Michael F. Barad, University of California, Davis
S. Geoffrey Schladow, University of California, Davis
John C. Warner, United States Geological Survey, WRD, Sacramento, California
David H. Schoellhamer, United States Geological Survey, WRD, Sacramento,
California
Several major environmental stressors influence the San Francisco Estuary. These include altered flow regimes; altered sediment regimes; heavy metal and pesticide residues from California's Central Valley, the Sierra Nevada, and the coastal range; industrial waste from the San Francisco Bay area (including several oil refineries); chemical waste from the now-closed Mare Island Naval Shipyard; and many other point and nonpoint sources. A long-term monitoring network is necessary for measuring the effects of these stressors on the estuary and for detecting any links among them.
A Coastal Intensive Site Network (CISNet) of 12 monitoring stations in San Pablo Bay, within the San Francisco Estuary, was established to provide hydrodynamic and water- quality observations during the period from January 1999 to March 2001. The monitoring stations were located in the major rivers feeding into the bay and in two marshes along the bay. Continuous measurements of velocity, depth, conductivity, temperature, and optical backscatterance (OBS) samples were collected at a 15-minute frequency at 7 of the 12 monitoring stations. In addition to the continuous monitoring at point locations, profiles through the water column were sampled at some of the sites using an acoustic Doppler profiler (ADP) and a conductivity-temperature-depth (CTD) profiler. An excellent range of temporal and spatial high-frequency data were collected during two 30-hour periods on July 1999 and July 2001 in the Napa River, which feeds into San Pablo Bay. Boat-mounted ADP and CTD-OBS profilers and bottom-mounted ADPs and CTD-OBS instruments were used to characterize the hydrodynamics of the river.
A matrix of data-collection times and locations stored in an easy-to-access format that allows sorting and filtering has been developed. The database matrix allows easy lookup of data availability and cross-referencing with other datasets and needs. There is a wide spectrum of uses for this database. For example, a user can access measurements of salinity and temperature at a specific site within a selected depth range, for a subset in time; locate and then spatially plot measurements of suspended sediment and temperature near the surface for a given area defined by latitude and longitude; or extract data needed for the boundary forcing of a model or to validate a model of hydrodynamics and constituent transport in the area. Sample datasets will be presented in graphical format to illustrate these and other potential uses. The CISNet database provides a useful and revealing view of many of the physical processes occurring in San Pablo Bay.