Date of Award:
5-2008
Document Type:
Thesis
Degree Name:
Master of Science (MS)
Department:
Watershed Sciences
Advisor/Chair:
Michelle A Baker
Abstract
I studied nine streams near Grand Teton National Park, Wyoming, covering a land use gradient (urban, agricultural, and forested) to assess influences of land use on denitrification rates and hyporheic exchange. I hypothesized denitrification in the hyporheic zone is governed by availability of chemical substrates and hydrologic transport. I tested this hypothesis by coupling measurements of denitrification potentials in hyporheic sediments with a 2-storage zone solute transport model. Denitrification potentials were lowest on average in hyporheic sediments from forested streams and highest from agricultural streams. Modeling results suggest, on average, agricultural sites are transport-limited by having the slowest exchange rate with hyporheic zone and longest transport before entering storage. Land use influences the capacity for hyporheic denitrification in two ways 1) agricultural and urban practices supply substrates that build the microbial potential for denitrification and 2) agricultural and urban activities alter channel form and substrates, limiting hyporheic exchange.
Recommended Citation
Myers, Andrew Kenneth, "Discriminating between Biological and Hydrological Controls of Hyporheic Denitrification across a Land Use Gradient in Nine Western Wyoming Streams" (2008). All Graduate Theses and Dissertations. Paper 71.
http://digitalcommons.usu.edu/etd/71
Copyright for this work is retained by the student.