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• 31. [Article] Frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon

  A first-order approximation is made of the frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon with implications for salmonid spawning ...

  Citation × Citation Citation Abstract Copy Title: Frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon Author: Fassnacht, Heidi A first-order approximation is made of the frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon with implications for salmonid spawning habitat. Field measurements of channel hydraulics, geometry, and particle size were combined with one-dimensional hydraulic and bedload transport models to determine the streamflow needed to move the channel bed material and to predict how much material would move once bedload transport was initiated. Inflows and outflows from the Dam Complex, and the predicted bedload carried by each, were compared to evaluate the effect of the Dam Complex on downstream discharge and bedload transport. Predicted critical discharges were equaled or exceeded very infrequently during the 72-year streamflow record. In addition, discharges capable of transporting bed material exceeded threshold conditions by very little. This has resulted in low predicted rates and amounts of bedload transport over the period of record. The Pelton-Round Butte Dam Complex was found to slightly increase the magnitude of flood peaks and associated predicted bedload transport for post-dam transport events exceeding threshold transport conditions. An exception to this pattern was the effect of the Dam Complex on the flood of December 1964, the second largest flood on record. This large flood occurred under unique circumstances -- while the reservoir of Round Butte Dam was filling for the first time. Since none of the transport events that occurred after the reservoir finished filling were affected by the Dam Complex in the same way as the 1964 event, the influence of the Complex on the 1964 flood is considered unique. The two largest floods on record (1964 and 1996), despite their relatively large sizes with respect to all other recorded flood events, did not cause major morphological changes to the lower Deschutes River. This observation, along with other independently derived information, supports the conclusion that the lower Deschutes is a very stable river. Title: Frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon Author: Fassnacht, Heidi A first-order approximation is made of the frequency and magnitude of bedload transport downstream of the Pelton-Round Butte Dam Complex, lower Deschutes River, Oregon with implications for salmonid spawning habitat. Field measurements of channel hydraulics, geometry, and particle size were combined with one-dimensional hydraulic and bedload transport models to determine the streamflow needed to move the channel bed material and to predict how much material would move once bedload transport was initiated. Inflows and outflows from the Dam Complex, and the predicted bedload carried by each, were compared to evaluate the effect of the Dam Complex on downstream discharge and bedload transport. Predicted critical discharges were equaled or exceeded very infrequently during the 72-year streamflow record. In addition, discharges capable of transporting bed material exceeded threshold conditions by very little. This has resulted in low predicted rates and amounts of bedload transport over the period of record. The Pelton-Round Butte Dam Complex was found to slightly increase the magnitude of flood peaks and associated predicted bedload transport for post-dam transport events exceeding threshold transport conditions. An exception to this pattern was the effect of the Dam Complex on the flood of December 1964, the second largest flood on record. This large flood occurred under unique circumstances -- while the reservoir of Round Butte Dam was filling for the first time. Since none of the transport events that occurred after the reservoir finished filling were affected by the Dam Complex in the same way as the 1964 event, the influence of the Complex on the 1964 flood is considered unique. The two largest floods on record (1964 and 1996), despite their relatively large sizes with respect to all other recorded flood events, did not cause major morphological changes to the lower Deschutes River. This observation, along with other independently derived information, supports the conclusion that the lower Deschutes is a very stable river. Close

• 32. [Article] Optimizing Reservoir Operations to Adapt to 21st Century Expectations of Climate and Social Change in the Willamette River Basin, Oregon

  Reservoir systems in the western US are managed to serve two main competing purposes: to reduce flooding during the winter and spring, and to provide water supply for multiple uses during the summer. Because ...

