Paul Grams, Ph.D.
Paul Grams is a geomorphologist at the Southwest Biological Science Center's field station, Grand Canyon Monitoring and Research Center. He manages a set of projects collectively called the River Geomorphology and Geomorphic Change project. These include a range of studies that describe, quantify, and predict geomorphic change, mostly on large rivers in the western United States.&nb
Paul Grams received a BA in Geology from Middlebury College (1991), an M.S. in Geology from Utah State University (1997), and a Ph.D. in Geography and Environmental Engineering from Johns Hopkins University (2006). For an undergraduate thesis, Paul examined the effects of Hells Canyon Dam on the hydrology and downstream physical resources of the Snake River in Idaho. Since that time he has studied the interaction between human-induced changes in hydrology and channel form on many segments of the Green River in Utah and Colorado, small streams in northern Utah and southern Idaho, and the Colorado River in Grand Canyon. Paul’s current research interests are in fluvial geomorphology, sediment transport, the downstream effects of dams and diversions, and the connections between physical processes and ecological systems on large rivers. Paul is currently a research hydrologist at the Grand Canyon Monitoring and Research Center and manages several projects related to geomorphology, sediment budgets, and the effects of controlled floods on the Colorado River in Grand Canyon and in other parts of the Colorado River Basin.
Science and Products
Filter Total Items: 22
No Result Found
Filter Total Items: 76
Associations between riparian plant morphological guilds and fluvial sediment dynamics along the regulated Colorado River in Grand Canyon
Effects of riparian vegetation on fluvial sediment dynamics depend on morphological traits of the constituent species. Determining the effects of different morphological guilds on sedimentation rates, as influenced by multiple aspects of dam operations, can help identify viable strategies for streamflow and vegetation management to achieve riparian resource goals. Plants of increasing size and bra
Authors
Bradley J. Butterfield, Paul Grams, Laura E. Durning, Joseph Hazel, Emily C. Palmquist, Barbara Ralston, Joel B. Sankey
Estimating bedload from suspended load and water discharge in sand bed rivers
Estimates of fluvial sediment discharge from in situ instruments are an important component of large‐scale sediment budgets that track long‐term geomorphic change. Suspended sediment load can be reliably estimated using acoustic or physical sampling techniques; however, bedload is difficult to measure directly and can consequently be one of the largest sources of uncertainty in estimates of total
Authors
T.C. Ashley, B. McElroy, D. Buscombe, Paul Grams, M. Kaplinski
Using oblique imagery to measure hypsometric changes in sandbar volume following controlled floods in the Grand Canyon
Measuring changes in the elevation distribution of sub-aerial fine (< 2 mm ) sediment and estimating sandbar volume multiple times per year can improve sediment budget calculations in fluvial systems. In the Grand Canyon of the Colorado River, effects of dam operations on sandbar size and distribution is of long-term management interest. Bar-building controlled floods have been implemented in 1996
Authors
Ryan Lima, Daniel Buscombe, Temuulen T. Sankey, Paul Grams, Erich R. Mueller
Sandbar deposition caused by high-flow experiments on the Colorado River downstream from Glen Canyon Dam: November 2012 – November 2018
The streamflow regime and sand supply of the Colorado River have been affected by the presence and operations of Glen Canyon Dam since filling of Lake Powell began in March 1963. Consequent changes in river morphology have included decreases in the size and abundance of sandbars used as campsites in Grand Canyon National Park (Dolan and others, 1974; Schmidt and Graf, 1990; Kearsley and others, 19
Authors
Paul Grams
Optimal timing of high-flow experiments for sandbar deposition
Sediment-transport theory and field measurements indicate that the greatest or most efficient deposition of sand in eddies occurs during controlled floods (a.k.a. High-Flow Experiments or HFEs) when the greatest amount of the finest sand is available on the bed of the Colorado River (Topping and others, 2010). Conducting HFEs when the sand on the bed of the Colorado River is depleted and coarse ca
Authors
David Topping, Paul E. Grams, Ronald E. Griffiths, Joseph E. Hazel, Matthew Kaplinski, David Dean, Nicholas Voichick, Joel Unema, Thomas A. Sabol
Probabilistic substrate classification with multispectral acoustic backscatter: A comparison of discriminative and generative models
We propose a probabilistic graphical model for discriminative substrate characterization, to support geological and biological habitat mapping in aquatic environments. The model, called a fully-connected conditional random field (CRF), is demonstrated using multispectral and monospectral acoustic backscatter from heterogeneous seafloors in Patricia Bay, British Columbia, and Bedford Basin, Nova Sc
Authors
Daniel Buscombe, Paul E. Grams
Quantifying and forecasting changes in the areal extent of river valley sediment in response to altered hydrology and land cover
