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Neil K. Ganju

Publications and source records attributed to Neil K. Ganju.

97 records · Page 6Linked to original sources
USGS2005

Summary of suspended-sediment concentration data, San Francisco Bay, California, Water Year 2003

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2003 (October 1, 2002-September 30, 2003). Optical sensors and water samples were used to monitor suspended-sediment concentration at two sites in Suisun Bay, three sites in San Pablo Bay, one site in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the output of the optical sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes the suspended-sediment concentration data collected from October 2002 through September 2003. Calibration curves and plots of edited data for each sensor also are presented.

Data Series↗
USGS2005

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 costs Increased erosion of the Bay is mobilizing legacy contaminants from the sediment bed Restoration projects could increase erosion and mobilization of legacy contaminants Sand mining, ignored in previous budgets, removes almost twice as much sediment from the Bay as dredging

California↗
USGS2004

Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2002

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2002 (October 1, 2001-September 30, 2002). Optical backscatterance sensors and water samples were used to monitor suspended sediment at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes the suspended-sediment concentration data collected from October 2001 through September 2002. Calibration curves and plots of edited data for each sensor also are presented.

Open-File Report↗
USGS2003

Summary of Suspended-Sediment Concentration Data, San Francisco Bay, California, Water Year 2001

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2001 (October 1, 2000-September 30, 2001). Optical backscatterance sensors and water samples were used to monitor suspended sediment at two sites in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors so that a record of suspended-sediment concentrations could be derived. This report presents the data-collection methods used and summarizes the suspended-sediment concentration data collected from October 2000 through September 2001. Calibration curves and plots of edited data for each sensor also are presented.

Open-File Report↗
USGS2003

Sediment dynamics drive contaminant dynamics

Many contaminants of greatest concern in San Francisco Bay, including mercury and PCBs, are primarily associated with sediment particles rather than dissolved in water. Therefore, the movement and fate of sediment determines the movement and fate of many contaminants in the Bay. Because of this close association, the RMP monitors and seeks to understand the quantity and movement of sediment suspended in the water. Through study of suspended sediment dynamics, the RMP is developing a better understanding of trends and patterns of contaminants and how the Bay will respond to management actions during the next several decades. Recent RMP efforts to develop predictive models of contaminant fate in the Bay have highlighted the fundamental importance of understanding sediment dynamics. Sediment movement in the Bay is determined by tides, wind, and freshwater inflow. Tides flood and ebb twice a day, wind typically is strongest in the afternoon, and freshwater inflow is greatest during the winter rainy season (see sidebar on next page). To characterize these fluctuations, the U.S. Geological Survey (USGS) began continuous monitoring of suspended sediment concentration in 1991. Continuous suspended sediment concentration monitoring stations were established in each major region of San Francisco Bay (Figure 1), establishing a continuous monitoring network. The sensors at each station measure the amount of material in the water every 15 minutes. Results are available on the internet at . In addition to the network, sensors have been deployed at as many as 14 additional sites in the Bay for periods of several months as part of focused studies of sediment transport in Bay locales of special interest.

California↗
USGS2002

Summary of suspended-sediment concentration data, San Francisco Bay, California, water year 2000

Suspended-sediment concentration data were collected in San Francisco Bay during water year 2000 (October 1, 1999?September 30, 2000). Optical backscatterance sensors and water samples were used to monitor suspended sediment at one site in Suisun Bay, three sites in San Pablo Bay, two sites in Central San Francisco Bay, and three sites in South San Francisco Bay. Sensors were positioned at two depths at most sites. Water samples were collected periodically and were analyzed for concentrations of suspended sediment. The results of the analyses were used to calibrate the electrical output of the optical backscatterance sensors. This report presents the data-collection methods and summarizes the suspended-sediment concentration data collected from October 1999 through September 2000. Calibration plots and plots of edited data for each sensor also are presented.

Open-File Report↗