  Citation × Citation Citation Abstract Copy Title: Optimizing Reservoir Operations to Adapt to 21st Century Expectations of Climate and Social Change in the Willamette River Basin, Oregon Author: Moore, Kathleen M. Reservoir systems in the western US are managed to serve two main competing purposes: to reduce flooding during the winter and spring, and to provide water supply for multiple uses during the summer. Because the storage capacity of a reservoir cannot be used for both flood damage reduction and water storage at the same time, these two uses are traded off as the reservoir fills during the transition from the wet to the dry season. Climate change, population growth, and development in the western US may exacerbate dry season water scarcity and increase winter flood risk, creating a need to critically evaluate the status quo for reservoir operations. Focusing on a system of thirteen reservoirs (the Willamette Project) in the Willamette River Basin, Oregon, we estimated the values of reservoir management for reducing expected damages in the floodplain and for storing water for recreation in and around the reservoirs. We then used these values in a dynamic program to estimate the optimal fill path over the winter-spring transition period for both historical conditions and future scenarios of climate and social change. The value of stored water for summertime reservoir recreation was estimated based on the response of recreational use day counts to variation in water levels at nine of the reservoirs over the period 2001 to 2011. Visitor days were found to decline by as much as 2% per foot of drop in water level below full pool. The implied value of water to recreational users varied from $0.10 to $78 per acre-foot per month, depending on the reservoir. This range of values is comparable to prior estimates of the value of reservoir recreation in other parts of the western US, and is also similar to the value of water to irrigated agriculture in the Willamette River Basin, estimated in other studies. Because water cannot be used for recreation and irrigation at the same time, these results suggest that management of the Willamette reservoirs may benefit society by releasing stored water in summer for downstream needs from some reservoirs, while maintaining full pool for recreation in others, as prescribed currently. The expected value of flood damage reduction was estimated based on the probability of floods, flood inundation depth, and reservoir capacity, for three scenarios of future development in the Willamette River Basin, which were simulated by the Willamette Water 2100 land transition model over the period from present to 2100 using mid-range projections of future climate (MIROC5) and assumptions about future population growth. Estimates of expected flood damage reduction varied as a function of flood risk over the course of the winter and spring, as well as the rate of population growth and associated development in the floodplain. At a weekly time scale the expected benefits of flood damage reduction ranged from a high in mid-January of $304 million to $1,284 million (depending on the rate of population growth), to near zero at the end of May. Finally, these analyses were combined in a dynamic programming approach to evaluate the optimal rate of fill for the Willamette Project reservoirs, at a weekly time step over the period from January to the end of May. This was done by treating the system of thirteen reservoirs as a single reservoir. The dynamic program found the fill path that minimized the sum of flood damages and foregone recreation benefits, subject to the constraint of available water inflows to the reservoir system. The estimated optimal fill path depended on the rate of decline of expected flood damages from mid-January to May. Anticipated future increases in winter flood risk and reduced spring streamflow, associated with climate change, shifted the optimal fill path to begin earlier and to fill more slowly, compared to the optimal fill path under historical conditions. The model confirms the intuitive result that the greater the value of stored water the earlier the optimal date to begin filling. Conversely, the greater the expected value of flood damage reduction the later the initiation of fill. Despite uncertainties in the estimated values of expected flood damage reduction and stored water for recreation, as well as the limitations of the dynamic program in modelling the coordinated management of multiple reservoirs, the approach and findings of this analysis contribute to our understanding of how reservoir management may need to adapt to future changes in water