.RU

Sources of Data for Nutrient Concentrations and Flow in Streams - This report has been reviewed for Director’s Approval...

Sources of Data for Nutrient Concentrations and Flow in Streams


Several sources of data, primarily in electronic form, were considered in this study. In addition to combining data from several sources, several similar water-quality parameters and sites were combined in this study to attempt to create the best long-term database for analysis of trends and loads. Data were retrieved for 1975–2004 for all sites. The influence of different sample collection and analytical methods on the long-term database was considered, as were issues relating to data frequency, detection limits, and reporting levels.

Data Sources


Although water-quality data were retrieved for many other parameters (field parameters, organic carbon, chlorophyll, and selected minerals), the parameters evaluated in this study were selected forms of nitrogen (nitrate, ammonia, and TN) and phosphorus (orthophosphate and TP). The data collection emphasized the dissolved forms of nitrate, ammonia, and orthophosphate. The final water-quality database used for this study included data from the following electronic sources: U.S. Environmental Protection Agency’s STOrage and RETrieval database (STORET), U.S. Geological Survey’s National Water Information System (NWIS) database, DWR, University of California at Davis (UCD), Sacramento River Watershed Program (SRWP), Sacramento Regional County Sanitation District (SRCSD), and the California Regional Water Quality Control Board, Central Valley Region (RWQCB(CVR)). All available data for sites of interest were included from the USGS, DWR, and UCD databases. Data from the other sources were used as needed to fill in gaps in time for sites of interest. The STORET database provided data for the 1975–1988 time period primarily, as after 1988 most of the agencies that were providing data to STORET stopped doing so. This included data provided by DWR, Bureau of Reclamation, and California State Water Resources Control Board (SWRCB) primarily. Data provided by these agencies in STORET are simply identified as STORET data and not by agency because in many cases more than one agency entered the same data. Thus, in removing these duplicates, it was difficult to identify the true collecting agency.

All USGS data used in this study came from the NWIS database. Data identified as DWR came from various sources. The 1988–1998 data primarily came from the individual districts of the DWR (Northern, Central, San Joaquin, and Southern Districts) as Microsoft® Excel spreadsheets, and since for the period after 1998, most of the DWR data were obtained from the Water Data Library, at URL: . Some DWR data also were obtained from a database maintained by the Interagency Ecological Program, available at URL: . The UCD data were obtained from Dr. Randy Dahlgren as an Microsoft® Excel spreadsheet. The UCD data were collected from several sites in the Sacramento and San Joaquin Basins for 1999–2004. The SRWP and the SRCSD data were obtained from Larry Walker and Associates. All or part of the SRWP data for eight sites were included in the database as were the SRCSD data for two sites in the Sacramento Basin (Sacramento River at Verona and American River at Nimbus Dam). The RWQCB(CVR) data for one site in the San Joaquin Basin (SJR at Fremont Ford) were obtained from their database at URL: .

Historical nitrate data were acquired for eight Sacramento Basin sites, four San Joaquin Basin sites, and three Santa Ana Basin sites. Data for 1905–07, 1908, and 1930–32 were obtained from three USGS studies (Van Winkle and Eaton, 1910; Stabler, 1911; California Department of Public Works, Division of Water Resources, 1931). Data for these sites between 1932 and 1975 were from either NWIS or STORET.
2010-07-19 18:44 Читать похожую статью
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • Контрольная работа
  • © Помощь студентам
    Образовательные документы для студентов.