Floodplain forests play many important roles in the fluvial processes and environments of large alluvial rivers, including acting as geomorphological influences and habitat for native fish during high flows. Many large, gravel-bed river systems have undergone substantial change in recent centuries, resulting in loss of forested area to agriculture, reduction...
Rainfall scarcity and variability present serious challenges to water security for many rural communities throughout the world's drylands. Sand dams--weirs built across ephemeral or seasonal rivers--provide an appropriate water harvesting and storage option for many regions. The structures quickly fill with sediment during rainy season flow events and store water...
Water temperature in rivers and streams is an important factor for aquatic ecosystem health. Measurement of stream temperature has traditionally been accomplished by point temperature measurements, continuous point temperature loggers, and more recently, airborne remote sensing techniques such as Forward-Looking Infrared Radar (FLIR) or Thermal Infrared Radiometry. While each of...
The objective of this study was to evaluate the use of aerial photos as a substitute for multiple-year pre-removal field data to assess the downstream channel changes associated with a small dam removal. The Brownsville Dam, a 2.1 m tall concrete dam on the Calapooia River, Oregon, was removed in...
The thermal regime of rivers plays a key role in aquatic ecosystem health. In the Willamette River, OR, the present day main channel temperature is often too warm for cold water fishes during the late spring, summer, and early fall. At these times, cold water fishes tend to be concentrated...
My thesis explored the effects of environmental variability on population
dynamics and community composition of aquatic insects. Environmental variability in
the form of flow regime in streams can limit the distribution and life-history traits of
aquatic insects. I used tributaries to the McKenzie River in Oregon with dramatically
different flow...
Surface water and groundwater are intimately connected by a two-way flux between the stream and the underlying aquifers; a complicated yet crucial relationship to represent in models. However, the National Water Model currently only considers a one-way flux, where groundwater can enter a stream but cannot return to the aquifer....
Excavations at the Cooper’s Ferry site (10IH73) revealed a long record of repeated human occupation extending from the late Pleistocene into the early Holocene (~16,000-10,000 cal BP) and have yielded unique insights into the Western Stemmed Tradition (WST), which includes. Several studies have focused on WST pit features encountered at...
Physical disturbance in streams has important effects on the metabolic rates of gross primary production (GPP) and ecosystem respiration (ER). Underlying lithology can control sediment size, amount, and evolution in the stream, influencing substrate stability and its effect on benthic organisms. We assessed the patterns of disturbance and recovery of...
The spatial and temporal variability of sediment transport processes in Oak Creek, OR was investigated and used to explore two study questions: 1) How do sediment transport processes influence benthic algal communities?, and 2) Can fluvial-hydraulic models make accurate predictions of bed load transport rates? Our study was conducted in...