Scott A Wright (Former Employee)
Science and Products
Filter Total Items: 52
Sediment budgets, transport, and depositional trends in a large tidal delta
The Sacramento-San Joaquin Delta is the largest delta on the west coast of the United States. It is formed where the confluence of California’s two largest rivers (the Sacramento and San Joaquin) meet the ocean tides and has a significant physical gradient from fluvial to tidal. It is a semidiurnal system (two high and two low tides per day). Today, the Delta is one of the most manipulated in the
Authors
Tara Morgan, Scott A. Wright
Effects of human alterations on the hydrodynamics and sediment transport in the Sacramento-San Joaquin Delta, California
The Sacramento-San Joaquin Delta, California, (Delta) has been significantly altered since the mid-nineteenth century. Many existing channels have been widened or deepened and new channels have been created for navigation and water conveyance. Tidal marshes have been drained and leveed to form islands that have subsided, some of which have permanently flooded. To understand how these alterations h
Authors
Mathieu D. Marineau, Scott A. Wright
Physically based method for measuring suspended-sediment concentration and grain size using multi-frequency arrays of acoustic-doppler profilers
As the result of a 12-year program of sediment-transport research and field testing on the Colorado River (6 stations in UT and AZ), Yampa River (2 stations in CO), Little Snake River (1 station in CO), Green River (1 station in CO and 2 stations in UT), and Rio Grande (2 stations in TX), we have developed a physically based method for measuring suspended-sediment concentration and grain size at 1
Authors
David J. Topping, Scott A. Wright, Ronald E. Griffiths, David Dean
The use of modeling and suspended sediment concentration measurements for quantifying net suspended sediment transport through a large tidally dominated inlet
Sediment exchange at large energetic inlets is often difficult to quantify due complex flows, massive amounts of water and sediment exchange, and environmental conditions limiting long-term data collection. In an effort to better quantify such exchange this study investigated the use of suspended sediment concentrations (SSC) measured at an offsite location as a surrogate for sediment exchange at
Authors
Li H. Erikson, Scott A. Wright, Edwin Elias, Daniel M. Hanes, David H. Schoellhamer, John Largier
Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century
The general progression of human land use is an initial disturbance (e.g., deforestation, mining, agricultural expansion, overgrazing, and urbanization) that creates a sediment pulse to an estuary followed by dams that reduce sediment supply. We present a conceptual model of the effects of increasing followed by decreasing sediment supply that includes four sequential regimes, which propagate down
Authors
David H. Schoellhamer, Scott A. Wright, Judith Z. Drexler
A sediment budget for the southern reach in San Francisco Bay, CA: Implications for habitat restoration
The South Bay Salt Pond Restoration Project is overseeing the restoration of about 6000 ha of former commercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m3 of sedimen
Authors
Gregory Shellenbarger, Scott A. Wright, David H. Schoellhamer
Hydraulic and Geomorphic Assessment of the Merced River and Historic Bridges in Eastern Yosemite Valley, Yosemite National Park, California: Sacramento, California
The Merced River in the popular and picturesque eastern-most part of Yosemite Valley in Yosemite National Park, California, USA, has been extensively altered since the park was first conceived in 1864. Historical human trampling of streambanks has been suggested as the cause of substantial increases in stream width, and the construction of undersized stone bridges in the 1920s has been suggested a
Authors
J. Toby Minear, Scott A. Wright
Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta
Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and mars
Authors
David H. Schoellhamer, Scott A. Wright, Judith Z. Drexler
Field evaluation of the error arising from inadequate time averaging in the standard use of depth-integrating suspended-sediment samplers
Several common methods for measuring suspended-sediment concentration in rivers in the United States use depth-integrating samplers to collect a velocity-weighted suspended-sediment sample in a subsample of a river cross section. Because depth-integrating samplers are always moving through the water column as they collect a sample, and can collect only a limited volume of water and suspended sedim
Authors
David J. Topping, David M. Rubin, Scott A. Wright, Theodore S. Melis
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization
Millions of pounds of mercury (Hg) were deposited in the river and stream channels of the Sierra Nevada from placer and hard-rock mining operations in the late 1800s and early 1900s. The resulting contaminated sediments are relatively harmless when buried and isolated from the overlying aquatic environment. The entrained Hg in the sediment constitutes a potential risk to human and ecosystem health
Authors
Jacob A. Fleck, Charles N. Alpers, Mark Marvin-DiPasquale, Roger L. Hothem, Scott A. Wright, Kevin Ellett, Elizabeth Beaulieu, Jennifer L. Agee, Evangelos Kakouros, Le H. Kieu, Dennis D. Eberl, Alex E. Blum, Jason T. May
Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine whether h
Authors
Theodore S. Melis, Paul E. Grams, Theodore A. Kennedy, Barbara E. Ralston, Christopher T. Robinson, John C. Schmidt, Lara M. Schmit, Richard A. Valdez, Scott A. Wright
Flow structures and sandbar dynamics in a canyon river during a controlled flood, Colorado River, Arizona
In canyon rivers, debris fan constrictions create rapids and downstream pools characterized by secondary flow structures that are closely linked to channel morphology. In this paper we describe detailed measurements of the three‐dimensional flow structure and sandbar dynamics of two pools along the Colorado River in the Grand Canyon during a controlled flood release from Glen Canyon Dam. Results i
Authors
Scott A. Wright, M. Kaplinski
Science and Products
Filter Total Items: 52
Sediment budgets, transport, and depositional trends in a large tidal delta
The Sacramento-San Joaquin Delta is the largest delta on the west coast of the United States. It is formed where the confluence of California’s two largest rivers (the Sacramento and San Joaquin) meet the ocean tides and has a significant physical gradient from fluvial to tidal. It is a semidiurnal system (two high and two low tides per day). Today, the Delta is one of the most manipulated in the
