Estuarine Processes, Hazards, and Ecosystems Active
Lifespan of marsh units in Assateague Island National Seashore and Chincoteague Bay, Maryland and Virginia
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S. Geological Survey's Woods Hole Coastal and Marine Science Center, but are collaborative projects that include participation from other U.S. Geological Survey offices, other federal and state agencies, and academic institutions.
Research
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling.
Estuaries are dynamic environments where complex interactions between the atmosphere, ocean, watershed, ecosystems, and human infrastructure take place. They serve as valuable ecological habitat and provide numerous ecosystem services and recreational opportunities. However, they are modified by physical processes such as storms and sea-level rise, while anthropogenic impacts such as nutrient loading threaten ecosystem function within estuaries. This project collects basic observational data on these processes, develops numerical models of the processes, and applies the models to understand the past, present, and future states of estuaries.
Measuring parameters such as water velocity, salinity, sediment concentration, dissolved oxygen and other constituents in watersheds, tidal wetlands, estuaries, and coasts is critical for evaluating the socioeconomic and ecological function of those regions. Technological advances have made it possible to autonomously measure these parameters over timescales of weeks to months. These measurements are necessary to evaluate three-dimensional numerical models that can represent the spatial and temporal complexity of these parameters. Once the models adequately represent relevant aspects of the physical system, they can be used to evaluate possible future scenarios including sea-level rise, streamflow changes, land-use modifications, and geomorphic evolution.
Below are other science projects associated with this project.
Estuarine Processes Model Development
Below are data releases associated with the Estuarine Processes, Hazards, and Ecosystems project.
Below are multimedia items associated with this project.
Below are publications associated with the Estuarine Processes, Hazards, and Ecosystems project.
Discontinuous hindcast simulations of estuarine bathymetric change: A case study from Suisun Bay, California
Complex mean circulation over the inner shelf south of Martha's Vineyard revealed by observations and a high-resolution model
Effect of roughness formulation on the performance of a coupled wave, hydrodynamic, and sediment transport model
Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Quantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
Mercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA
Chapter 24 Lateral variability of the estuarine turbidity maximum in a tidal strait
Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations
Constancy of the relation between floc size and density in San Francisco Bay
Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River
Estimates of suspended sediment entering San Francisco Bay from the Sacramento and San Joaquin Delta, San Francisco Bay, California
Below are data releases associated with this project.
- Overview
Estuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling. Both the spatial and temporal scales of these mechanisms are important, and therefore require modern instrumentation and state-of-the-art hydrodynamic models. These projects are led from the U.S. Geological Survey's Woods Hole Coastal and Marine Science Center, but are collaborative projects that include participation from other U.S. Geological Survey offices, other federal and state agencies, and academic institutions.
ResearchEstuarine processes, hazards, and ecosystems describes several interdisciplinary projects that aim to quantify and understand estuarine processes through observations and numerical modeling.
Estuaries are dynamic environments where complex interactions between the atmosphere, ocean, watershed, ecosystems, and human infrastructure take place. They serve as valuable ecological habitat and provide numerous ecosystem services and recreational opportunities. However, they are modified by physical processes such as storms and sea-level rise, while anthropogenic impacts such as nutrient loading threaten ecosystem function within estuaries. This project collects basic observational data on these processes, develops numerical models of the processes, and applies the models to understand the past, present, and future states of estuaries.
Measuring parameters such as water velocity, salinity, sediment concentration, dissolved oxygen and other constituents in watersheds, tidal wetlands, estuaries, and coasts is critical for evaluating the socioeconomic and ecological function of those regions. Technological advances have made it possible to autonomously measure these parameters over timescales of weeks to months. These measurements are necessary to evaluate three-dimensional numerical models that can represent the spatial and temporal complexity of these parameters. Once the models adequately represent relevant aspects of the physical system, they can be used to evaluate possible future scenarios including sea-level rise, streamflow changes, land-use modifications, and geomorphic evolution.
- Science
Below are other science projects associated with this project.
Estuarine Processes Model Development
We are developing new routines within the COAWST model framework to represent coupled bio-physical processes in estuarine and coastal regions. These include routines for marsh vulnerability to waves, estuarine biogeochemistry, and feedbacks between aquatic vegetation and hydrodynamics. - Data
Below are data releases associated with the Estuarine Processes, Hazards, and Ecosystems project.
Filter Total Items: 34No Result Found - Multimedia
Below are multimedia items associated with this project.
- Publications
Below are publications associated with the Estuarine Processes, Hazards, and Ecosystems project.
