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Watershed Characteristics Rating for North Carolina

Open File Report 01-490
By Silvia Terziotti, J.L. Eimers, and J.C. Weaver


Project Description

Metadata · Metadata as Plain Text file

Inherent vulnerability categories for rating watershed characteristics

Project Description for Map Data Produced as Part of the North Carolina Source Water Assessment Program


Abstract

This web site contains the Federal Geographic Data Committee-compliant metadata (documentation) for digital data produced for the North Carolina, Department of Environment and Natural Resources, Public Water Supply Section, Source Water Assessment Program. The metadata are for 11 individual Geographic Information System data sets. An overlay and indexing method was used with the data to derive a rating for unsaturated zone and watershed characteristics for use by the State of North Carolina in assessing more than 11,000 public water-supply wells and approximately 245 public surface-water intakes for susceptibility to contamination. For ground-water supplies, the digital data sets used in the assessment included unsaturated zone rating, vertical series hydraulic conductance, land-surface slope, and land cover. For assessment of public surface-water intakes, the data sets included watershed characteristics rating, average annual precipitation, land-surface slope, land cover, and ground-water contribution. Documentation for the land-use data set applies to both the unsaturated zone and watershed characteristics ratings. Documentation for the estimated depth-to-water map used in the calculation of the vertical series hydraulic conductance also is included.


Abstract || Introduction || Purpose || Contents || Links to Metadata || References

Introduction

Overlay and index methods for rating the unsaturated zone and watershed characteristics were derived for use by the State of North Carolina in assessing more than 11,000 public water-supply wells and approximately 245 public surface-water intakes for susceptibility to contamination. Factors that influence the vulnerability of public ground water and surface water supplies to contamination were selected and assigned ratings on a scale of 1 to 10, covering the range of values in North Carolina. These factors then were assigned weight to reflect their relative influence on the perceived inherent vulnerability and reliability of the data (Eimers and others, 2000).

Factors selected for rating the vulnerability to contamination of the unsaturated zone are vertical series hydraulic conductance, land-surface slope, land cover, and land use. Vertical series hydraulic conductance measures the capacity of unsaturated material to transmit water. Land-surface slope influences whether precipitation runs off land surfaces or infiltrates into the subsurface. Land cover describes the physical overlay of the land surface, which influences the amount of precipitation that runs off or infiltrates into the subsurface. Land use describes activities occurring on the land surface that influence the potential generation of nonpoint-source contamination.

In order to develop the unsaturated zone vulnerability rating, an estimated depth-to-water map was created. The estimated depth-to-water map was necessary for the calculation of the vertical series hydraulic conductance values. A documentation file was created describing methods and formulas that were applied to generate this data set.

Factors selected for rating the watershed characteristics upstream from surface-water intakes are average annual precipitation, land-surface slope, land cover, land use, and ground-water contribution. The average annual precipitation represents the amount of water available for transport in a watershed. Land-surface slope, land cover, and land use have similar influences on watershed characteristics as those identified for the unsaturated zone. Ground-water contribution represents the part of streamflow that is derived from ground water.

The values for each factor were obtained from Geographic Information System (GIS) data layers stored as raster data sets. These raster data sets have 30-meter by 30-meter cells, and each cell is assigned a value based on the characteristics of the factor within that cell. Only one data set was created for the land-use factor because identical ratings were applied for the unsaturated zone rating and watershed characteristics rating. The values for each factor were assigned a weight, then the weighted values were combined to create the final vulnerability values for the unsaturated zone and watershed characteristics ratings.

A structured documentation file (known as "metadata") for each data set has been created. The documentation files comply with the Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (Federal Geographic Data Committee, 1994). The FGDC-compliant metadata files contain descriptions of the data sets and include narrative sections describing the procedures used to produce the data sets in digital form. The metadata also include references of the sources used to create the data set.


Abstract || Introduction || Purpose || Contents || Links to Metadata || References

Purpose

This page provides background context for the 11 digital data sets created for the North Carolina Source Water Assessment Program (SWAP), and is the access point for all associated metadata files.


Abstract || Introduction || Purpose || Contents || Links to Metadata || References

Contents

The FGDC-compliant metadata for the 11 data sets are linked below. The digital data are not currently online because of space limitations. The digital data sets can be requested through the distribution contact identified in the metadata.


