Scott A Wright
Science and Products
Sediment transport, streamflow, and climate change: long-term resilience of the Bay-Delta
Sediment supply is important to the health of the Sacramento-San Joaquin River Delta and San Francisco Bay (Bay-Delta) ecosystem. Sediment eroded from upland source areas in the Sacramento and San Joaquin watersheds is transported through the rivers to the Bay-Delta where it is deposited in mudflats and tidal wetlands, which in turn helps protect against the effects of sea-level rise. Sediment...
Sediment Acoustics
The U.S. Geological Survey recognizes the need to provide sediment acoustic training and to develop standardized techniques and practices.
Mapping Sturgeon Spawning Habitat in the Lower San Joaquin River
The spawning of adult white sturgeon (Acipenser transmontanus) in the lower San Joaquin River was documented recently by the United States Fish and Wildlife Service (USFWS) (Gruber and others, 2012; Jackson and Eenennaam, 2013). Streamflow on the San Joaquin River has been modified by State and Federal water project operations, and there are a variety of questions regarding the...
Delta sediment measurements to support numerical modeling of turbidity
The purpose of the proposed work is to collect data that will support the development, calibration, and validation of numerical models of sediment transport and turbidity in the Sacramento-San Joaquin Delta.
Geomorphic Assessment and Restoration Alternatives Development for the Merced River in East Yosemite Valley, Yosemite National Park
The National Park Service (NPS) and USGS jointly will investigate impacts to the Merced River due to infrastructure and historic channel widening in east Yosemite Valley with a goal of constructing river management alternatives. Past management actions, such as gravel mining, channel riprap, and the construction of bridges that do not accommodate flood flows, have had long-lasting impacts to...
Exploring: Reservoir Capacity And Sedimentation Of The Fena Valley Reservoir Guam
The Fena Valley Reservoir, located in southern Guam, is the primary source of water for the United States Naval Base Guam and nearby village residents. At full capacity, the reservoir surface area extends approximately 0.30 mi2, and drains a watershed area of about 5.88 mi2. After reservoir construction, periodic bathymetric surveys, coupled with sedimentation models, ...
Surrogate Monitoring of Sediment Transport using Hydrophones along the San Joaquin River and Tributaries
Traditional methods for measuring coarse bedload sediment transport by discrete physical sampling tend to be labor intensive and expensive (Gray and others, 2010). As such, bedload samples often are collected too infrequently to capture the temporal variability inherent in transport rates, which can vary significantly, sometimes by a factor of ten or more, over time periods of...
San Antonio Reservoir Bathymetric Survey and Sedimentation Study
Over time, the flow of water into the San Antonio Reservoir has caused the build-up of sediment, decreasing storage capacity. Since water storage is a crucial issue in California, up-to-date information on the reservoir is needed. To accomplish this, the San Francisco Public Utilities Commission approached the USGS California Water Science Center to conduct a bathymetric (depth) survey and...
Monitoring the Impacts of the Rim Fire on Tuolumne River Water Quality
The Rim Fire has burned over 400 square miles of the Tuolumne River and Merced River watersheds in central California and is now the 3rd largest wildfire in state history. The burn area is largely on the Tuolumne between Hetch Hetchy Reservoir and Don Pedro Reservoir, both of which serve as critical sources of drinking water and irrigation water to San Francisco Bay area and Central Valley...
Implementing New Acoustic Monitoring Techniques in the Trinity River
Accurate river-sediment data is fundamental to planning and managing river restoration efforts on the Trinity River, and throughout the world’s waterways. The USGS has developed a “hydrophone” that enables scientists to listen to sediment particles as they move along the riverbed in order to inexpensively and reliably record near-continuous sediment-bedload-transport data. For this study,...
The 'Digital Grain Size' Web and Mobile-Computing Application
This project team developed a Web-hosted application (that can also be used on mobile platforms) for automatic analysis of images of sediment for grain-size distribution, using the “Digital Grain Size” (DGS) algorithm of Buscombe (2013) (“DGS-Online,” 2015). This is a free, browser-based application for accurately estimating the grain-size distribution of sediment in digital images without...
Storage capacity and sedimentation characteristics of Loch Lomond Reservoir, California, 2019
In May of 2019, Loch Lomond Reservoir was surveyed by the U.S. Geological Survey (USGS) in cooperation with the city of Santa Cruz to assess the current storage capacity and sedimentation rates in the reservoir. Survey methods combined sonar soundings to measure bathymetry and lidar scans with GPS data to measure near-shore topography and sediment...
Whealdon-Haught, Daniel R.; Wright, Scott A.; Marineau, Mathieu D.
Self-limitation of sand storage in a bedrock-canyon river arising from the interaction of flow and grain size
Bedrock-canyon rivers tend to be supply limited because they are efficient transporters of sediment and not because the upstream supply of sediment is small. A byproduct of this supply limitation is that the finer alluvium stored in these rivers has shorter residence times and smaller volumes than in alluvial rivers. To improve our understanding...
