Sediment production and delivery in Pacific Northwest
coastal streams can have damaging effects on channel
morphology and anadromous fish habitat. The research in
Pistol River was designed to determine if a link exists
between sediment delivery processes and degradation of fish
habitat. Objectives of this basin-wide analysis were to:
Dam removal is increasingly viewed as a river restoration tool because dams affect so many aspects of river hydrology, geomorphology, and ecology; but removal also has impacts. When a dam is removed, sediment accumulated over a dam’s lifetime may be transported downstream; and the timing, fate and consequences of this...
Geomorphic response to watershed disturbances commonly results in
alterations of landforms. Subsequent geomorphic recovery is dependent on the ability
of flows to entrain, transport, and organize inorganic and organic material on hillslopes
and in channels. This research analyzed changes in sediment production, channel
structure, and channel organization following disturbances in...
Geomorphic change along the lower Clackamas River is occurring at
a millennial scale due to climate change; a decadal scale as a result River
Mill Dam operation; and at an annual scale since 1996 due to a meander
cutoff. Channel response to these three mechanisms is incision.
Holocene strath terraces,...
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...
Numerous studies have explored how alluvial channel size and morphology are adjusted to different sediment and flow conditions, yet we still know very little about how and to what degree the flow regime controls channel form and processes. We use the term ‘channel form’ to refer to the size and...
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...
Channel evolution and influences of changing floodplain
characteristics, heterogenous bank materials, and altered flow regimes were
examined along the Willamette River, a large alluvial river in northwestern
Oregon. The Willamette River is composed of a series of geomorphically
diverse reaches, which have each evolved uniquely in the century following