Authors
Tara Morgan, Scott A. Wright
Effects of human alterations on the hydrodynamics and sediment transport in the Sacramento-San Joaquin Delta, California
The Sacramento-San Joaquin Delta, California, (Delta) has been significantly altered since the mid-nineteenth century. Many existing channels have been widened or deepened and new channels have been created for navigation and water conveyance. Tidal marshes have been drained and leveed to form islands that have subsided, some of which have permanently flooded. To understand how these alterations h
Authors
Mathieu D. Marineau, Scott A. Wright
Physically based method for measuring suspended-sediment concentration and grain size using multi-frequency arrays of acoustic-doppler profilers
As the result of a 12-year program of sediment-transport research and field testing on the Colorado River (6 stations in UT and AZ), Yampa River (2 stations in CO), Little Snake River (1 station in CO), Green River (1 station in CO and 2 stations in UT), and Rio Grande (2 stations in TX), we have developed a physically based method for measuring suspended-sediment concentration and grain size at 1
Authors
David J. Topping, Scott A. Wright, Ronald E. Griffiths, David Dean
The use of modeling and suspended sediment concentration measurements for quantifying net suspended sediment transport through a large tidally dominated inlet
Sediment exchange at large energetic inlets is often difficult to quantify due complex flows, massive amounts of water and sediment exchange, and environmental conditions limiting long-term data collection. In an effort to better quantify such exchange this study investigated the use of suspended sediment concentrations (SSC) measured at an offsite location as a surrogate for sediment exchange at
Authors
Li H. Erikson, Scott A. Wright, Edwin Elias, Daniel M. Hanes, David H. Schoellhamer, John Largier
Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century
The general progression of human land use is an initial disturbance (e.g., deforestation, mining, agricultural expansion, overgrazing, and urbanization) that creates a sediment pulse to an estuary followed by dams that reduce sediment supply. We present a conceptual model of the effects of increasing followed by decreasing sediment supply that includes four sequential regimes, which propagate down
Authors
David H. Schoellhamer, Scott A. Wright, Judith Z. Drexler
A sediment budget for the southern reach in San Francisco Bay, CA: Implications for habitat restoration
The South Bay Salt Pond Restoration Project is overseeing the restoration of about 6000 ha of former commercial salt-evaporation ponds to tidal marsh and managed wetlands in the southern reach of San Francisco Bay (SFB). As a result of regional groundwater overdrafts prior to the 1970s, parts of the project area have subsided below sea-level and will require between 29 and 45 million m3 of sedimen
Authors
Gregory Shellenbarger, Scott A. Wright, David H. Schoellhamer
Hydraulic and Geomorphic Assessment of the Merced River and Historic Bridges in Eastern Yosemite Valley, Yosemite National Park, California: Sacramento, California
The Merced River in the popular and picturesque eastern-most part of Yosemite Valley in Yosemite National Park, California, USA, has been extensively altered since the park was first conceived in 1864. Historical human trampling of streambanks has been suggested as the cause of substantial increases in stream width, and the construction of undersized stone bridges in the 1920s has been suggested a
Authors
J. Toby Minear, Scott A. Wright
Conceptual model of sedimentation in the Sacramento-San Joaquin River Delta
Sedimentation in the Sacramento–San Joaquin River Delta builds the Delta landscape, creates benthic and pelagic habitat, and transports sediment-associated contaminants. Here we present a conceptual model of sedimentation that includes submodels for river supply from the watershed to the Delta, regional transport within the Delta and seaward exchange, and local sedimentation in open water and mars
Authors
David H. Schoellhamer, Scott A. Wright, Judith Z. Drexler
Field evaluation of the error arising from inadequate time averaging in the standard use of depth-integrating suspended-sediment samplers
Several common methods for measuring suspended-sediment concentration in rivers in the United States use depth-integrating samplers to collect a velocity-weighted suspended-sediment sample in a subsample of a river cross section. Because depth-integrating samplers are always moving through the water column as they collect a sample, and can collect only a limited volume of water and suspended sedim
Authors
David J. Topping, David M. Rubin, Scott A. Wright, Theodore S. Melis
The effects of sediment and mercury mobilization in the South Yuba River and Humbug Creek confluence area, Nevada County, California: Concentrations, speciation, and environmental fate – Part 1: Field characterization
Millions of pounds of mercury (Hg) were deposited in the river and stream channels of the Sierra Nevada from placer and hard-rock mining operations in the late 1800s and early 1900s. The resulting contaminated sediments are relatively harmless when buried and isolated from the overlying aquatic environment. The entrained Hg in the sediment constitutes a potential risk to human and ecosystem health
Authors
Jacob A. Fleck, Charles N. Alpers, Mark Marvin-DiPasquale, Roger L. Hothem, Scott A. Wright, Kevin Ellett, Elizabeth Beaulieu, Jennifer L. Agee, Evangelos Kakouros, Le H. Kieu, Dennis D. Eberl, Alex E. Blum, Jason T. May
Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine whether h
Authors
Theodore S. Melis, Paul E. Grams, Theodore A. Kennedy, Barbara E. Ralston, Christopher T. Robinson, John C. Schmidt, Lara M. Schmit, Richard A. Valdez, Scott A. Wright
Flow structures and sandbar dynamics in a canyon river during a controlled flood, Colorado River, Arizona
In canyon rivers, debris fan constrictions create rapids and downstream pools characterized by secondary flow structures that are closely linked to channel morphology. In this paper we describe detailed measurements of the three‐dimensional flow structure and sandbar dynamics of two pools along the Colorado River in the Grand Canyon during a controlled flood release from Glen Canyon Dam. Results i
Authors
Scott A. Wright, M. Kaplinski