Filter Total Items: 63Discontinuous hindcast simulations of estuarine bathymetric change: A case study from Suisun Bay, California
Simulations of estuarine bathymetric change over decadal timescales require methods for idealization and reduction of forcing data and boundary conditions. Continuous simulations are hampered by computational and data limitations and results are rarely evaluated with observed bathymetric change data. Bathymetric change data for Suisun Bay, California span the 1867–1990 period with five bathymetricAuthorsNeil K. Ganju, Bruce E. Jaffe, David H. SchoellhamerComplex mean circulation over the inner shelf south of Martha's Vineyard revealed by observations and a high-resolution model
Inner-shelf circulation is governed by the interaction between tides, baroclinic forcing, winds, waves, and frictional losses; the mean circulation ultimately governs exchange between the coast and ocean. In some cases, oscillatory tidal currents interact with bathymetric features to generate a tidally rectified flow. Recent observational and modeling efforts in an overlapping domain centered on tAuthorsNeil K. Ganju, Steven J. Lentz, Anthony R. Kirincich, J. Thomas FarrarEffect of roughness formulation on the performance of a coupled wave, hydrodynamic, and sediment transport model
A variety of algorithms are available for parameterizing the hydrodynamic bottom roughness associated with grain size, saltation, bedforms, and wave–current interaction in coastal ocean models. These parameterizations give rise to spatially and temporally variable bottom-drag coefficients that ostensibly provide better representations of physical processes than uniform and constant coefficients. HAuthorsNeil K. Ganju, Christopher R. SherwoodDecadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph conAuthorsN. K. Ganju, D. H. SchoellhamerCalibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentratioAuthorsN. K. Ganju, D. H. SchoellhamerQuantifying fluxes and characterizing compositional changes of dissolved organic matter in aquatic systems in situ using combined acoustic and optical measurements
Studying the dynamics and geochemical behavior of dissolved and particulate organic material is difficult because concentration and composition may rapidly change in response to aperiodic as well as periodic physical and biological forcing. Here we describe a method useful for quantifying fluxes and analyzing dissolved organic matter (DOM) dynamics. The method uses coupled optical and acoustic meaAuthorsB.D. Downing, E. Boss, B.A. Bergamaschi, J.A. Fleck, M. A. Lionberger, N. K. Ganju, D. H. Schoellhamer, R. FujiiMercury concentrations and loads in a large river system tributary to San Francisco Bay, California, USA
In order to estimate total mercury (HgT) loads entering San Francisco Bay, USA, via the Sacramento-San Joaquin River system, unfiltered water samples were collected between January 2002 and January 2006 during high flow events and analyzed for HgT. Unfiltered HgT concentrations ranged from 3.2 to 75 ng/L and showed a strong correlation (r2 = 0.8, p < 0.001, n = 78) to suspended sediment concentratAuthorsN. David, L.J. McKee, F.J. Black, A.R. Flegal, C.H. Conaway, D. H. Schoellhamer, N. K. GanjuChapter 24 Lateral variability of the estuarine turbidity maximum in a tidal strait
The behavior of the estuarine turbidity maximum (ETM) in response to freshwater flow, tidal forcing, and bed dynamics has been studied extensively by many researchers. However, the majority of investigations focus on the longitudinal position and strength of the ETM, which can vary over tidal, spring-neap, and seasonal timescales. ETMs may become longitudinally fixed due to bathymetric constraintsAuthorsN. K. Ganju, D. H. SchoellhamerTemporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations
In this study we used hydrologic proxies to develop a daily sediment load time-series, which agrees with decadal sediment load estimates, when integrated. Hindcast simulations of bathymetric change in estuaries require daily sediment loads from major tributary rivers, to capture the episodic delivery of sediment during multi-day freshwater flow pulses. Two independent decadal sediment load estimatAuthorsN. K. Ganju, N. Knowles, D. H. SchoellhamerConstancy of the relation between floc size and density in San Francisco Bay
The size and density of fine-sediment aggregates, or flocs, govern their transport and depositional properties. While the mass and volume concentrations of flocs can be measured directly or by optical methods, they must be determined simultaneously to gain an accurate density measurement. Results are presented from a tidal cycle study in San Francisco Bay, where mass concentration was determined dAuthorsN. K. Ganju, D. H. Schoellhamer, M.C. Murrell, J. W. Gartner, S.A. WrightCorrecting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River
Discharge measurements were made by acoustic Doppler current profiler at two locations on the Colorado River during the 2004 controlled flood from Glen Canyon Dam, Arizona. Measurement hardware and software have constantly improved from the 1980s such that discharge measurements by acoustic profiling instruments are now routinely made over a wide range of hydrologic conditions. However, measuremenAuthorsJ. W. Gartner, N. K. GanjuEstimates of suspended sediment entering San Francisco Bay from the Sacramento and San Joaquin Delta, San Francisco Bay, California
This study demonstrates the use of suspended-sediment concentration (SSC) data collected at Mallard Island as a means of determining suspended-sediment load entering San Francisco Bay from the Sacramento and San Joaquin River watersheds. Optical backscatter (OBS) data were collected every 15 min during water years (WYs) 1995-2003 and converted to SSC. Daily fluvial advective sediment load was estiAuthorsL.J. McKee, N. K. Ganju, D. H. Schoellhamer - Web Tools
Below are data releases associated with this project.