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David H Schoellhamer

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Field observations of water and suspended-sediment fluxes at the Golden Gate were made over one ebb tide and one flood tide on three occasions: 1) 21-22 March 2016, following a large storm event that triggered the first flow into Yolo Bypass flood control structure since 2011; 2) 23 June of 2016, during a period of low freshwater inflow and 3) 27-28 February 2017, following several large storms of the wettest winter in northern California in recorded history. On each occasion, flux of water and suspended sediment were estimated using data from a boat-mounted acoustic Doppler current profiler. This instrument provided high-resolution velocity and acoustic backscatter (ABS) data at a cross-section (“transect”) near...
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Fate of Endangered Species in San Francisco Bay Tidal Marshes with Sea-Level Rise
The San Francisco Bay estuary contains the largest remaining expanse of tidal salt marshes in the western U.S. These marshes are home to a variety of federal and state protected species, such as the California clapper rail, California black rail, and the salt marsh harvest mouse. The estuary is also located on the Pacific Flyway, and is an important site for migrating and wintering birds. As climate conditions change, these salt marshes face a number of threats, including accelerated rates of sea-level rise, shifting precipitation, erosion, and more frequent and intense storms. Seas in the San Francisco Bay estuary have been rising 2.2 centimeters per decade, and could rise by as much as 1.24 meters by 2100, according...
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A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained at selected locations within the Yolo Bypass near Sacramento, California. The locations correspond to different land uses; two cores were taken at each site. The shear stress was increased in stepwise fashion, and turbidity of the effluent monitored. From this, two quantities are calculated: 1) critical shear stress required to initiate erosion, and 2) soil mass eroded per square meter at an applied shear stress of 0.4 Pa. So for each core we have a date, land use or site, core number, latitude, longitude, critical shear stress, and eroded mass at tau = 0.4 Pa.
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