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J. R. Gray

Publications and source records attributed to J. R. Gray.

25 records · Page 2Linked to original sources
USGS1997

Overview of USGS sediment research and monitoring capabilities

For more than a century the USGS, as its name implies, has been the leading federal earth science research organization for the Nation. With the recent addition to the USGS of the National Biological Service in October 1996, as the Biological Resources Division, the mission of the USGS has broadened and the Survey's research capabilities are strengthened considerably. The USGS is now in a position to provide objective and credible scientific information across the fields of geology, geophysics, hydrology, geography, and biology and to provide the science information in an integrated and truly multidisciplinary manner. The subject of sediment is one that is critical to nearly every activity in the USGS and is becoming increasingly important to society and protecting, sustaining, and restoring the Nation's natural resources. The purpose of this workshop is to focus on this common denominator, sedimentary research, and bring together investigators to examine areas of expertise and collaboration on existing studies and to explore potential for future scientific interaction across all four of the divisions. A brief summary of sediment research capability for each division follows.

Conference Paper↗
USGS1996

Streamflow transport of radio-nuclides and other chemical constituents in the Puerco and the Little Colorado River Basins, Arizona and New Mexico

Samples collected at streamflow-gaging stations in the Puerco and Little Colorado rivers show that radioactivity of suspended sediment at gaging stations downstream from inactive uranium mines was not significantly higher than at gaging stations where no mining has occurred upstream. Drinking-water standards for many constituents, however, commonly are exceeded during runoff because concentration of these constituents on sediment from natural processes is high and suspended-sediment loads are high during runoff.

Arizona, New Mexico↗
USGS1984

Runoff, sediment transport, and water quality in a northern Illinois agricultural watershed before urban development, 1979-81

A study designed to quantify and evaluate changes in runoff and sediment transport attributable to construction activities during urban development of a watershed required identification of pre-construction hydrologic conditions. Data collected before construction on a 2.81 sq m (7.28 sq km) agricultural watershed (upper Spring Creek) near Rockford, IL, show that during a 2-year period ending June 30, 1981, 2,890 tons (2,620 Mg) of suspended sediment were transported from the watershed. Of the 2 ,890 tons (2,620 Mg), 2,690 tons (2,440 Mg) or 93.1 % were transported during a storm in a 46.6-hour period of June 13-14, 1981. Runoff from a 0.031 sq m (0.080 sq km) subbasin (Spring Creek tributary) transported 33.9 tons (30.9 Mg) of suspended sediment during a 3.2-hour storm period on June 13, 1981. Regression models relating storm suspended-sediment yields and peak-water discharge per square mile for upper Spring Creek and Spring Creek tributary have average standard errors of 57 and 24 %, respectively. Trace amounts of currently banned pesticides, including Aldrin and DDT, were detected in streambed material samples. Documented sediment yields, chemical quality, and relations between runoff and sediment discharge provide baseline information for future evaluation of hydrologic conditions in the watershed. (USGS)

Water-Resources Investigations Report↗