Surface sediment transport is an important geomorphic process which can be significantly altered by management activities in forested ecosystems. Disturbance of the soil surface may result in increased sediment delivery to fish bearing streams and degradation of soil structure. Selective thinning and low impact yarding techniques were utilized in an...
Debris flow initiation is controlled by a complex interaction of geology, geomorphology, climate, and weather. In the Cascade Range of Pacific Northwest and mountainous areas globally, patterns of temperature and precipitation are being altered by climate change, which may in turn impact debris flow initiation. Temperature has increased and patterns...
The Wood River Basin lies upstream of Upper Klamath Lake, the main reservoir of the USBR Klamath Irrigation Project that provides irrigation water to 210,000 acres of downstream land. Water allocation became a contentious issue in 2001 when drought led to curtailment of irrigation deliveries to the Klamath Irrigation Project...
This study quantified the magnitude and timing of summer streamflow deficits in paired-watershed experiments in the Cascade Range of Oregon where mature and old-growth conifer forests were subjected to clearcutting, patch cutting, and overstory thinning treatments in the 1960s and 1970s. Hydrologic effects of clearcutting, small-patch cutting, and overstory thinning...
Wet meadow ecosystems are a useful natural laboratory in which to explore feedbacks between biogenic and geologic controls on valley bottom landforms. Characterized by flat valley floors flanked by higher-gradient hillslopes, these meadows are singular both in that they represent depositional features in what is primarily an erosional environment, and...
Increased water temperatures and thermal loading due to anthropogenic inputs has
been shown to negatively impact the lifecycles of aquatic organisms in riverine
systems (Poole and Berman 2001; Hannah, Malcolm et al. 2004; Quinn, Gagne et al.
2004). The studies enclosed in this thesis evaluate and quantify the heat fluxes...
Hawaiian streams are valued for environmental, cultural, and aesthetic
qualities. Windward streams in East Maui, Hawaii are diverted to irrigate crops in
central portions of the island. Diversions typically remove 100% of the base flow and
leave downstream reaches dry most of the year. Ground water seeps and springs
contribute...
This study examined how annual bedload export volume and bedload characteristics were related to disturbances including logging, floods, debris slides, and wildfires over 48 to 65-year periods in small, steep catchments in conifer forests of the western Cascade Range, Oregon. Bedload – the material rolling, sliding, or saltating along the...
Debris flows, common disturbances in many mountainous areas, initially scour or bury stream habitats; however, debris flows deliver vast amounts of wood, boulders, and gravel that may ultimately form complex stream habitat to potentially support a diverse salmonid assemblage. The materials deposited by debris flows would otherwise be inaccessible to...
Velocity measurements from drifter GPS records are assimilated and used in an ensemble-based inversion technique to extract the river bathymetry. The method is tested on a deep meandering reach and a shallow braided reach of the Kootenai River in Idaho, USA. The Regional Ocean Modeling System (ROMS) is used to...