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George Porterfield

Publications and source records attributed to George Porterfield.

8 recordsLinked to original sources
USGS1980

Sediment transport of streams tributary to San Francisco, San Pablo, and Suisun Bays, California, 1909-66

A review of historical sedimentation data is presented, results of sediment-data collection for water years 1957-59 are summarized, and long-term sediment-discharge estimates from a preliminary report are updated. Comparison of results based on 3 years of data to those for the 10 water years, 1957-66, provides an indication of the adequacy of the data obtained during the short period to define the long-term relation between sediment transport and streamflow. During 1909-66, sediment was transported to the entire San Francisco Bay system at an average rate of 8.6 million cubic yards per year. The Sacramento and San Joaquin River basins provided about 83% of the sediment inflow to the system annually during 1957-66 and 86% during 1909-66. About 98% of this inflow was measured or estimated at sediment measuring sites. Measured sediment inflow directly to the bays comprised only about 40% of the total discharged by basins directly tributary to the bays. About 90% of the total sediment discharge to the delta and the bays in the San Francisco Bay system thus was determined on the basis of systematic measurements. (USGS)

California↗
USGS1978

Sediment transport in the Feather River, Lake Oroville to Yuba City, California

Regulation of the Feather River by Oroville Dam and reservoir in northeast California (beginning in 1967) changed the streamflow and sediment discharge downstream from the dam. Changes in channel geometry to adjust to the new regimen were still in process in 1975. Streamflow and sediment concentration and discharge had decreased. Median streamflow at Feather River near Gridley and Feather River at Yuba City, 27 miles and 49 miles downstream from the dam, had not changed, although the frequency of flow rates less than median increased and the frequency of flow rates greater than median, and which transport most sediment, decreased. Sediment-transport data indicate an increase in sediment yield from the 1965-67 period to the 1968-75 period in the basin downstream from Gridley to Yuba City , although the quantity of sediment transported was reduced owing to removal of sediment by Oroville Dam and to reduced streamflow. The increase in yield, assuming no change in tributary inflow, may be attributed partly to channel erosion accelerated by the clear-water releases and to the change in frequency and magnitude of flow rates.

California↗
USGS1972

An inventory of published and unpublished fluvial-sediment data for California, 1956-70

This inventory was prepared to provide a convenient reference to published and unpublished fluvial-sediment data for water years 1956-70, and updates substantially previous inventories. Sediment stations are listed in downstream order, and an alphabetical list of stations is also included. Figure 1 shows the approximate location of sediment stations in California. Most of the fluvial-sediment data in California were collected by the U.S. Geological Survey, under cooperative agreements with the following Federal, State, and local agencies: California Department of Water Resources, California Department of Navigation and Ocean Development, California Department of Fish and Game, Bolinas Harbor District, Monterey County Flood Control and Water Conservation District, Orange County Flood Control District, Riverside County Flood Control and Water Conservation District, San Diego County Department of Sanitation and Flood Control, San Luis Obispo County, San Mateo County, Santa Clara County Flood Control and Water District, Santa Cruz County Flood Control and Water Conservation District, Santa Cruz, city of, University of California, Ventura County Flood Control District, Forest Service, U.S. Department of Agriculture, Soil Conservation Service, U.S. Department of Agriculture, Corps of Engineers, U.S. Army, Bureau of Reclamation, U.S. Department of the Interior, National Park Service, U.S. Department of the Interior. This report was prepared by the Geological Survey under the general supervision of R. Stanley Lord, district chief in charge of water-resources investigations in California.

California↗
USGS1972

Sediment transport and deposition, Walnut and Pacheco Creeks, Contra Costa County, California, August 1965-April 1970

Average annual sediment discharge in Pacheco Creek basin, Contra Costa County, Calif., was larger during August 1965-April 1970 than the historical annual sediment discharge (1909-62) by a factor of about 1.3. This increas in sediment discharge is attributed primarily to an increased frequency of peak streamflows and to a larger average annual streamflow during the 1965-70 period.

California↗
USGS1972

Computation of fluvial-sediment discharge

This report is one of a series concerning the concepts, measurement, laboratory procedures, and computation of fluvial-sediment discharge. Material in this report includes procedures and forms used to compile and evaluate particle-size and concentration data, to compute fluvial-sediment discharge, and to prepare sediment records for publication.

Techniques of Water-Resources Investigations↗