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Maureen Downing-Kunz

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Lower South Bay (LSB), a shallow subembayment of San Francisco Bay (SFB), is situated south of the Dumbarton Bridge, and is surrounded by, and interconnected with, a network of sloughs, marshes, and former salt ponds undergoing restoration (Figure ES.1). LSB receives 120 million gallons per day of treated wastewater effluent from three publicly owned treatment works (POTWs) that service San Jose and the densely populated surrounding region. During the dry season, when flows from creeks and streams are at their minimum, POTW effluent comprises the majority of freshwater flow to Lower South Bay. Although LSB has a large tidal prism, it experiences limited net exchange with the surrounding Bay, because much of the...
Categories: Publication; Types: Citation
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The San Francisco estuary is commonly defined to include San Francisco Bay (bay) and the adjacent Sacramento–San Joaquin River Delta (delta). The U.S. Geological Survey (USGS) has operated a high-frequency (15-minute sampling interval) water-quality monitoring network in San Francisco Bay since the late 1980s (Buchanan and others, 2014). This network includes 19 stations at which sustained measurements have been made in the bay; currently, 8 stations are in operation (fig. 1). All eight stations are equipped with specific conductance (which can be related to salinity) and water-temperature sensors. Water quality in the bay constantly changes as ocean tides force seawater in and out of the bay, and river inflows—the...
Categories: Publication; Types: Citation; Tags: Open-File Report
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Measurements of suspended sediment concentration, water velocity, suspended-sediment particle size, and suspended-sediment particle settling velocity were collected to estimate suspended-sediment flux and investigate sediment transport processes at Dumbarton Bridge in San Francisco Bay (NWIS station 373015122071000) from calendar year 2018 to 2019. Data were collected using: stationary and boat-mounted acoustic Doppler current meters (ADCP, a 1 MHz Nortek Aquadopp and a 1200kHz Teledyne RiverPro, respectively), four stationary and one profiling multiparameter water quality profiling sondes (YSI 6920), a stationary acoustic backscattering sensor (ABS, Sequoia LISST-ABS), a stationary laser diffraction particle size...
A Gust erosion chamber was used to apply horizontal shear stress to sediment cores obtained from San Pablo and Grizzly (within Suisun) Bays in California. A pair of sediment cores were collected from the same approximate locations in each bay six times between June 12th, 2019 and August 15th, 2019 for a total of 12 experiments and 24 sediment core results. Locations were chosen to capture the benthic variability along the estuarine salinity gradient, are established benthic monitoring stations, proximity to historic/restored wetlands, and practicality for field operations. Sampling dates targeted spring and neap tide conditions. An onshore experiment was conducted on each core to apply shear stresses with stepwise...
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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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