A large, damaging earthquake in 1944 on a blind thrust fault caused 60 cm of surface rupture on the subsidiary La Laja fault and additional unmeasured growth of an associated backlimb fold. Both the fold and fault are components of the La Laja Fault System (LLFS) located 25 km northeast...
The use of Native American fire regimes evolved in the Klamath-Siskiyou bioregion over millennia. A mixture of Native American and Euro-American socio-cultural management has developed from adaptations to climate, topography, ecological processes, and land use practices. This research incorporates Traditional Ecological Knowledge (TEK) to partially examine the role of tribal...
I used current water management practices in central and eastern Oregon and Washington as natural experiments to quantify the effects of irrigation water withdrawals on macroinvertebrate community structure and life history strategies. Reduced discharge had direct (e.g. decreased velocity and wetted habitat) and indirect (e.g. increased conductivity and temperature) effects...
Several reports related to dams and dam removal have been released this decade by non-governmental organizations including Dam Removal: Science and Decision Making by The Heinz Center which focused on small dams, since most of the dams removed to date as well as those likely to be removed in the...
This study examines stream channel erosion processes in a small urbanizing watershed influenced by deposits of the Columbia Basin catastrophic floods: Kelley Creek, a 12-km² tributary of Johnson Creek, located just east of Portland, Oregon. Information on landscape history, stream channels, and sediment dynamics was compiled. The effects of future...
The Middle Fork of the John Day River (MFJD) in Northeastern Oregon contains important spawning grounds for spring Chinook and summer steelhead of the Columbia River Basin. In the summer of 2008 phase one of a river restoration project was completed which included the addition of engineered log jams (ELJs)...
Streamflow patterns are a result of the interaction of many factors, including climate, vegetation, geology, and topography. Analyses indicate that streamflow patterns have changed around the United States over the past century, raising questions about the possible role of climate variability as a driver of water yield. This thesis examines...
Bar-pool morphology in rivers can provide vital habitat to aquatic species, notably salmonids, which require gravel riffles to bury eggs and pools for hydraulic and cold-water refuge. In some cases, the erosion and subsequent deposition of coarse sediment downstream of a dam removal can modify habitat by inundating bar-pool structure,...
Floods are major disturbance events for riverine ecosystems, directly and indirectly impacting organisms and their habitat. In this study I investigated the role of riverine floods and flow alteration in regulating aquatic macroinvertebrate population and community structure. I examined this problem using a variety of methods: a meta-analytic review of...
Dams and reservoirs are important components of water resource management systems, but their operational sensitivity to streamflow variability may make them vulnerable to climate change. Climate change is likely to affect the magnitude and timing of streamflow, motivating the assessment of potential impacts on dams and reservoirs. Here I examine...
I conducted a study to identify potential spawning habitat for anadromous salmonids above a 60-year-old hydropower dam in the headwaters of the North Umpqua River in Oregon. Like many other historical salmonid-bearing rivers, little documentation exists for anadromous fish presence above potential natural obstacles upstream of Soda Springs Dam. My...
This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
Many applications in computer graphics and geometry processing rely on the ability to
locally orient 2D and 3D entities on a surface, or inside a volume, such as the sinusoidal
kernels in Gabor noise, the color and geometry textures in pattern synthesis, and the
finite elements in remeshing. In these...
Large wood (LW) pieces are recognized as an important habitat component for salmon freshwater habitat. As such, they are often used in stream habitat restoration practices despite a lack of knowledge about their impacts on spatial and temporal hydraulic characteristics relevant to fish habitat. In this thesis we present results...
Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives simultaneously. There are various sources of uncertainty associated with the reservoir operation problem that should be considered as well.
The overarching goal...
This work is a compilation of problems that deal with multiscale analysis of transport phenomena in environmental systems. A common feature among the problems studied here is the presence of non-negligible microscale structure in various forms. Each problem is approached from the perspective that a macroscopic observable encodes aspects of...
The Willamette River Basin supports 70% of Oregon’s population and contains the richest native fish fauna in the state, (Hulse, Gregory, & Baker, 2002). The Basin is facing changes that stress its water management regimes. Is the Basin’s water management regime able to adapt in the face of these changes?...
Migration and spawning phenology of Pacific Salmon is linked to the hydroregime, and thought to be triggered by increases in river discharge and decreases in water temperature. However, little data exists that describes direct fine-scale linkages between the hydroregime and spawning in Coho Salmon. This study evaluated the spatial and...
The West Coast salmon fishery presents several complexities that have received little attention in the fisheries economics literature. Two of those complexities are reviewed and analyzed in this dissertation. The first, salmon fishermen participate in alternative fisheries within a season demonstrating a complex switching behavior between different species. Second, the...
With the increasing international focus on transboundary cooperation as a part of the Sustainable Development Goal (SDG) Framework, there is global recognition of transboundary water cooperation as a tool for improved governance and management of transboundary surface and groundwaters. Yet, there is not an agreed upon definition of transboundary water...