supply and demand. Title: Optimizing Reservoir Operations to Adapt to 21st Century Expectations of Climate and Social Change in the Willamette River Basin, Oregon Author: Moore, Kathleen M. Reservoir systems in the western US are managed to serve two main competing purposes: to reduce flooding during the winter and spring, and to provide water supply for multiple uses during the summer. Because the storage capacity of a reservoir cannot be used for both flood damage reduction and water storage at the same time, these two uses are traded off as the reservoir fills during the transition from the wet to the dry season. Climate change, population growth, and development in the western US may exacerbate dry season water scarcity and increase winter flood risk, creating a need to critically evaluate the status quo for reservoir operations. Focusing on a system of thirteen reservoirs (the Willamette Project) in the Willamette River Basin, Oregon, we estimated the values of reservoir management for reducing expected damages in the floodplain and for storing water for recreation in and around the reservoirs. We then used these values in a dynamic program to estimate the optimal fill path over the winter-spring transition period for both historical conditions and future scenarios of climate and social change. The value of stored water for summertime reservoir recreation was estimated based on the response of recreational use day counts to variation in water levels at nine of the reservoirs over the period 2001 to 2011. Visitor days were found to decline by as much as 2% per foot of drop in water level below full pool. The implied value of water to recreational users varied from $0.10 to $78 per acre-foot per month, depending on the reservoir. This range of values is comparable to prior estimates of the value of reservoir recreation in other parts of the western US, and is also similar to the value of water to irrigated agriculture in the Willamette River Basin, estimated in other studies. Because water cannot be used for recreation and irrigation at the same time, these results suggest that management of the Willamette reservoirs may benefit society by releasing stored water in summer for downstream needs from some reservoirs, while maintaining full pool for recreation in others, as prescribed currently. The expected value of flood damage reduction was estimated based on the probability of floods, flood inundation depth, and reservoir capacity, for three scenarios of future development in the Willamette River Basin, which were simulated by the Willamette Water 2100 land transition model over the period from present to 2100 using mid-range projections of future climate (MIROC5) and assumptions about future population growth. Estimates of expected flood damage reduction varied as a function of flood risk over the course of the winter and spring, as well as the rate of population growth and associated development in the floodplain. At a weekly time scale the expected benefits of flood damage reduction ranged from a high in mid-January of $304 million to $1,284 million (depending on the rate of population growth), to near zero at the end of May. Finally, these analyses were combined in a dynamic programming approach to evaluate the optimal rate of fill for the Willamette Project reservoirs, at a weekly time step over the period from January to the end of May. This was done by treating the system of thirteen reservoirs as a single reservoir. The dynamic program found the fill path that minimized the sum of flood damages and foregone recreation benefits, subject to the constraint of available water inflows to the reservoir system. The estimated optimal fill path depended on the rate of decline of expected flood damages from mid-January to May. Anticipated future increases in winter flood risk and reduced spring streamflow, associated with climate change, shifted the optimal fill path to begin earlier and to fill more slowly, compared to the optimal fill path under historical conditions. The model confirms the intuitive result that the greater the value of stored water the earlier the optimal date to begin filling. Conversely, the greater the expected value of flood damage reduction the later the initiation of fill. Despite uncertainties in the estimated values of expected flood damage reduction and stored water for recreation, as well as the limitations of the dynamic program in modelling the coordinated management of multiple reservoirs, the approach and findings of this analysis contribute to our understanding of how reservoir management may need to adapt to future changes in water supply and demand. Close

