David Schoellhamer (Former Employee)
Science and Products
Filter Total Items: 151
Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary
Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects
Authors
John Y. Takekawa, A.K. Miles, D. H. Schoellhamer, N.D. Athearn, M. K. Saiki, W.D. Duffy, S. Kleinschmidt, G.G. Shellenbarger, C.A. Jannusch
Estimates 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 esti
Authors
L.J. McKee, N. K. Ganju, D. H. Schoellhamer
Annual sediment flux estimates in a tidal strait using surrogate measurements
Annual suspended-sediment flux estimates through Carquinez Strait (the seaward boundary of Suisun Bay, California) are provided based on surrogate measurements for advective, dispersive, and Stokes drift flux. The surrogates are landward watershed discharge, suspended-sediment concentration at one location in the Strait, and the longitudinal salinity gradient. The first two surrogates substitute f
Authors
N. K. Ganju, D. H. Schoellhamer
Flow convergence caused by a salinity minimum in a tidal channel
Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of tidal channels can create a local reversal (change in
Authors
John C. Warner, David H. Schoellhamer, Jon R. Burau, S. Geoffrey Schladow
Napa-Sonoma marshes pond 3, hydrologic and biotic changes in a salt pond following breaching
No abstract available.
Authors
N.D. Athearn, K. Goodenough, John Y. Takekawa, A.K. Miles, M. K. Saiki, S. Spring, F. Mejia, G.G. Shellenbarger, D. H. Schoellhamer
Ecological structure of salt ponds, San Francisco Bay, California: Balancing tidal wetland restoration with existing beneficial habitat
No abstract available.
Authors
A.K. Miles, John Y. Takekawa, D. H. Schoellhamer, N.D. Athearn, M. K. Saiki, W.D. Duffy, S. Kleinschmidt, G.G. Shellenbarger, C.A. Jannusch, S.E. Spring
Estimating sediment budgets at the interface between rivers and estuaries with application to the Sacramento-San Joaquin River Delta
Where rivers encounter estuaries, a transition zone develops where riverine and tidal processes both affect sediment transport processes. One such transition zone is the Sacramento‐San Joaquin River Delta, a large, complex system where several rivers meet to form an estuary (San Francisco Bay). Herein we present the results of a detailed sediment budget for this river/estuary transitional system.
Authors
Scott A. Wright, David H. Schoellhamer
Bay sediment budget: Sediment accounting 101
Comparison of a budget developed for 1955-1990 with a budget developed for 1995- 2002 showed decreasing sediment inflow and increased amounts leaving the Bay to upland disposal and sand mining, resulting in an increased rate of erosion of sediment from the Bay floor
Finding a way to shift disposal from the Ocean back to the Bay could provide sediment for restoration projects and decrease dredging
Authors
David H. Schoellhamer, Megan A. Lionberger, Bruce E. Jaffe, Neil K. Ganju, Scott A. Wright, Gregory Shellenbarger
Suspended sediment fluxes in a tidal wetland: Measurement, controlling factors, and error analysis
Suspended sediment fluxes to and from tidal wetlands are of increasing concern because of habitat restoration efforts, wetland sustainability as sea level rises, and potential contaminant accumulation. We measured water and sediment fluxes through two channels on Browns Island, at the landward end of San Francisco Bay, United States, to determine the factors that control sediment fluxes on and off
Authors
N. K. Ganju, D. H. Schoellhamer, B.A. Bergamaschi
Salt-Pond Box Model (SPOOM) and Its Application to the Napa-Sonoma Salt Ponds, San Francisco Bay, California
A box model to simulate water volume and salinity of a salt pond has been developed by the U.S. Geological Survey to obtain water and salinity budgets. The model, SPOOM, uses the principle of conservation of mass to calculate daily pond volume and salinity and includes a salt crystallization and dissolution algorithm. Model inputs include precipitation, evaporation, infiltration, and water transfe
Authors
Megan L. Lionberger, David H. Schoellhamer, Paul A. Buchanan, Scott Meyer
Trends in the sediment yield of the Sacramento River, California, 1957-2001
Human activities within a watershed, such as agriculture, urbanization, and dam building, may affect the sediment yield from the watershed. Because the equilibrium geomorphic form of an estuary is dependent in part on the sediment supply from the watershed, anthropogenic activities within the watershed have the potential to affect estuary geomorphology. The Sacramento River drains the northern hal
Authors
Scott A. Wright, David H. Schoellhamer
Floodtide pulses after low tides in shallow subembayments adjacent to deep channels
In shallow waters surface gravity waves (tides) propagate with a speed proportional to the square root of water depth (c=g(h+η)). As the ratio of free surface displacement to mean depth (η/h) approaches unity the wave will travel noticeably faster at high tide than at low tide, creating asymmetries in the tidal form. This physical process is explained analytically by the increased significance of
Authors
J.C. Warner, D. H. Schoellhamer, C.A. Ruhl, J.R. Burau
Science and Products
- Science
- Data
- Publications
Filter Total Items: 151
Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary
Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projectsAuthorsJohn Y. Takekawa, A.K. Miles, D. H. Schoellhamer, N.D. Athearn, M. K. Saiki, W.D. Duffy, S. Kleinschmidt, G.G. Shellenbarger, C.A. JannuschEstimates 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. SchoellhamerAnnual sediment flux estimates in a tidal strait using surrogate measurements
Annual suspended-sediment flux estimates through Carquinez Strait (the seaward boundary of Suisun Bay, California) are provided based on surrogate measurements for advective, dispersive, and Stokes drift flux. The surrogates are landward watershed discharge, suspended-sediment concentration at one location in the Strait, and the longitudinal salinity gradient. The first two surrogates substitute fAuthorsN. K. Ganju, D. H. SchoellhamerFlow convergence caused by a salinity minimum in a tidal channel
Residence times of dissolved substances and sedimentation rates in tidal channels are affected by residual (tidally averaged) circulation patterns. One influence on these circulation patterns is the longitudinal density gradient. In most estuaries the longitudinal density gradient typically maintains a constant direction. However, a junction of tidal channels can create a local reversal (change inAuthorsJohn C. Warner, David H. Schoellhamer, Jon R. Burau, S. Geoffrey SchladowNapa-Sonoma marshes pond 3, hydrologic and biotic changes in a salt pond following breaching
No abstract available.AuthorsN.D. Athearn, K. Goodenough, John Y. Takekawa, A.K. Miles, M. K. Saiki, S. Spring, F. Mejia, G.G. Shellenbarger, D. H. SchoellhamerEcological structure of salt ponds, San Francisco Bay, California: Balancing tidal wetland restoration with existing beneficial habitat
No abstract available.AuthorsA.K. Miles, John Y. Takekawa, D. H. Schoellhamer, N.D. Athearn, M. K. Saiki, W.D. Duffy, S. Kleinschmidt, G.G. Shellenbarger, C.A. Jannusch, S.E. SpringEstimating sediment budgets at the interface between rivers and estuaries with application to the Sacramento-San Joaquin River Delta
Where rivers encounter estuaries, a transition zone develops where riverine and tidal processes both affect sediment transport processes. One such transition zone is the Sacramento‐San Joaquin River Delta, a large, complex system where several rivers meet to form an estuary (San Francisco Bay). Herein we present the results of a detailed sediment budget for this river/estuary transitional system.AuthorsScott A. Wright, David H. SchoellhamerBay sediment budget: Sediment accounting 101
Comparison of a budget developed for 1955-1990 with a budget developed for 1995- 2002 showed decreasing sediment inflow and increased amounts leaving the Bay to upland disposal and sand mining, resulting in an increased rate of erosion of sediment from the Bay floor Finding a way to shift disposal from the Ocean back to the Bay could provide sediment for restoration projects and decrease dredgingAuthorsDavid H. Schoellhamer, Megan A. Lionberger, Bruce E. Jaffe, Neil K. Ganju, Scott A. Wright, Gregory ShellenbargerSuspended sediment fluxes in a tidal wetland: Measurement, controlling factors, and error analysis
Suspended sediment fluxes to and from tidal wetlands are of increasing concern because of habitat restoration efforts, wetland sustainability as sea level rises, and potential contaminant accumulation. We measured water and sediment fluxes through two channels on Browns Island, at the landward end of San Francisco Bay, United States, to determine the factors that control sediment fluxes on and offAuthorsN. K. Ganju, D. H. Schoellhamer, B.A. BergamaschiSalt-Pond Box Model (SPOOM) and Its Application to the Napa-Sonoma Salt Ponds, San Francisco Bay, California
A box model to simulate water volume and salinity of a salt pond has been developed by the U.S. Geological Survey to obtain water and salinity budgets. The model, SPOOM, uses the principle of conservation of mass to calculate daily pond volume and salinity and includes a salt crystallization and dissolution algorithm. Model inputs include precipitation, evaporation, infiltration, and water transfeAuthorsMegan L. Lionberger, David H. Schoellhamer, Paul A. Buchanan, Scott MeyerTrends in the sediment yield of the Sacramento River, California, 1957-2001
Human activities within a watershed, such as agriculture, urbanization, and dam building, may affect the sediment yield from the watershed. Because the equilibrium geomorphic form of an estuary is dependent in part on the sediment supply from the watershed, anthropogenic activities within the watershed have the potential to affect estuary geomorphology. The Sacramento River drains the northern halAuthorsScott A. Wright, David H. SchoellhamerFloodtide pulses after low tides in shallow subembayments adjacent to deep channels
In shallow waters surface gravity waves (tides) propagate with a speed proportional to the square root of water depth (c=g(h+η)). As the ratio of free surface displacement to mean depth (η/h) approaches unity the wave will travel noticeably faster at high tide than at low tide, creating asymmetries in the tidal form. This physical process is explained analytically by the increased significance ofAuthorsJ.C. Warner, D. H. Schoellhamer, C.A. Ruhl, J.R. Burau