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
Building sandbars in the Grand Canyon
Geomorphic change in the Limitrophe reach of the Colorado River in response to the 2014 delta pulse flow, United States and Mexico
Large river bed sediment characterization with low-cost sidecan sonar: Case studies from two setting in the Colorado (Arizona) and Penobscot (Maine) Rivers
Use of flux and morphologic sediment budgets for sandbar monitoring on the Colorado River in Marble Canyon, Arizona
Characterizing riverbed sediment using high-frequency acoustics 2: scattering signatures of Colorado River bed sediment in Marble and Grand Canyons
Characterizing riverbed sediment using high-frequency acoustics 1: spectral properties of scattering
The influence of controlled floods on fine sediment storage in debris fan-affected canyons of the Colorado River basin
Monitoring and research to describe geomorphic effects of the 2011 controlled flood on the Green River in the Canyon of Lodore, Dinosaur National Monument, Colorado and Utah
Monitoring fine-sediment volume in the Colorado River ecosystem, Arizona: construction and analysis of digital elevation models
Transport of fine sediment over a coarse, immobile riverbed
The relation between invertebrate drift and two primary controls, discharge and benthic densities, in a large regulated river
A sand budget for Marble Canyon, Arizona: implications for long-term monitoring of sand storage change
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Building sandbars in the Grand Canyon
In 1963, the U.S. Department of the Interior’s Bureau of Reclamation finished building Glen Canyon Dam on the Colorado River in northern Arizona, 25 kilometers upstream from Grand Canyon National Park. The dam impounded 300 kilometers of the Colorado River, creating Lake Powell, the nation’s second largest reservoir. By 1974, scientists found that the downstream river’s alluvial sandbars were erodAuthorsPaul E. Grams, John C. Schmidt, Scott A. Wright, David Topping, Theodore S. Melis, David M. RubinGeomorphic change in the Limitrophe reach of the Colorado River in response to the 2014 delta pulse flow, United States and Mexico
A pulse of water was released from Morelos Dam into the dry streambed of the Colorado River in its former delta on March 23, 2014. Although small in relation to delta floods of a century ago, this was the first flow to reach the sea in nearly two decades. The pulse flow was significant in that it resulted from an international agreement, Minute 319, which allowed Colorado River water to be used foAuthorsErich R. Mueller, John C. Schmidt, David Topping, Paul E. GramsLarge river bed sediment characterization with low-cost sidecan sonar: Case studies from two setting in the Colorado (Arizona) and Penobscot (Maine) Rivers
Mapping subaqueous riverbed sediment grain size across channels and in nearshore areas typically used by fish and benthic invertebrates is difficult where and when the water flow is too swift or deep to wade yet impractical to access with large boats and instruments. Fluvial characteristics can further constrain sampling options, particularly where flow depth, water column turbidity or channel botAuthorsDaniel D. Buscombe, Paul E. Grams, Theodore S. Melis, Sean SmithUse of flux and morphologic sediment budgets for sandbar monitoring on the Colorado River in Marble Canyon, Arizona
The magnitude and pfattern of streamflow and sediment supply of the Colorado River in Grand Canyon (Figure 1) has been affected by the existence and operations of Glen Canyon Dam since filling of Lake Powell Reservoir began in March 1963. In the subsequent 30 years, fine sediment was scoured from the downstream channel (Topping et al., 2000; Grams et al., 2007), resulting in a decline in the numbeAuthorsPaul E. Grams, Daniel D. Buscombe, David J. Topping, Joseph E. Hazel, Matt KaplinskiCharacterizing riverbed sediment using high-frequency acoustics 2: scattering signatures of Colorado River bed sediment in Marble and Grand Canyons
In this, the second of a pair of papers on the statistical signatures of riverbed sediment in high-frequency acoustic backscatter, spatially explicit maps of the stochastic geometries (length- and amplitude-scales) of backscatter are related to patches of riverbed surfaces composed of known sediment types, as determined by geo-referenced underwater video observations. Statistics of backscatter magAuthorsDaniel D. Buscombe, Paul E. Grams, Matthew A. KaplinskiCharacterizing riverbed sediment using high-frequency acoustics 1: spectral properties of scattering