• 33. [Article] Role of Extreme Events on Sedimentation in Loon Lake, Oregon Coast Range, USA

  Sediment cores were retrieved from a landslide-dammed lake, recording events back to the 5th century AD in a forested, mountainous catchment. These cores provide an opportunity to compare the impacts of ...

  Citation × Citation Citation Abstract Copy Title: Role of Extreme Events on Sedimentation in Loon Lake, Oregon Coast Range, USA Author: Richardson, Kristin Noel Duckworth Sediment cores were retrieved from a landslide-dammed lake, recording events back to the 5th century AD in a forested, mountainous catchment. These cores provide an opportunity to compare the impacts of known recent perturbations, including floods and timber harvesting with those of the early period of the core, flood, fire, and earthquake. A multi-parameter approach was used to measure characteristics of sediment with high-resolution grain size, %TC, %TN, and magnetic susceptibility analysis. ¹³⁷Cs atmospheric deposition and radiocarbon dating techniques were used for age control, as well as a varved record in the last 75 years. The estimated mean mass accumulation rate from 1939 to 1978 AD, the time of peak timber harvest and a cool wet phase of the Pacific Decadal Oscillation (PDO), was 0.79 (0.74-0.92) g cm⁻² y⁻¹, significantly higher than estimated mean rates of both the more recent contemporary period, 1979-2012 AD, at 0.58 (0.48-0.70) and the entire early period, 0.44 (0.41-0.46). Several event beds are coeval with estimated ages of eight Cascadia subduction zone earthquakes in the early period, including the 1700 AD Mw 9.0 earthquake. These beds are predominantly hyperpycnites, as are the known flood deposits in the contemporary period, with the exception of one debris flow within a 23-cm thick event bed deposited at approximately 700 AD. The high mass accumulation rate and high concentration of thick event beds and layers during the early contemporary period point to the extraordinary role of timber harvesting in priming the landscape for subsequent sedimentary delivery during floods. Title: Role of Extreme Events on Sedimentation in Loon Lake, Oregon Coast Range, USA Author: Richardson, Kristin Noel Duckworth Sediment cores were retrieved from a landslide-dammed lake, recording events back to the 5th century AD in a forested, mountainous catchment. These cores provide an opportunity to compare the impacts of known recent perturbations, including floods and timber harvesting with those of the early period of the core, flood, fire, and earthquake. A multi-parameter approach was used to measure characteristics of sediment with high-resolution grain size, %TC, %TN, and magnetic susceptibility analysis. ¹³⁷Cs atmospheric deposition and radiocarbon dating techniques were used for age control, as well as a varved record in the last 75 years. The estimated mean mass accumulation rate from 1939 to 1978 AD, the time of peak timber harvest and a cool wet phase of the Pacific Decadal Oscillation (PDO), was 0.79 (0.74-0.92) g cm⁻² y⁻¹, significantly higher than estimated mean rates of both the more recent contemporary period, 1979-2012 AD, at 0.58 (0.48-0.70) and the entire early period, 0.44 (0.41-0.46). Several event beds are coeval with estimated ages of eight Cascadia subduction zone earthquakes in the early period, including the 1700 AD Mw 9.0 earthquake. These beds are predominantly hyperpycnites, as are the known flood deposits in the contemporary period, with the exception of one debris flow within a 23-cm thick event bed deposited at approximately 700 AD. The high mass accumulation rate and high concentration of thick event beds and layers during the early contemporary period point to the extraordinary role of timber harvesting in priming the landscape for subsequent sedimentary delivery during floods. Close

• 34. [Article] Investigating the pore-scale mechanisms of microbial enhanced oil recovery

  This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-petr...

  Citation × Citation Citation Abstract Copy Title: Investigating the pore-scale mechanisms of microbial enhanced oil recovery Author: Armstrong, Ryan T., Wildenschild, Dorthe This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-petroleum-science-and-engineering/. Title: Investigating the pore-scale mechanisms of microbial enhanced oil recovery Author: Armstrong, Ryan T., Wildenschild, Dorthe This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/journal-of-petroleum-science-and-engineering/. Close

• 35. [Article] The Ore bin ; Vol. 28 No. 10 (October 1966)

  Fossil woods supplement knowledge of the Succor Creek fossil flora / Wallace Eubanks -- Broken Top breaks : flood released by erosion of glacial moraine / Bruce Nolf.

  Citation × Citation Citation Abstract Copy Title: The Ore bin ; Vol. 28 No. 10 (October 1966) Author: Eubanks, Wallace, Nolf, Bruce Owen, Oregon. Dept. of Geology and Mineral Industries Fossil woods supplement knowledge of the Succor Creek fossil flora / Wallace Eubanks -- Broken Top breaks : flood released by erosion of glacial moraine / Bruce Nolf. Title: The Ore bin ; Vol. 28 No. 10 (October 1966) Author: Eubanks, Wallace, Nolf, Bruce Owen, Oregon. Dept. of Geology and Mineral Industries Fossil woods supplement knowledge of the Succor Creek fossil flora / Wallace Eubanks -- Broken Top breaks : flood released by erosion of glacial moraine / Bruce Nolf. Close

• 36. [Article] Is the intensifying wave climate of the U.S. Pacific Northwest increasing flooding and erosion risk faster than sea level rise?

  This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Society of Civil Engineers and can be found at: http://ascelibrary...