In river valleys, sediment moves between active river channels, near-channel deposits including bars and floodplains, and upland environments such as terraces and aeolian dunefields. Sediment availability is a prerequisite for the sustained transfer of material between these areas, and for the eco-geomorphic functioning of river networks in general. However, the difficulty of monitoring sediment a
Authors
Alan Kasprak, Joel B. Sankey, Daniel Buscombe, Joshua Caster, Amy E. East, Paul E. Grams
Long-term evolution of sand transport through a river network: Relative influences of a dam versus natural changes in grain size from sand waves
Temporal and spatial nonuniformity in supplies of water and sand in a river network leads to sand transport that is in local disequilibrium with the upstream sand supply. In such river networks, sand is transported downstream as elongating waves in which coupled changes in grain size and transport occur. Depending on the magnitude of each sand‐supplying event and the interval between such events,
Authors
David Topping, Erich R. Mueller, John C. Schmidt, Ronald E. Griffiths, David Dean, Paul E. Grams
Quantifying geomorphic and vegetation change at sandbar campsites in response to flow regulation and controlled floods, Grand Canyon National Park, Arizona
Sandbars along the Colorado River in Grand Canyon National Park, USA, are an important recreational resource used as campsites by over 25,000 river runners and hikers annually. The number and size of campsites decreased following the completion of Glen Canyon Dam in 1963 due to reductions of sediment that replenish sandbars and increases in vegetation cover caused by flow regulation. Campsite area
Authors
Daniel R. Hadley, Paul E. Grams, Matthew A. Kaplinski
How many measurements are required to construct an accurate sand budget in a large river? Insights from analyses of signal and noise
Morphological change in river channels is frequently evaluated in the context of mass balance sediment budgets. In a closed sediment budget, measurements of sediment influx and efflux are coupled with measured changes in channel topography to provide both spatial and temporal resolution, and independent estimates of the mass balance. For sediment budgets constructed over long river segments (~10 c
Authors
Paul Grams, Daniel D. Buscombe, David Topping, Matthew Kaplinski, Joseph Hazel
Probabilistic models of seafloor composition using multispectral acoustic backscatter: The benthic detectorists
We describe and compare two probabilistic models
for task-specific seafloor characterization based on multispectral
backscatter. We examine whether generative or discriminative
approaches to supervised seafloor characterization do better
at harnessing the greatly increased information about seafloor
substrate composition that is encoded in the backscattering
response across multiple frequencies. A
Authors
Daniel Buscombe, Paul E. Grams, Matthew Kaplinski
Geomorphology and vegetation change at Colorado River campsites, Marble and Grand Canyons, Arizona
Sandbars along the Colorado River are used as campsites by river runners and hikers and are an important recreational resource within Grand Canyon National Park, Arizona. Regulation of the flow of river water through Glen Canyon Dam has reduced the amount of sediment available to be deposited as sandbars, has reduced the magnitude and frequency of flooding events, and has increased the magnitude o
Authors
Daniel R. Hadley, Paul E. Grams, Matthew A. Kaplinski, Joseph E. Hazel, Roderic A. Parnell
Science and Products
Filter Total Items: 22
No Result Found
Filter Total Items: 76
Associations between riparian plant morphological guilds and fluvial sediment dynamics along the regulated Colorado River in Grand Canyon
Effects of riparian vegetation on fluvial sediment dynamics depend on morphological traits of the constituent species. Determining the effects of different morphological guilds on sedimentation rates, as influenced by multiple aspects of dam operations, can help identify viable strategies for streamflow and vegetation management to achieve riparian resource goals. Plants of increasing size and bra
Authors
Bradley J. Butterfield, Paul Grams, Laura E. Durning, Joseph Hazel, Emily C. Palmquist, Barbara Ralston, Joel B. Sankey
Estimating bedload from suspended load and water discharge in sand bed rivers
Estimates of fluvial sediment discharge from in situ instruments are an important component of large‐scale sediment budgets that track long‐term geomorphic change. Suspended sediment load can be reliably estimated using acoustic or physical sampling techniques; however, bedload is difficult to measure directly and can consequently be one of the largest sources of uncertainty in estimates of total
Authors
T.C. Ashley, B. McElroy, D. Buscombe, Paul Grams, M. Kaplinski
Using oblique imagery to measure hypsometric changes in sandbar volume following controlled floods in the Grand Canyon
Measuring changes in the elevation distribution of sub-aerial fine (< 2 mm ) sediment and estimating sandbar volume multiple times per year can improve sediment budget calculations in fluvial systems. In the Grand Canyon of the Colorado River, effects of dam operations on sandbar size and distribution is of long-term management interest. Bar-building controlled floods have been implemented in 1996
Authors
Ryan Lima, Daniel Buscombe, Temuulen T. Sankey, Paul Grams, Erich R. Mueller
