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National Water-Quality Assessment (NAWQA) Study-Unit Investigations in the conterminous United States : Surface Water Nutrient Sampling Sites

Federal Geographic Data Committee (FGDC) Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Hitt, K.J. and Nakegaki, N.
Publication_Date: 19990701
Title: National Water-Quality Assessment (NAWQA) Study-Unit Investigations in the conterminous United States : Surface Water Nutrient Sampling Sites
Edition:
Geospatial_Data_Presentation_Form: Map
Series_Information:
Series_Name:
Issue_Identification:
Publication_Information:
Publication_Place: Reston, VA
Publisher: USGS
Other_Citation_Details:
Online_Linkage: http://www.epa.gov/airmarkets/
Description:
Abstract:
This is a point coverage of the sampling sites for the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program Study-Unit investigations of Surface Water Nutrients for the conterminous United States, excluding the High Plains Regional Ground-Water Study. It is intended for use with NAWQA_NU.DBF and as an overlay with NAWQA, the NAWQA study units boundary coverage. The National Water-Quality Assessment Program is designed to describe the status and trends in the quality of the Nation's ground- and surface-water resources and to provide a sound understanding of the natural and human factors that affect the quality of these resources (Leahy and others, 1990). A "Study Unit" is a major hydrologic system in which NAWQA studies are focused. Study Units are geographically defined by a combination of ground- and surface-water features (Gilliom and others, 1995). As part of the NAWQA program, Study-Unit investigations were planned for 60 areas throughout the Nation to provide a framework for national and regional water-quality assessments (Leahy and others, 1990). The 60 planned Study-Units were divided into three groups of 20. Each group would be intensively studied on a rotational basis with 20 studies beginning in fiscal year 1991 (FY 1991 runs from October 1990-September 1991), 20 more studies beginning in fiscal year 1994 (October 1993-September 1994), and the final 20 studies beginning in fiscal year 1997 (October 1996-September 1997). Each study cycle would span 10 years. In 1996, the number of Study-Units was scaled back to 59 when two of the original 60 Study Units combined. Also, because of budgetary restraints, some of the original planned Study Units have been scheduled to start later than originally planned and others have not even been scheduled to start yet. This coverage contains basic geographic information about the 213 surface water sites that were sampled for nutrients as part of NAWQA within the conterminous United States, excluding the High Plains Regional Ground Water-Study, which was conceived in late 1997. The coverage also includes the NAWQA standard abbreviation of each Study Unit, the station identification code, sampling type, land-use type, percentages of specific land use types, and latitude and longitude coordinates. The stream data are the results from 8459 water samples collected at 213 surface water sites across the conterminous United States. All of the sampling sites are located in the 20 major watersheds that comprise the first group of NAWQA study units. Samples were collected from October 1991 through December 1996. About 90 percent of the samples were collected during 1993, 1994, and 1995. All samples were flow-weighted and cross-sectionally integrated by standard USGS methods (Ward and Harr, 1990). Sampling at many sites was not spaced evenly throughout the year. Sampling at the intensive fixed sites was more frequent during periods when pesticide levels were expected to be elevated. At the basic fixed sites, extra samples were collected during extreme flow conditions. Thus, care must be used in the interpretation of these data. For example, summary statistics such as the mean or median concentration for a specific compound may be biased unless procedures are used to account for the uneven sampling frequency. In addition, the number of samples collected varied considerably among the sites. Thus, the results shown in the surface water data file are influenced more by conditions at some sites than others. Data analysis procedures that account for this unequal distribution of samples among the sites must be used to avoid biased interpretations. This data set is used primarily to display the location of NAWQA Surface Water Nutrient Study Sites and for use with the NAWQA Study Unit boundaries coverage (NAWQA) for analysis of data at the national scale. It is not recommended for either local or regional analysis due to the small scale of most of the features. Results from the first cycle of National Water-Quality Assessment Program (NAWQA) water-quality data collection during 1992-1996 include analyses of 8 nutrient species and 11 other inorganic constituents from about 2,200 samples of ground water and from about 8,500 samples of streams and rivers in 20 of the nation's major watersheds (NAWQA study units). The characteristics of the NAWQA nutrients data are described below, followed by viewable samples of the data and downloadable data files. The data set used for national synthesis is from the February 1998 compilation. Overview of Sampling Design and Considerations for Data Interperation: NAWQA studies are based on a complex sampling design that targets specific land use and hydrologic conditions in addition to assessing the most important aquifers and large streams and rivers in each area studied. For streams, rivers, and ground water, a major component of the sampling design is to target specific watersheds and shallow ground water areas that are influenced primarily by a single dominant land use (agricultural or urban) that is important in a particular area of the United States. This aspect of the sampling design facilitates summarizing results by agricultural and urban land use settings for both streams and ground water. However, the results from this design require careful interpretation, because this design results in a biased representation of all streams or shallow ground water in agricultural settings. For agricultural land use, the focus was limited to the most important agricultural settings within the first 20 study units. Thus, some agricultural activities that may be important in other parts of the nation may not be included. The user is encouraged to consider the detailed descriptions of the nature and limitations of the stream and ground water data that are provided. [Summary provided by the EPA.]
