Scott A Wright
Science and Products
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.
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
The San Antonio Reservoir is located in Alameda County, about 5 miles east of the town of Sunol. The reservoir, created in the early 1960s by the damming of San Antonio Creek, has a capacity of 50,000 acre-feet. It is owned and operated by the San Francisco Public Utilities Commission (SFPUC). The reservoir is fed by local watersheds and water from the Hetch Hetchy aqueduct.
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...
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 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. Calculation of in situ acoustic sediment attenuation using off-the-shelf horizontal ADCPs in low concentration settings
The use of “off-the-shelf” acoustic Doppler velocity profilers (ADCPs) to estimate suspended sediment concentration and grain-size in rivers requires robust methods to estimate sound attenuation by suspended sediment. Theoretical estimates of sediment attenuation require a priori knowledge of the concentration and grain-size distribution (GSD),...
Haught, Dan; Venditti, Jeremy G.; Wright, Scott A.
Bed-material characteristics of the Sacramento–San Joaquin Delta, California, 2010–13
The characteristics of bed material at selected sites within the Sacramento–San Joaquin Delta, California, during 2010–13 are described in a study conducted by the U.S. Geological Survey in cooperation with the Bureau of Reclamation. During 2010‒13, six complete sets of samples were collected. Samples were initially collected at 30 sites; however...
Marineau, Mathieu D.; Wright, Scott A. Recent advances in understanding flow dynamics and transport of water-quality constituents in the Sacramento–San Joaquin River Delta
This paper, part of the collection of research comprising the State of Bay–Delta Science 2016, describes advances during the past decade in understanding flow dynamics and how water-quality constituents move within California’s Sacramento– San Joaquin River Delta (Delta). Water-quality constituents include salinity, heat, oxygen, nutrients,...
Schoellhamer, David H.; Wright, Scott A.; Monismith, Stephen G.; Bergamaschi, Brian Long-term continuous acoustical suspended-sediment measurements in rivers – Theory, evaluation, and results from 14 stations on five rivers
We have developed a physically based method for using two acoustic frequencies to measure suspended-silt-and-clay concentration, suspended-sand concentration, and suspended-sand median grain size in river cross sections at 15-minute intervals over decadal timescales. The method is strongly grounded in the extensive scientific literature on the...
Topping, David; Wright, Scott A.; Griffiths, Ronald; Dean, David Characterizing changes in streamflow and sediment supply in the Sacramento River Basin, California, using hydrological simulation program—FORTRAN (HSPF)
A daily watershed model of the Sacramento River Basin of northern California was developed to simulate streamflow and suspended sediment transport to the San Francisco Bay-Delta. To compensate for sparse data, a unique combination of model inputs was developed, including meteorological variables, potential evapotranspiration, and parameters...
Stern, Michelle A.; Flint, Lorraine E.; Minear, Justin T.; Flint, Alan L.; Wright, Scott A.
Long-term continuous acoustical suspended-sediment measurements in rivers - Theory, application, bias, and error
It is commonly recognized that suspended-sediment concentrations in rivers can change rapidly in time and independently of water discharge during important sediment‑transporting events (for example, during floods); thus, suspended-sediment measurements at closely spaced time intervals are necessary to characterize suspended‑sediment loads. Because...
Topping, David J.; Wright, Scott A. 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)....
Morgan, Tara; Wright, Scott A.