  Citation × Citation Citation Abstract Copy Title: Is the intensifying wave climate of the U.S. Pacific Northwest increasing flooding and erosion risk faster than sea level rise? Author: Ruggiero, Peter This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Society of Civil Engineers and can be found at: http://ascelibrary.org/toc/jwped5/current. Title: Is the intensifying wave climate of the U.S. Pacific Northwest increasing flooding and erosion risk faster than sea level rise? Author: Ruggiero, Peter This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the American Society of Civil Engineers and can be found at: http://ascelibrary.org/toc/jwped5/current. Close

• 37. [Article] Hydrogeography of Cloudburst Flooding in the Himalaya

  Even though cloudburst events in high mountain areas can be highly destructive and result in significant losses of life, little is known definitively about these flood events. An exact understanding of ...

  Citation × Citation Citation Abstract Copy Title: Hydrogeography of Cloudburst Flooding in the Himalaya Author: Michelsen, Sonja Even though cloudburst events in high mountain areas can be highly destructive and result in significant losses of life, little is known definitively about these flood events. An exact understanding of the driving processes, typical precipitation rates, and impacts of cloudburst events remain uncertain. This study seeks to advance knowledge on the hydrology, spatial aspects, and impacts of cloudburst events through compiling a list of reported cloudburst events, investigating five case studies of cloudburst events to identify trends, and providing direction for future research. Information was collected from news articles, publications, government records, and remotely-sensed data. Major similarities across the five assessed events included occurrence during the monsoon and at night, impacted villages at elevations between 1600 and 2100 meters, lack of rainfall signatures in remotely-sensed precipitation data, occurrence of landslides with cloudburst events, catchments consisting of a majority of landslide hazard slopes, village access blockades, migrant workers as a large fatality group, and damages to hydropower. Further study on cloudburst events within larger atmospheric-landscape processes and the underlying hydrology would be helpful to plan for and respond to the flood hazards resulting from these events. Title: Hydrogeography of Cloudburst Flooding in the Himalaya Author: Michelsen, Sonja Even though cloudburst events in high mountain areas can be highly destructive and result in significant losses of life, little is known definitively about these flood events. An exact understanding of the driving processes, typical precipitation rates, and impacts of cloudburst events remain uncertain. This study seeks to advance knowledge on the hydrology, spatial aspects, and impacts of cloudburst events through compiling a list of reported cloudburst events, investigating five case studies of cloudburst events to identify trends, and providing direction for future research. Information was collected from news articles, publications, government records, and remotely-sensed data. Major similarities across the five assessed events included occurrence during the monsoon and at night, impacted villages at elevations between 1600 and 2100 meters, lack of rainfall signatures in remotely-sensed precipitation data, occurrence of landslides with cloudburst events, catchments consisting of a majority of landslide hazard slopes, village access blockades, migrant workers as a large fatality group, and damages to hydropower. Further study on cloudburst events within larger atmospheric-landscape processes and the underlying hydrology would be helpful to plan for and respond to the flood hazards resulting from these events. Close

• 38. [Article] Flood plain land usage and regulations: Salem, Eugene-Springfield urban areas

  Citation × Citation Citation Abstract Copy Title: Flood plain land usage and regulations: Salem, Eugene-Springfield urban areas Author: Humphreys, John A. Title: Flood plain land usage and regulations: Salem, Eugene-Springfield urban areas Author: Humphreys, John A. Close

• 39. [Article] Public agency to flood hazard in South Corvallis, Oregon

  Citation × Citation Citation Abstract Copy Title: Public agency to flood hazard in South Corvallis, Oregon Author: Paine, Merlyn Title: Public agency to flood hazard in South Corvallis, Oregon Author: Paine, Merlyn Close

• 40. [Article] A Culture of Resilience: Social Capital and Climate Adaptation in Post-Flood Boulder County

  2016

  Citation × Citation Citation Abstract Copy Title: A Culture of Resilience: Social Capital and Climate Adaptation in Post-Flood Boulder County Author: Shepard, Stephanie 2016 Title: A Culture of Resilience: Social Capital and Climate Adaptation in Post-Flood Boulder County Author: Shepard, Stephanie 2016 Close