Andrew Stevens
Biography
EDUCATION
College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR
M.S., Oceanography, November 2004
Thesis entitled, "The impact of physical and biological properties on the erodibility of sediments along the western Adriatic Sea, Italy"
Humboldt State University, Arcata, CA
B.S., Oceanography, May 2002 (with honors)
Thesis entitled, "Surface sediment grain-size distributions of Humboldt Bay, California"
Science and Products
Estuaries and large river deltas in the Pacific Northwest
Essential habitat for wild salmon and other wildlife borders river deltas and estuaries in the Pacific Northwest. These estuaries also support industry, agriculture, and a large human population that’s expected to double by the year 2060, but each could suffer from more severe river floods, higher sea level, and storm surges caused by climate change.
Exploring the USGS Science Data Life Cycle in the Cloud
Executive Summary Traditionally in the USGS, data is processed and analyzed on local researcher computers, then moved to centralized, remote computers for preservation and publishing (ScienceBase, Pubs Warehouse). This approach requires each researcher to have the necessary hardware and software for processing and analysis, and also to bring all external data required for the workflow over the...
Sediment export and impacts associated with river delta channelization compound estuary vulnerability to sea-level rise, Skagit River Delta, Washington, USA
Improved understanding of the budget and retention of sediment in river deltas is becoming increasingly important to mitigate and plan for impacts expected with sea level rise. In this study, analyses of historical bathymetric change, sediment core stratigraphy, and modeling are used to evaluate the sediment budget and environmental response of...
Grossman, Eric E.; Stevens, Andrew W.; Dartnell, Peter; George, Doug A; Finlayson, DavidObservations of coastal change and numerical modeling of sediment-transport pathways at the mouth of the Columbia River and its adjacent littoral cell
Bathymetric and topographic surveys performed annually along the coastlines of northern Oregon and southwestern Washington documented changes in beach and nearshore morphology between 2014 and 2019. Volume change analysis revealed measurable localized erosion and deposition throughout the study area, but significant net erosion at the regional...
Stevens, Andrew W.; Elias, Edwin; Pearson, Stuart; Kaminsky, George M.; Ruggiero, Peter R; Weiner, Heather M.; Gelfenbaum, Guy R.World’s largest dam removal reverses coastal erosion
Coastal erosion outpaces land generation along many of the world’s deltas and a significant percentage of shorelines, and human-caused alterations to coastal sediment budgets can be important drivers of this erosion. For sediment-starved and erosion-prone coasts, large-scale enhancement of sediment supply may be an important, but poorly understood...
Warrick, Jonathan; Stevens, Andrew W.; Miller, Ian M.; Harrison, Shawn R; Ritchie, Andrew C.; Gelfenbaum, Guy R.Morphodynamic evolution following sediment release from the world’s largest dam removal
Sediment pulses can cause widespread, complex changes to rivers and coastal regions. Quantifying landscape response to sediment-supply changes is a long-standing problem in geomorphology, but the unanticipated nature of most sediment pulses rarely allows for detailed measurement of associated landscape processes and evolution. The intentional...
Ritchie, Andrew C.; Warrick, Jonathan; East, Amy E.; Magirl, Christopher S.; Stevens, Andrew W.; Bountry, Jennifer A.; Randle, Timothy J.; Curran, Christopher A.; Hilldale, Robert C.; Duda, Jeffrey J.; Miller, Ian M.; Pess, George R.; Eidam, Emily; Foley, Melissa M.; McCoy, Randall; Ogston, Andrea S.A regime shift in sediment export from a coastal watershed during a record wet winter, California: Implications for landscape response to hydroclimatic extremes
Small, steep watersheds are prolific sediment sources from which sediment flux is highly sensitive to climatic changes. Storm intensity and frequency are widely expected to increase during the 21st century, and so assessing the response of small, steep watersheds to extreme rainfall is essential to understanding landscape response to climate...
East, Amy E.; Stevens, Andrew W.; Ritchie, Andrew C.; Barnard, Patrick L.; Campbell‐Swarzenski, Pamela L.; Collins, Brian D.; Conaway, Christopher H.Investigation of input reduction techniques for morphodynamic modeling of complex inlets with baroclinic forcing
The Mouth of the Columbia River (MCR) is a complex estuary inlet system characterized by a buoyant plume created by high freshwater flows from the Columbia River into the Pacific Ocean. Data obtained during two major field campaigns have resulted in a comprehensive dataset of hydrodynamics and sediment transport under high (2013) and low (2005)...
Gelfenbaum, Guy R.; Elias, Edwin; Stevens, Andrew W.Increased sediment load during a large-scale dam removal changes nearshore subtidal communities
The coastal marine ecosystem near the Elwha River was altered by a massive sediment influx—over 10 million tonnes—during the staged three-year removal of two hydropower dams. We used time series of bathymetry, substrate grain size, remotely sensed turbidity, scuba dive surveys, and towed video observations collected before and during dam removal...
Rubin, Stephen P.; Miller, Ian M.; Foley, Melissa M.; Berry, Helen D.; Duda, Jeffrey J.; Hudson, Benjamin; Elder, Nancy E.; Beirne, Matthew M.; Warrick, Jonathan; McHenry, Michael L.; Stevens, Andrew W.; Eidam, Emily; Ogston, Andrea; Gelfenbaum, Guy R.; Pedersen, RobCoastal habitat and biological community response to dam removal on the Elwha River
Habitat diversity and heterogeneity play a fundamental role in structuring ecological communities. Dam emplacement and removal can fundamentally alter habitat characteristics, which in turn can affect associated biological communities. Beginning in the early 1900s, the Elwha and Glines Canyon dams in Washington, USA, withheld an estimated 30...
Foley, Melissa M.; Warrick, Jonathan A.; Ritchie, Andrew C.; Stevens, Andrew W.; Shafroth, Patrick B.; Duda, Jeffrey J.; Beirne, Matthew M.; Paradis, Rebecca; Gelfenbaum, Guy R.; McCoy, Randall; Cubley, Erin S.Digital seafloor images and sediment grain size from the mouth of the Columbia River, Oregon and Washington, 2014
Geo-referenced digital imagery of in-situ seafloor sediments in the mouth of the Columbia River was collected and analyzed to determine median grain size of the surface sediments. Digital imagery of the seafloor was collected with a “flying eyeball” (Rubin and others, 2007) from the R/V Parke Snavely from September 11 to September 13, 2014 (USGS...
Gelfenbaum, Guy R.; Carlson, Emily; Stevens, Andrew; Rubin, David M.Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, February 2016
Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented opportunity...
Stevens, Andrew; Gelfenbaum, Guy R.; Warrick, Jonathan; Miller, Ian M.; Weiner, Heather M.Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, January 2015
Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented...
Stevens, Andrew; Gelfenbaum, Guy R.; Warrick, Jonathan; Miller, Ian M.; Weiner, Heather M.Bathymetry, topography, and sediment grain-size data from the Elwha River delta, Washington, July 2015
Two dams on the Elwha River, Washington State, USA trapped over 20 million m3 of sediment, reducing downstream sediment fluxes and contributing to erosion of the river's coastal delta. The removal of the Elwha and Glines Canyon dams between 2011 and 2014 induced massive increases in river sediment supply and provided an unprecedented...
Stevens, Andrew; Gelfenbaum, Guy R.; Warrick, Jonathan; Miller, Ian M.; Weiner, Heather M.