Purpose:
Not Available
Supplemental_Information:
Not Available
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Description_of_Geographic_Extent:
Bounding_Coordinates:
West_Bounding_Coordinate: -127.88
East_Bounding_Coordinate: -65.35
North_Bounding_Coordinate: 48.25
South_Bounding_Coordinate: 22.87
Keywords:
Theme:
Theme_Keyword_Thesaurus: GCMD SCIENCE PARAMETERS
Theme_Keyword_Thesaurus: PROJECT
Theme_Keyword_Thesaurus: ANCILLARY KEYWORDS
Theme_Keyword_Thesaurus: ISO TOPIC CATEGORY
Theme_Keyword_Thesaurus: DATA SET LANGUAGE
Theme_Keyword: EARTH SCIENCE > HUMAN DIMENSIONS > ENVIRONMENTAL GOVERNANCE/MANAGEMENT > WATER MANAGEMENT
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > GROUND WATER > GROUND WATER FEATURES > AQUIFERS
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > GROUND WATER > GROUND WATER FEATURES > FRESHWATER SPRINGS
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > SURFACE WATER
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > DISSOLVED GASES
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > ORGANIC MATTER
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > OXYGEN
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > PHOSPHOROUS COMPOUNDS
Theme_Keyword: EARTH SCIENCE > TERRESTRIAL HYDROSPHERE > WATER QUALITY/WATER CHEMISTRY > WATER TEMPERATURE
Theme_Keyword: EARTH SCIENCE > HUMAN DIMENSIONS > ENVIRONMENTAL GOVERNANCE/MANAGEMENT > ENVIRONMENTAL ASSESSMENTS
Theme_Keyword: ESIP > EARTH SCIENCE INFORMATION PARTNERS PROGRAM
Theme_Keyword: C-MAP > CLEAN AIR MAPPING AND ANALYSIS PROGRAM
Theme_Keyword: Gis
Theme_Keyword: Usgs
Theme_Keyword: National Water Quality Assessment Program
Theme_Keyword: Nawqa
Theme_Keyword: Surface Water
Theme_Keyword: Ground Water
Theme_Keyword: Drinking Water
Theme_Keyword: Fresh Water
Theme_Keyword: Human Health
Theme_Keyword: Environmental Health
Theme_Keyword: Water Quality
Theme_Keyword: Nutrients
Theme_Keyword: Sampling Sites
Theme_Keyword: Water Resources
Theme_Keyword: ENVIRONMENT
Theme_Keyword: GEOSCIENTIFIC INFORMATION
Theme_Keyword: HEALTH
Theme_Keyword: INLAND WATERS
Theme_Keyword: ENGLISH
Place:
Place_Keyword_Thesaurus: GCMD
Place_Keyword: CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Access_Constraints: None
Use_Constraints:
Not Available
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Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
This data set is used primarily to display the location of NAWQA Nutrient Study Sites and for use with the NAWQA Study Unit boundaries coverage (NAWQA) for analysis of data at the national scale. It is not recommended for either local or regional analysis due to the small scale of most of the features. The dataset was created from Latitude/Longitude coordinates using ArcView GIS. A shapefile was created from lat/long coordinates and was then converted into a coverage using ArcInfo. The coverage was re-projected into Albers for use with other CAMD GIS coverages.
Logical_Consistency_Report:
Not Available
Completeness_Report:
Not Available
Lineage:
Process_Step:
Process_Description:
Not Available
Process_Date: Unknown
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Spatial_Reference_Information:
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: EPA/CAMD > Clean Air Markets Division, U.S. Environmental Protection Agency
Contact_Person: EPA CLEAN AIR MARKETS DIVISION
Contact_Position: DATA CENTER CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: US EPA
Address: Clean Air Markets Division
Address: 1200 Pennsylvania Avenue, NW
Address: Mail Code 6204J
City: Washington
State_or_Province: DC
Postal_Code: 20460
Country: USA
Contact_Voice_Telephone: 202-564-9180
Contact_Electronic_Mail_Address: camdgis@epa.gov
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: DOI/USGS/WRD/GIS > Water Resources Maps and GIS Information, Water Resources Division, U.S. Geological Survey, U.S. Department of the Interior
Contact_Person: KERRIE J. HITT
Contact_Position: DATA CENTER CONTACT
Contact_Address:
Address_Type: Mailing and Physical Address
Address: U.S. Geological Survey
Address: 12201 Sunrise Valley Drive
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: 703-648-6854
Contact_Electronic_Mail_Address: kjhitt@usgs.gov
Resource_Description: NAWQA_NU
Distribution_Liability:
Not Available
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ArcView shapefile
Transfer_Size: 20 KB
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://www.epa.gov/airmarkets/
Access_Instructions:
DATA CENTER URL
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://water.usgs.gov/lookup/getgislist
Access_Instructions:
DATA CENTER URL
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://gcmd.nasa.gov/getdif.htm?EPA0175
Access_Instructions:
GCMD metadata on the National Water Quality Assessment Program (NAWQA). This record provides metadata on the original tabular nonspatial data.
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://www.epa.gov/airmarkets/
Access_Instructions:
FGDC metadata on &National Water-Quality Assessment Program: Surface Water Nutrient Sampling Sites&.
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name:
http://water.usgs.gov/nawqa/
Access_Instructions:
Homepage of the USGS National Water Quality Assessment Program (NAWQA).
Fees: No Fees
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Metadata_Reference_Information:
Metadata_Date: 20021115
Metadata_Review_Date: 20160127
Metadata_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: TYLER B. STEVENS
Contact_Position: DIF AUTHOR
Contact_Address:
Address_Type: Mailing and Physical Address
Address: NASA Goddard Space Flight Center
Address: Global Change Master Directory
City: Greenbelt
State_or_Province: MD
Postal_Code: 20771
Country: USA
Contact_Voice_Telephone: (301) 614-6898
Contact_Facsimile_Telephone: 301-614-5268
Contact_Electronic_Mail_Address: Tyler.B.Stevens@nasa.gov
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
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