We examined the relationships between large wood (LW) export and precipitation patterns and intensity by analyzing the data on the annual volume of LW removed from 42 reservoirs and the daily precipitation at or near the reservoir sites. We also calculated the effective precipitation by considering the antecedent precipitation. Both...
Mountain rivers are important aquatic ecosystems that regulate sediment and water delivery to higher order streams. While previous studies have debated the roles of hillslope and fluvial processes in driving change in channel morphology of mountain rivers, few have examined how these processes influence channel response over longer timescales. The...
Although there has been extensive research on the geomorphic and ecologic role of
large woody debris (LWD) in streams, the dynamics of LWD in streams are poorly
known due to various measurement difficulties during floods. In this thesis I present the
results of two flume experiments on the dynamics of...
There is still scholarly debate on the impacts of large floods on the geomorphic evolution of mountain rivers. Understating the geomorphic effects of large flows in mountain rivers is challenging given the hydraulic complexity of these systems and the inherent unpredictability of large floods. Prior work has demonstrated that extreme...
Although dam construction has been an integral tool in development initiatives for nearly a century, dams can have significant negative impacts on local residents, particularly those who are permanently displaced from their homes and must be resettled elsewhere. Dams have unique impacts on indigenous peoples. As a result, many dam...
The re-introduction of large woody debris (LWD) into streams and rivers for stream restoration purposes is rapidly growing. Engineered log jams (ELJs) are man-made structures intended to mimic natural LWD structures, designed and installed to protect stream banks from erosion while increasing habitat diversity. Several studies have evaluated the flow...
Uneven-aged management has been suggested as a method for balancing biodiversity conservation and wood production goals from managed forests in a variety of regions. In coastal Douglas-fir (Pseudotsuga menziesii) forests of the Pacific Northwest, implementation of uneven-aged management is hindered by a lack of experience with uneven-aged silvicultural systems, including...
The West Eugene Wetlands, Eugene, Oregon, which provide habitat for number of endemic and endangered plant species, are currently threatened by a Reed canarygrass (Phalaris arundinacea L.) invasion. This study addresses the hypothesis that Phalaris spread can be explained in part by using watershed-scale landuse patterns as surrogates of the...
Simulations of stream-subsurface water exchange (hyporheic exchange) using a three-dimensional steady state groundwater flow model and a particle tracking model in unconstrained and constrained reaches of small (2nd-order) and intermediate (5th-order) mountain streams were conducted to estimate the effects of geomorphic features on the extent, volume and residence time of...
Forests are highly valuable resources providing both timber as well as many non-use values like habitat for various endangered and threatened species, carbon sequestration, and recreation, to name a few. Given that there are 765 million acres of forestland in the United States, almost 60% of which are privately owned,...