Abstract || Introduction || Purpose || Contents || Links to Metadata || References

Links to metadata

Links to jpeg images
of the data sets

Unsaturated Zone Characteristics Rating for North Carolina (OFR 01-489) Inherent vulnerability categories for rating the unsaturated zone
Percent-Slope Classes to Characterize the Unsaturated Zone in North Carolina (OFR 01-495) Percent slope categories for rating the unsaturated zone
Land-Cover Classes to Characterize the Unsaturated Zone in North Carolina (OFR 01-491) Landcover categories for rating the unsaturated zone
Vertical Series Hydraulic Conductance Classes to Characterize the Unsaturated Zone in North Carolina (OFR 01-486) Vertical hydraulic conductance categories for rating the unsaturated zone
Estimated Depth to Water, North Carolina (OFR 01-487) Depth to water
Land-Use Classes to Characterize Watersheds and the Unsaturated Zone in North Carolina (OFR 01-493) Landuse categories for rating the unsaturated zone and watershed characteristics
Watershed Characteristics Rating for North Carolina (OFR 01-490) Inherent vulnerability categories for rating watershed characteristics
Land-Cover Classes to Characterize Watersheds in North Carolina (OFR 01-492) Landcover categories for rating watershed characteristics
Average Annual Precipitation Classes to Characterize Watersheds in North Carolina (OFR 01-494) Average annual precipitation categories
Percent-Slope Classes to Characterize Watersheds in North Carolina (OFR 01-496) Percent slope categories for rating watershed characteristics
Ground-Water Contribution Classes to Characterize Watersheds in North Carolina (OFR 01-488) Ground-water contribution categories

Abstract || Introduction || Purpose || Contents || Links to Metadata || References

References

Eimers, J.L., Weaver, J.C., Terziotti, Silvia, and Midgette, R.W., 2000, Methods of rating unsaturated zone and watershed characteristics of public water supplies in North Carolina: U.S. Geological Survey Water-Resources Investigations Report 99-4283, 31 p.

Federal Geographic Data Committee, 1994, Content standards for digital geospatial metadata (June 8): Washington, D.C., Federal Geographic Data Committee, 78 p.



USGS home page

Watershed Characteristics Rating for North Carolina

Open File Report 01-490
By Silvia Terziotti, J.L. Eimers, and J.C. Weaver

Metadata

Metadata is also available as a Plain Text file.


Identification_Information:

Citation:
Citation_Information:
Originator: Silvia Terziotti, Jo Leslie Eimers and J. Curtis Weaver, USGS
Title: Watershed Characteristics Rating for North Carolina
Publication_Date: 2001
Edition: Version 1.0, February 9, 2001
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-490
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: U.S. Geological Survey
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01490/index.html

Description:
Abstract:

This data set represents the ratings applied to the watershed characteristics of surface water supplies for inherent vulnerability. It is one of 11 data sets developed for the North Carolina Source Water Assessment Program. The data sets are used to rate the susceptibility of public water supplies in North Carolina to contamination.

The selected factors contributing to watershed characteristics ratings are average annual precipitation, land-surface slope, land cover, land use, and ground-water contribution. For surface-water systems, the higher the inherent vulnerability of a watershed, the higher the rating applied on a scale of 10 to 100.

Purpose:

The purpose of this data set is to rate susceptibility to contamination for watershed characteristics of surface-water supplies.

Supplemental_Information:

The Federal Safe Drinking Water Act (SDWA) Amendments of 1996 emphasize pollution prevention as an important strategy for the protection of ground-water and surface-water resources. This new focus in the SDWA promotes the prevention of drinking water contamination as a cost-effective means of ensuring reliable, long-term, and safe drinking water sources for public water-supply systems (North Carolina Department of Environment and Natural Resources, 1999a). Specifically, Section 1453 of the SDWA Amendments requires that States develop and implement a Source Water Assessment Program (SWAP) to delineate source water areas, inventory potential contaminants in these areas, and determine the susceptibility of each public water supply to contamination. The agency charged with the task of susceptibility assessment in North Carolina is the Public Water Supply Section (PWSS) of the Department of Environment and Natural Resources. The U.S. Geological Survey (USGS) is directed under the Clean Water Action Plan, funded by Congress in 1999, to assist States with water-quality monitoring and susceptibility determinations.

The inherent vulnerability rating is a measure of the potential for contaminants within a delineated source area to reach the ground-water or surface-water supply. The inherent vulnerability of a ground-water source of public water supply is determined by combining an aquifer rating and an unsaturated zone rating (North Carolina Department of Environment and Natural Resources, 1999a). The inherent vulnerability of a surface-water source of public water supply is determined by combining a watershed classification, intake location, raw water quality (water plant data), North Carolina Division of Water Quality Use Support rating, and watershed characteristics rating (North Carolina Department of Environment and Natural Resources, 1999a). In cooperation with the PWSS, the USGS developed methods to rate unsaturated zones for public ground-water systems and watershed characteristics for public surface-water intakes. All other components of inherent vulnerability were compiled by the PWSS.