Bed-sediment classification using high-frequency hydro-acoustic instruments is challenging when sediments are spatially heterogeneous, which is often the case in rivers. The use of acoustic backscatter to classify sediments is an attractive alternative to analysis of topography because it is potentially sensitive to grain-scale roughness. Here, a new method is presented which uses high-frequency aAuthorsDaniel D. Buscombe, Paul E. Grams, Matthew A. KaplinskiThe influence of controlled floods on fine sediment storage in debris fan-affected canyons of the Colorado River basin
Prior to the construction of large dams on the Green and Colorado Rivers, annual floods aggraded sandbars in lateral flow-recirculation eddies with fine sediment scoured from the bed and delivered from upstream. Flows greater than normal dam operations may be used to mimic this process in an attempt to increase time-averaged sandbar size. These controlled floods may rebuild sandbars, but sedimentAuthorsErich R. Mueller, Paul E. Grams, John C. Schmidt, Joseph E. Hazel, Jason S. Alexander, Matt KaplinskiMonitoring and research to describe geomorphic effects of the 2011 controlled flood on the Green River in the Canyon of Lodore, Dinosaur National Monument, Colorado and Utah
In 2011, a large magnitude flow release from Flaming Gorge Reservoir, Wyoming and Utah, occurred in response to high snowpack in the middle Rocky Mountains. This was the third highest recorded discharge along the Green River downstream of Flaming Gorge Dam, Utah, since its initial closure in November 1962 and motivated a research effort to document effects of these flows on channel morphology andAuthorsErich R. Mueller, Paul E. Grams, John C. Schmidt, Joseph E. Hazel, Matt Kaplinski, Jason A. Alexander, Keith KohlMonitoring fine-sediment volume in the Colorado River ecosystem, Arizona: construction and analysis of digital elevation models
Digital elevation models (DEMs) of eleven 2–5 kilometer reaches of the Colorado River ecosystem (CRE) in Grand Canyon were constructed from repeat bathymetric and topographic surveys collected between August 2000 and December 2004. The DEMs will be used by researchers to study the effects of Glen Canyon Dam (GCD) operations on the sediment resources of the CRE in Grand Canyon by quantifying morphoAuthorsMatt Kaplinski, Joseph E. Hazel, Paul E. Grams, Philip A. DavisTransport of fine sediment over a coarse, immobile riverbed
Sediment transport in cobble-boulder rivers consists mostly of fine sediment moving over a coarse, immobile bed. Transport rate depends on several interrelated factors: boundary shear stress, the grain size and volume of fine sediment, and the configuration of fine sediment into interstitial deposits and bed forms. Existing models do not incorporate all of these factors. Approaches that partitionAuthorsPaul E. Grams, Peter R. WilcockThe relation between invertebrate drift and two primary controls, discharge and benthic densities, in a large regulated river
1. Invertebrate drift is a fundamental process in streams and rivers. Studies from laboratory experiments and small streams have identified numerous extrinsic (e.g. discharge, light intensity, water quality) and intrinsic factors (invertebrate life stage, benthic density, behaviour) that govern invertebrate drift concentrations (# m−3), but the factors that govern invertebrate drift in larger riveAuthorsTheodore A. Kennedy, Charles B. Yackulic, Wyatt F. Cross, Paul E. Grams, Michael D. Yard, Adam J. CoppA sand budget for Marble Canyon, Arizona: implications for long-term monitoring of sand storage change
Recent U.S. Geological Survey research is providing important insights into how best to monitor changes in the amount of tributary-derived sand stored on the bed of the Colorado River and in eddies in Marble Canyon, Arizona. Before the construction of Glen Canyon Dam and other dams upstream, sandbars in Glen, Marble, and Grand Canyons were replenished each year by sediment-rich floods. Sand inputAuthorsPaul E. Grams - News