The shallow, poorly-confined, sand and gravel aquifer underlying the lower
Malheur River basin is contaminated by nitrate and metabolites of the herbicide
dimethyl tetrachloroterephthalate (DCPA), first detected in 1983 and 1985,
respectively. The aquifer supplies water for the Ontario municipal water system,
domestic and industrial uses, and irrigation. In response...
Bedrock groundwater dynamics in headwater catchments are poorly understood and
poorly characterized. Direct hydrometric measurements have been limited due to the
logistical challenges associated with drilling through hard rock in steep, remote and
often roadless terrain. Here we develop and use an inexpensive, portable bedrock
drilling system to explore bedrock...
This study was undertaken in an attempt gain a more thorough understanding of stream/aquifer interactions on camp Creek in Central Oregon. Sections of the creek were excluded from livestock grazing between 1966 and the present. Objectives of the study were to measure the extent of the shallow aquifer in the...
Longitudinal water surface profiles from high-gradient mountain streams provide useful indicators of the relative potential for hyporheic exchange flow in stream reaches with varying morphology. The spacing between slope breaks in step-pool and pool-riffle streams provides a geomorphic scaling metric that indicates how the length of average hyporheic flow paths...
Changes in the concentrations of dissolved ammonia (NH4+1), nitrate (NO3-1), organic nitrogen (DON) were monitored along ground water flow paths to determine the importance of the ground water system to the stream nitrogen budget. The study site was located on a wide floodplain along a fourth-order
stream in the Oregon...
The specific objectives of this dissertation are to determine subsurface flow
behaviors across different antecedent wetness conditions from a top-down perspective
and to mechanistically assess the hydrological controls on DOC and N transport at the
hillslope and catchment scale. The study area is a small catchment where hillslopes
issue directly...