Sandbar deposition caused by high-flow experiments on the Colorado River downstream from Glen Canyon Dam: November 2012 – November 2018
The streamflow regime and sand supply of the Colorado River have been affected by the presence and operations of Glen Canyon Dam since filling of Lake Powell began in March 1963. Consequent changes in river morphology have included decreases in the size and abundance of sandbars used as campsites in Grand Canyon National Park (Dolan and others, 1974; Schmidt and Graf, 1990; Kearsley and others, 19
Authors
Paul Grams
Optimal timing of high-flow experiments for sandbar deposition
Sediment-transport theory and field measurements indicate that the greatest or most efficient deposition of sand in eddies occurs during controlled floods (a.k.a. High-Flow Experiments or HFEs) when the greatest amount of the finest sand is available on the bed of the Colorado River (Topping and others, 2010). Conducting HFEs when the sand on the bed of the Colorado River is depleted and coarse ca
Authors
David Topping, Paul E. Grams, Ronald E. Griffiths, Joseph E. Hazel, Matthew Kaplinski, David Dean, Nicholas Voichick, Joel Unema, Thomas A. Sabol
Probabilistic substrate classification with multispectral acoustic backscatter: A comparison of discriminative and generative models
We propose a probabilistic graphical model for discriminative substrate characterization, to support geological and biological habitat mapping in aquatic environments. The model, called a fully-connected conditional random field (CRF), is demonstrated using multispectral and monospectral acoustic backscatter from heterogeneous seafloors in Patricia Bay, British Columbia, and Bedford Basin, Nova Sc
Authors
Daniel Buscombe, Paul E. Grams
Quantifying and forecasting changes in the areal extent of river valley sediment in response to altered hydrology and land cover
In river valleys, sediment moves between active river channels, near-channel deposits including bars and floodplains, and upland environments such as terraces and aeolian dunefields. Sediment availability is a prerequisite for the sustained transfer of material between these areas, and for the eco-geomorphic functioning of river networks in general. However, the difficulty of monitoring sediment a
Authors
Alan Kasprak, Joel B. Sankey, Daniel Buscombe, Joshua Caster, Amy E. East, Paul E. Grams
Long-term evolution of sand transport through a river network: Relative influences of a dam versus natural changes in grain size from sand waves
Temporal and spatial nonuniformity in supplies of water and sand in a river network leads to sand transport that is in local disequilibrium with the upstream sand supply. In such river networks, sand is transported downstream as elongating waves in which coupled changes in grain size and transport occur. Depending on the magnitude of each sand‐supplying event and the interval between such events,
Authors
David Topping, Erich R. Mueller, John C. Schmidt, Ronald E. Griffiths, David Dean, Paul E. Grams
Quantifying geomorphic and vegetation change at sandbar campsites in response to flow regulation and controlled floods, Grand Canyon National Park, Arizona
Sandbars along the Colorado River in Grand Canyon National Park, USA, are an important recreational resource used as campsites by over 25,000 river runners and hikers annually. The number and size of campsites decreased following the completion of Glen Canyon Dam in 1963 due to reductions of sediment that replenish sandbars and increases in vegetation cover caused by flow regulation. Campsite area
Authors
Daniel R. Hadley, Paul E. Grams, Matthew A. Kaplinski
How many measurements are required to construct an accurate sand budget in a large river? Insights from analyses of signal and noise
Morphological change in river channels is frequently evaluated in the context of mass balance sediment budgets. In a closed sediment budget, measurements of sediment influx and efflux are coupled with measured changes in channel topography to provide both spatial and temporal resolution, and independent estimates of the mass balance. For sediment budgets constructed over long river segments (~10 c
Authors
Paul Grams, Daniel D. Buscombe, David Topping, Matthew Kaplinski, Joseph Hazel
Probabilistic models of seafloor composition using multispectral acoustic backscatter: The benthic detectorists
We describe and compare two probabilistic models
for task-specific seafloor characterization based on multispectral
backscatter. We examine whether generative or discriminative
approaches to supervised seafloor characterization do better
at harnessing the greatly increased information about seafloor
substrate composition that is encoded in the backscattering
response across multiple frequencies. A
Authors
Daniel Buscombe, Paul E. Grams, Matthew Kaplinski
Geomorphology and vegetation change at Colorado River campsites, Marble and Grand Canyons, Arizona
Sandbars along the Colorado River are used as campsites by river runners and hikers and are an important recreational resource within Grand Canyon National Park, Arizona. Regulation of the flow of river water through Glen Canyon Dam has reduced the amount of sediment available to be deposited as sandbars, has reduced the magnitude and frequency of flooding events, and has increased the magnitude o
Authors
Daniel R. Hadley, Paul E. Grams, Matthew A. Kaplinski, Joseph E. Hazel, Roderic A. Parnell