College of Forestry

Watershed Processes Group

About WPG

Management of water and watersheds is emerging as one of the top natural resource issues in the Pacific Northwest and beyond. Research on effects of forest practices on water and related issues, including sediment, wood, nutrients, and water quality, has been a focal point of the USDA Pacific Northwest Research Station for over 50 years. But growing populations, threatened ecosystems, new policies, and changing expectations for water and watersheds are rapidly expanding the set of issues, questions, and research opportunities around water. Our multi-faceted research program involves a coordinated set of approaches and is directed at extending the understanding and ability to predict causes and consequences of changing streamflow regimes on stream channels and riparian ecosystems.

Mountain stream processes

Our studies of mountain stream processes are aimed at understanding how the movements of water, sediment, and wood, function in mountain landscapes to structure stream channels, riparian zones, and channel networks. These processes interact to influence frequency and magnitude of geomorphically- driven disturbances to ecosystems. This research is helping to define process-based relationships that provide a basis for predicting and mitigating cumulative effects of management activities on stream and aquatic resources, and evaluating potential effects of climate change.

Land use changes

We seek to understand how land use, including timber harvest, road construction and restoration, and woody debris management influence the rates or behavior of 'native' physical processes or introduce new processes into the landscape. Our research focuses on the linkages between hillslope and fluvial processes to determine how the effects of natural and anthropogenic disturbances are transmitted downstream to fish-bearing streams and inhabited valley bottoms. Our goal is to predict how past, present, and future land use practices influence streamflow, mass movements, sediment transport, channel morphology, and water quality.

Impacts of river regulation

Predicting the consequences of dam-imposed regimes on downstream resources is critical for managers, power companies, and all users of regulated rivers. Dams differ widely in their influence on downstream resources depending on their geologic and ecologic setting and degree to which their operation modifies pre-dam flow and sediment regimes. Increasing national interest in dam removal as a means of restoring more natural ecologic conditions in rivers motivates research about ecosystem response to dams and dam decommissioning.