Drag and sediment transport: conditions at the bottom boundary
Science Center Objects
Research on bed sediment grain size, bedform morphology, vegetation characteristics, and sediment resuspension and transport is part of the Sediment Transport in Coastal Environments project.
USGS physical scientist Cordell Johnson, at left, and USGS research oceanographer Jessie Lacy, both from the Pacific Coastal and Marine Science Center, guide a tripod with instruments into the waters of the Mokelumne River where it meets the San Joaquin River. The Mokelumne is part of the vast Sacramento-San Joaquin River Delta in California, located east of San Francisco Bay and south of Sacramento.
(Credit: John Koster, USGS)
This research is part of the project Sediment Transport in Coastal Environments.
Objectives
Investigate the influence of seafloor properties, including bed sediment grain size, bedform morphology, and vegetation characteristics, on sediment resuspension and transport.
Develop parameterizations of the influence of seafloor properties on sediment transport for inclusion in numerical models.
Investigate the temporal variability of bed sediment grain size on event and seasonal time scales, and investigate the response of bedform morphology to changes in bed sediment grain size.
Collaborate with Team members in collecting oceanographic and sediment transport data to advance understanding of coastal ecosystems and coastal hazards.
Pete Dal Ferro and Andrew Stevens, both from the USGS Pacific Coastal and Marine Science Center (PCMSC) in Santa Cruz, California, install a Vaisala WXT weather station in Grizzly Bay, east of San Pablo Bay and northeast of San Francisco. The weather station collects wind speed, temperature, air pressure, relative humidity, and rainfall, and data are transmitted to a web page in real time via a custom-built data logger and modem designed by PCMSC oceanographer Dan Nowacki. Other sensors installed in Grizzly and San Pablo Bays, collecting wave and current speed, water temperature, salinity, pressure, and more, can be used with data from this weather station to help gain a better understanding of the conditions that influence sediment movement through the Bays.
The weather station is installed on this structure which is called a "dolphin," in the middle of Grizzly Bay. Obviously, someone (not us!) long ago thought it woud be funny to install a "pedestrian crossing" sign!
(Credit: Sam McGill, USGS. Public domain.)
The weather station gets its power from a small solar panel. Data collected from the station is transmitted via a wireless modem.
(Credit: Pete Dal Ferro, USGS. Public domain.)
The dolphin in Grizzly Bay with the USGS weather station installed on top. We will use the data from the weather station in conjunction with other oceanographic data, in our studies of sediment movement in the bay.
(Credit: Pete Dal Ferro, USGS. Public domain.)
Sediment Transport in Coastal Environments
Our research goals are to provide the scientific information, knowledge, and tools required to ensure that decisions about land and resource use, management practices, and future development in the coastal zone and adjacent watersheds can be evaluated with a complete understanding of the probable effects on coastal ecosystems and communities, and a full assessment of their vulnerability to...
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Date published: August 17, 2020Status: ActiveSediment transport between estuarine habitats in San Francisco Bay
This research is part of the project “Sediment Transport in Coastal Environments”
Contacts: Jessie Lacy -
Date published: July 27, 2020Status: ActiveCoastal watershed and estuary restoration in the Monterey Bay area
This research is part of the project “Sediment Transport in Coastal Environments”
Contacts: Amy EastAttribution: Pacific Coastal and Marine Science Center -
Date published: July 14, 2020Status: ActiveSan Francisco Bay geomorphology
This research is part of the project “Sediment Transport in Coastal Environments”
Contacts: Bruce Jaffe -
Date published: June 4, 2020Status: ActiveDrag and sediment transport: conditions at the bottom boundary
Research on bed sediment grain size, bedform morphology, vegetation characteristics, and sediment resuspension and transport is part of the Sediment Transport in Coastal Environments project.
Contacts: Jessie Lacy -
Date published: May 22, 2020Status: ActiveSediment transport in submarine canyons
This research is part of the project “Sediment Transport in Coastal Environments”
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Date published: December 9, 2019Status: ActiveTransport of invasive microorganisms
This research is part of the project “Sediment Transport in Coastal Environments”
Contacts: Mary McGann -
Date published: July 15, 2019Status: ActiveColumbia River estuary
This research is part of the project “Sediment Transport in Coastal Environments”
Contacts: Guy GelfenbaumAttribution: Pacific Coastal and Marine Science Center -
Date published: December 6, 2018Status: CompletedEcosystem Engineers: Impacts of Invasive Aquatic Vegetation on the Delta’s Critical Ecosystems
The Sacramento-San Joaquin Delta (Delta) is home to a diverse community of plants and animals and is the hub of California’s freshwater delivery system. The Delta supplies water for over 25 million Californians and supports millions of acres of farming, commercial and sport fishing, shipping and ports, and recreational boating.