Topping, David; Grams, Paul; Griffiths, Ronald E.; Dean, David J.; Wright, Scott A.; Unema, Joel A. Causes of variability in suspended‐sand concentration evaluated using measurements in the Colorado River in Grand Canyon
Rivers commonly exhibit substantial variability in suspended‐sand concentration, even at constant water discharge. Here we derive an approach for evaluating how much of this variability arises from mean bed‐sand grain size. We apply this approach to the Colorado River in Grand Canyon, where discharge‐independent concentration of suspended sand...
Rubin, David M.; Buscombe, Daniel; Wright, Scott A.; Topping, David; Grams, Paul; Schmidt, John C.; Hazel, J.E.; Kaplinski, Matthew A.; Tusso, Robert B. The future of sediment transport and streamflow under a changing climate and the implications for long-term resilience of the San Francisco Bay-Delta
Sedimentation and turbidity have effects on habitat suitability in the San Francisco Bay‐Delta (Bay‐Delta), concerning key species in the bay as well as the ability of the delta marshes to keep pace with sea level rise. A daily rainfall runoff and transport model of the Sacramento River Basin of northern California was developed to simulate...
Stern, Michelle A.; Flint, Lorraine E.; Flint, Alan L; Knowles, Noah; Wright, Scott A.
Storage capacity and sedimentation characteristics of the San Antonio Reservoir, California, 2018
The San Antonio Reservoir is a large water storage facility in Alameda County, California, and is a major component of the Hetch Hetchy Regional Water System (RWS). The RWS is a water-supply system owned and operated by the San Francisco Public Utilities Commission (SFPUC) and provides water for about 2.7 million people in the San Francisco, Santa...
Marineau, Mathieu D.; Wright, Scott A.; Lopez, Joan V.
Water resources on Guam—Potential impacts of and adaptive response to climate change
The goals of this joint U.S. Geological Survey, University of Hawaiʻi, University of Guam, University of Texas, and East-West Center study were to (1) provide basic understanding about water resources for U.S. Department of Defense installations on Guam and (2) assess the resulting effect of sea-level rise and a changing climate on freshwater...
Gingerich, Stephen B.; Johnson, Adam G.; Rosa, Sarah N.; Marineau, Mathieu D.; Wright, Scott A.; Hay, Lauren E.; Widlansky, Matthew J.; Jenson, John W.; Wong, Corinne I.; Banner, Jay L.; Finucane, Melissa L.; Keener, Victoria W. Field-scale sediment feed flume: Upper Santa Ana River, California
Along the San Bernardino Valley, the Santa Ana River decreases in slope, increases in width, and deposits particles from boulders to sand as it loses transport capacity. Episodic rainfalls feed very large winter floods, but dry summer and fall periods lead to extensive dry alluvial reaches due to surface water infiltration into subsurface aquifers...
Wright, Scott A.; Minear, J. Toby Refining the Baseline Sediment Budget for the Klamath River, California
Four dams in the Klamath River Hydroelectric Project (KHP) in Oregon and California (Figure 1) are currently scheduled to be removed over a period of a few weeks or months, beginning in January 2021. The Klamath dam removal will be the largest in the world by almost all measures, and is an unprecedented opportunity to advance science of river...
Anderson, Chauncey W.; Wright, Scott A.; Schenk, Liam N.; Skalak, Katherine; Curtis, Jennifer A.; East, Amy E.; Benthem, Adam Dam effects on bedload transport on the upper Santa Ana River, California, and implications for native fish habitat
Dams disrupt the flow of water and sediment and thus have the potential to affect the downstream geomorphic characteristics of a river. Though there are some well‐known and common geomorphic responses to dams, such as bed armouring, the response downstream from any particular dam is dependent on local conditions. Herein, we investigate the...
Wright, Scott A.; Minear, J Toby Turbidity current observations in a large reservoir following a major wildfire
Turbidity currents are generated when denser river water plunges and flows along the bottom of a lake, reservoir, or ocean. The plunging and downstream movement are driven by density differences due to temperature and/or suspended sediment, and currents have been observed to move slowly over long distances. This study presents observations of...
Wright, Scott A.; Marineau, Mathieu D.
Physical characteristics of the lower San Joaquin River, California, in relation to white sturgeon spawning habitat, 2011–14
The U.S. Fish and Wildlife Service confirmed that white sturgeon (Acipenser transmontanus) recently spawned in the lower San Joaquin River, California. Decreases in the San Francisco Bay estuary white sturgeon population have led to an increased effort to understand their migration behavior and habitat preferences. The preferred spawning habitat...
Marineau, Mathieu D.; Wright, Scott A.; Whealdon-Haught, Daniel R.; Kinzel, Paul J. Daily reservoir sedimentation model: Case study from the Fena Valley Reservoir, Guam
A model to compute reservoir sedimentation rates at daily timescales is presented. The model uses streamflow and sediment load data from nearby stream gauges to obtain an initial estimate of sediment yield for the reservoir’s watershed; it is then calibrated to the total deposition calculated from repeat bathymetric surveys. Long-term changes to...
Marineau, Mathieu D.; Wright, Scott A.
USGS Scientists Use Sound and Light to Measure Sediment in Water
In two recent publications, California Water Science Center scientists discuss their research using acoustic and optic technology to measure the quantity and movement of sediment in rivers and reservoirs.