed field characterization and groundwater modeling on three Clackamas gravel bars indicate residence times of hyporheic water can vary from hours to weeks and months. This was largely determined by hydraulic conductivity, which is affected by how recently the gravel bar formed or was reworked. Upscaling of modeled discharges and hydrologic parameters from these bars to the other anomalies on the Clackamas network shows that hyporheic discharge from anomalies comprises a small fraction (<< 1 %) of mainstem discharge, resulting in small river cooling effects (0.012 °C). However, the presence of cooler patches of water within rivers can act as thermal refugia for fish and other aquatic organisms, making the creation or enhancement of hyporheic exchange an attractive method in restoring the thermal regime of rivers. en
dc.format.extent 5629285 bytes
dc.format.extent 32159227 bytes
dc.format.mimetype application/pdf
dc.format.mimetype application/zip
dc.language.iso en_US en
dc.relation Explorer Site -- Oregon Explorer en
dc.subject hyporheic exchange en
dc.subject river temperature en
dc.subject gravel bars en
dc.subject geomorphology en
dc.subject.lcsh Hyporheic zones -- Oregon -- Clackamas River en
dc.subject.lcsh Water temperature -- Oregon -- Clackamas River en
dc.subject.lcsh Fluvial geomorphology -- Oregon -- Clackamas River en
dc.subject.lcsh Bars (Geomorphology) -- Oregon -- Clackamas River en
dc.title Influence of hyporheic flow and geomorphology on temperature of a large, gravel-bed river, Clackamas River, Oregon, USA en
dc.type Thesis en
dc.degree.name Master of Science (M.S.) in Water Resources Science en
dc.degree.level Master's en
dc.degree.discipline Science en
dc.degree.grantor Oregon State University en
dc.contributor.committeemember Khangaonkar, Tarang
dc.contributor.committeemember Wampler, Peter
dc.contributor.committeemember Bailey, John


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