Natural stream systems contain a variety of flow geometries which contain flow separation, turbulent shear layers, and recirculation zones. This work focuses on streams with dead zones. Characterized by slower flow and recirculation, dead zones are naturally occurring cutouts in stream banks. These dead zones play an important role in...
Elevated groundwater nitrate (NO3
-) concentrations in the Southern Willamette
Valley (SWV) caused the Oregon Department of Environmental Quality (ODEQ) to
declare a Groundwater Management Area (GWMA) in Spring, 2004. To better
understand direction of groundwater flow, groundwater age, and nitrate transport
pathways of the SWV we developed a steady-state...
Hyporheic Exchange Flow (HEF) is driven by head gradients defined by the hydro-topography of the stream surface, which is controlled by the particular geomorphology of the stream. We quantified the impact of large wood, which typically exerts a strong control on stream morphology, on HEF in a second order, low...
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Roy D. Haggerty
Hyporheic Exchange Flow (HEF) is driven by head gradients defined by the
Mass transfer processes were evaluated in an artificial, non-uniform porous medium with a power law distribution of diffusion rate coefficients obtained from physical characterization of solute and porous medium. Breakthrough curves of several pulse experiments conducted at different velocities were compared (1) to analytical expressions for concentrations at mass transfer...
An ASR metric and site rating index applied to over 120 municipal and agricultural locations across Oregon, combined with comparison to case study data from existing ASR sites, indicate that more than 50% of selected sites are hydrogeologically suitable for ASR. The ASR metric is a ratio of aquifer storage...
Stream chemistry studies conducted in the forested Watershed 1 of the HJ Andrews Experimental Forest show a contribution of CO2 from the hyporheic zone. Hyporheic CO₂ concentrations, measured as pCO₂, have a seasonal trend as well as a responsiveness to storm events. Concentrations are highest at the end of the...
Water temperature is an essential property of a stream. Temperature regulates
physical and biochemical processes in aquatic habitats. Various factors related to
climatic conditions, landscape characteristics, and channel structure directly influence
stream temperature. Numerous studies indicate that increased average air temperature
during the past century has led to stream warming...
The relationship between carbon burial and sedimentation in reservoirs is unknown, exposing gaps in our fundamental understanding of the transport, processing, and deposition of sediment and organic matter in fluvial and lacustrine systems and contributing to uncertainty in our understanding of the net impact of dams to the global carbon...