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School of Environment and Natural Resources


SENR Seminar Series- Rachel Gabor

Sep 6, 2018, 4:00pm - 5:30pm
103 Kottman Hall

Rachel Gabor, SENR Assistant Professor of Watershed Hydrology, will present Sewersheds and Watersheds: Natural and Anthropogenic Drivers of Hydrology as Water Quality Controls in Urbanized Mountain Streams on Thursday, September 6th, 2018 at 4:10P.M. in 103 Kottman Hall.

Listen to the recording of Rachel's presentation here:


Growing populations and environmental change place stresses on hydrologic systems and alter water quality.  Understanding the interplay of natural and human-engineered processes within our watersheds is necessary to predict the future of our water resources and to develop sustainable management strategies.  The interplay of hydrology and biogeochemistry can be used to understand watershed controls on water quality and impacts of disturbance events, such as land cover change, on watershed functioning. 

Urbanization adds a layer of complexity to the hydrologic functioning of watersheds, but does not completely overwrite natural hydrologic behavior.  We characterized hydrologic controls on water quality along the mountain-to-urban transition in watersheds found in Utah’s Wasatch Front.  Using a variety of hydrologic and chemical measurements we were able to identify how the hydrology controls the biogeochemical functioning of the watersheds. Significant urban impacts to water quality do not appear until several kilometers into the urban environment, where there is evidence of an urban-contaminated alluvial aquifer feeding the stream baseflow.  At this location the substantial increase in chloride and nitrate concentrations corresponds to an increase in the C:N of the dissolved organic matter (DOM), suggesting dissolved organic arbon (DOC) in the subsurface is utilized for microbial denitrification of urban nitrate inputs. There is also a shift in DOM chemistry, as measured by fluorescence, with the mountain DOM having a greater aromaticity than the urban DOM, and opposite seasonal patterns in DOM chemical character. This suggests a shift in biogeochemical functioning in the subsurface due to urban land use, which in turn influences surface water quality.