Contacts: Judith Z Drexler, Jessie Lacy, David Schoellhamer, Maureen Downing-Kunz, Paul Work, Ph.D., P.E., D.CE, Dr. Shruti Khanna
Bed shear stress estimation under wave conditions using near-bottom measurements: Comparison of methods
Understanding the influence of waves on bed shear stress is critical for predicting morphodynamical behaviours in coastal areas. Near-bed flow was measured on the middle and lower intertidal mudflats along the Jiangsu coast, China, using a three-dimensional acoustic velocimeter that collected a 3.5-cm vertical profile at 1mm resolution and sample...
Zhang, Qian; Gong, Zheng; Zhang, Changkuan; Lacy, Jessica R.; Jaffe, Bruce E.; Xu, Beibei Model-based interpretation of sediment concentration and vertical flux measurements in a shallow estuarine environment
A one-dimensional numerical model describing tidally varying vertical mixing and settling was used to interpret sediment concentrations and vertical fluxes observed in the shoals of South San Francisco Bay by two acoustic Doppler velocimeters (ADVs) at elevations of 0.36 m and 0.72 m above bed. Measured sediment concentrations changed by up to 100...
Brand, Andreas; Lacy, Jessica R.; Gladding, Steve; Holleman, Rusty; Stacey, Mark T. Lateral baroclinic forcing enhances sediment transport from shallows to channel in an estuary
We investigate the dynamics governing exchange of sediment between estuarine shallows and the channel based on field measurements at eight stations spanning the interface between the channel and the extensive eastern shoals of South San Francisco Bay. The study site is characterized by longitudinally homogeneous bathymetry and a straight channel,...
Lacy, Jessica R.; Gladding, Steve; Brand, Andreas; Collignon, Audric; Stacey, Mark T. Autonomous bed-sediment imaging-systems for revealing temporal variability of grain size
We describe a remotely operated video microscope system, designed to provide high-resolution images of seabed sediments. Two versions were developed, which differ in how they raise the camera from the seabed. The first used hydraulics and the second used the energy associated with wave orbital motion. Images were analyzed using automated frequency...
Buscombe, Daniel; Rubin, David M.; Lacy, Jessica R.; Storlazzi, Curt D.; Hatcher, Gerald; Chezar, Henry; Wyland, Robert; Sherwood, Christopher R. Interactions between waves, sediment, and turbulence on a shallow estuarine mudflat
Measurements were collected on a shallow estuarine mudflat in northern San Francisco Bay to examine the physical processes controlling waves, turbulence, sediment resuspension, and their interactions. Tides alone forced weak to moderate currents of 10–30 cm s-1 in depths of 0–3 m, and maintained a background suspension of 30–50 mg L21 of fine...
MacVean, Lissa J.; Lacy, Jessica R. Currents, drag, and sediment transport induced by a tsunami
We report observations of water surface elevation, currents, and suspended sediment concentration (SSC) from a 10-m deep site on the inner shelf in northern Monterey Bay during the arrival of the 2010 Chile tsunami. Velocity profiles were measured from 3.5 m above the bed (mab) to the surface at 2 min intervals, and from 0.1 to 0.7 mab at 1 Hz....
Lacy, Jessica R.; Rubin, David M.; Buscombe, Daniel The influence of wave energy and sediment transport on seagrass distribution
A coupled hydrodynamic and sediment transport model (Delft3D) was used to simulate the water levels, waves, and currents associated with a seagrass (Zostera marina) landscape along a 4-km stretch of coast in Puget Sound, WA, USA. A hydroacoustic survey of seagrass percent cover and nearshore bathymetry was conducted, and sediment grain size was...
Stevens, Andrew W.; Lacy, Jessica R. Wind-enhanced resuspension in the shallow waters of South San Francisco Bay: Mechanisms and potential implications for cohesive sediment transport
We investigated the driving forces of sediment dynamics at the shoals in South San Francisco Bay. Two stations were deployed along a line perpendicular to a 14 m deep channel, 1000 and 2000 m from the middle of the channel. Station depths were 2.59 and 2.19 m below mean lower low water, respectively. We used acoustic Doppler velocimeters for the...
Brand, Andreas; Lacy, Jessica R.; Hsu, Kevin; Hoover, Daniel; Gladding, Steve; Stacey, Mark T. Interaction of lateral baroclinic forcing and turbulence in an estuary
Observations of density and velocity in a channel in northern San Francisco Bay show that the onset of vertical density stratification during flood tides is controlled by the balance between the cross-channel baroclinic pressure gradient and vertical mixing due to turbulence. Profiles of velocity, salinity, temperature, and suspended sediment...
Lacy, J.R.; Stacey, M.T.; Burau, J.R.; Monismith, Stephen G.-
Date published: July 5, 2020Bed sediment properties in Little Holland Tract and Liberty Island, Sacramento-San Joaquin Delta, California, 2014 to 2019 (ver. 2.0, May 2020)
Bed sediments were collected in two submerged agricultural tracts. Samples were analyzed for grain size distribution, bulk density, or both, from multiple locations during surveys from 2014-2019. This effort was part of a large study to investigate how shallow water habitats in the Delta function and whether they provide good habitat for native fish species, including the Delta smelt.
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Date published: May 18, 2020Sediment transport and aquatic vegetation data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018
We measured currents, suspended-sediment concentration, bed sediment characteristics, and vegetation biomass density in the Sacramento-San Joaquin Delta in 2017-2018, as part of a project investigating the influence of invasive aquatic vegetation on flow and sediment flux. This data release includes data from three sites: Lindsey Slough, Middle River, and lower Mokelumne River.
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Date published: January 1, 2019Hydrodynamic and sediment transport data from San Pablo Bay (northern San Francisco Bay), 2011-2012
The U.S. Geological Survey Pacific Coastal and Marine Science Center collected data to investigate sediment dynamics in the shallows of San Pablo Bay in two deployments: February to March 2011 (ITX11) and May to June 2012 (ITX12). This data release includes time-series data and grain-size distributions from sediment grabs collected during the deployments. During each deployment, time
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Date published: December 26, 2017Hydrodynamic and sediment transport data from San Pablo Bay and China Camp marsh (northern San Francisco Bay), 2013-2016
The USGS Pacific Coastal and Marine Science Center collected data to investigate sediment dynamics in the shallows of San Pablo Bay (SP) and sediment exchange between bay shallows and the tidal salt marsh in China Camp State Park (CMC) in a series of deployments between December 2013 and June 2016. This data release includes two related groups of data sets, one for SP and one for CMC.
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Date published: December 21, 2016Wind-wave and suspended-sediment data from Liberty Island and Little Holland Tract, Sacramento-San Joaquin Delta, California
Investigate the influence of wind waves on sediment dynamics in two flooded agricultural tracts. Part of a large interdisciplinary study led by the USGS and funded by the U.S. Bureau of Reclamation to investigate how shallow-water habitats in the Sacramento-San Joaquin Delta function and whether they provide good habitat for native fish species, including the Delta smelt.
Weather station power supply and modem
A weather station, installed in the middle of Grizzly Bay east of San Pablo Bay (near San Francisco), gets its power from a small solar panel. Data collected from the station is transmitted via a wireless modem. Far in the background is the city of Benicia, and the plume rising into the sky is water vapor emitted from the Benicia oil refinery.
Grizzly Bay dolphin with weather station installed on top
A structure called a dolphin, permanently affixed in the sediment, stands in Grizzly Bay near San Francisco, CA, with a weather station installed on top. The USGS will use the data from the weather station in conjunction with other oceanographic data, in their studies of sediment movement in the bay.
Installing weather station in Grizzly Bay
Pete Dal Ferro and Andrew Stevens, both from the USGS Pacific Coastal and Marine Science Center (PCMSC) in Santa Cruz, California, install a Vaisala WXT weather station in Grizzly Bay, east of San Pablo Bay and northeast of San Francisco. The weather station collects wind speed, temperature, air pressure, relative humidity, and rainfall, and data are transmitted to a web
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PCMSC research vessel Parke Snavely departs for deployment
The PCMSC research vessel R/V Parke Snavely heads out of the Vallejo Marina on June 11, 2019 to deploy instrument frames in Grizzly Bay for the ERO19 study.
Tripod preparation for ERO19
Lukas Winkler-Prins checks on the frame setup on June 10, 2019. This tripod has an RBR CTD, an RBR bursting pressure sensor, an RBR optical backscatter sensor, a LISST-200X, an altimeter, and two Nortek ADVs + Seapoint optical backscatter sensors, which will reveal information about water temperature and salinity, wave height and period, total suspended sediment
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Date published: August 31, 2018Are Invasive Plants Trapping the Sediment that a Healthy Estuary Needs? Sweating the Small Stuff in California’s Sacramento-San Joaquin River Delta
In recent years, invasive aquatic plants have increased exponentially in the shallow waters of California’s Sacramento-San Joaquin River Delta, clogging about 17,400 acres (nearly 30 square miles) of the waterways. Among the plants’ many effects are changes in the way mud and sand move through the region.