Overlay and index methods for rating susceptibility to contamination of the unsaturated zone for ground-water suppplies, and watershed characteristics for surface-water supplies were derived for use by the State of North Carolina in assessing more than 11,000 public water-supply wells and approximately 245 public surface-water intakes. Factors that influence the inherent vulnerability of ground water and surface water were selected and assigned ratings on a scale of 1 to 10. These factors were then assigned weight to reflect their relative influence on inherent vulnerability and the reliability of the data. The values for each factor were obtained from geographic information system (GIS) data layers that were transformed into Arc/Info raster data sets known as grids. These raster data sets have 30-meter by 30-meter cells, and each cell is assigned a weighted-factor value.

The identification of factors, development of ratings for each, and subsequent assignment of weights were based on (1) a literature search, which included examination of potential factors and their effects on the drinking-water quality; and (2) consultation with experts in the fields of hydrology, geology, forestry, agriculture, and water management. The relative rating of the unsaturated zone and watershed characteristics combines hydrologic data with expert knowledge to assess the vulnerability of water supplies to contamination.

Factors selected for rating the inherent vulnerability of the unsaturated zone to contamination are vertical series hydraulic conductance, land-surface slope, land cover, and land use. Vertical series hydraulic conductance measures the capacity of the unsaturated material to transmit water. Land-surface slope influences whether precipitation runs off land surfaces or infiltrates into the subsurface. Land cover describes the physical overlay of the land surface, which influences the amount of precipitation that runs off or infiltrates into the subsurface. Land use describes activities occurring on the land surface that influence the potential generation of nonpoint-source contamination.

Factors selected for rating vulnerability to contamination of the watershed upstream from surface-water intakes are average annual precipitation, land-surface slope, land cover, land use, and ground-water contribution. The average annual precipitation represents the mass of water that becomes available for transport in a watershed. Land-surface slope, land cover, and land use have similar influences on watershed characteristics as those identified for the unsaturated zone. In the cases of land-surface slope and land cover, the ratings for watershed characteristic vulnerability are the opposite of unsaturated zone vulnerability to contamination (i.e. more infiltration or ponding produces a higher vulnerability to ground-water, but less to surface-water sources.) Ground-water contribution represents the part of streamflow that is derived from ground-water discharge.

Limitations --

The overlay and index methods of unsaturated zone and watershed characteristics ratings are broad-stroke methods that assess vulnerability on the basis of expert opinion. The methods aslo have limitations in the age and scale of the hydrologic and geographic data. But the most significant limitation of the methods used is that no statistical confirmation of the results have been performed.

WATERSHED CHARACTERISTICS RATING--

The relative watershed characteristics rating is based on a combination of factors that contribute to the likelihood that contaminants from surface and shallow sources will reach a public surface-water supply intake by following the path of overland flow or shallow subsurface flow. The selected factors, which can be represented in the form of GIS spatial data layers, include average annual precipitation, land-surface slope, land cover, land use, and ground-water contribution.

The values of each of these five factors are categorized, and the categories are assigned a rating on a scale of 1 to 10. A rating of 1 reflects a low contribution to inherent vulnerability and 10 reflects a high contribution. For example, the rating for land-surface slope is low (1) in areas of low slope (greater than 50 percent) and high (10) in areas of high slope (less than 2 percent) because increased runoff potential in steeper terrain leads to an increased likelihood of surface-water contamination.

With the exception of land use, these factors describe influences on the physical transport of water, with or without contaminants. The land-use factor is included as a measure of the potential for generating nonpoint-source contamination at land surface.

To determine the watershed characteristics rating, the five factors are weighted on the basis of weighted on the basis of importance of the factor in determining vulnerability.

For each cell, the product of the factor weights and ratings are summed to determine the total rating for the cell, resulting in a relative numerical watershed characteristics rating that ranges from 10 to 100 for each cell.

Factors contributing to the watershed characteristics rating.

Factor contributing to the watershed characteristics      Weight
rating -- Description

Average annual precipitation                                 3
The average annual precipitation is a measure of the
amount of water (with or without contaminants) that
travels overland or through the shallow subsurface to
streams or lakes.

Land-surface slope                                           2
The inclination or slope of the land surface influences
the likelihood that precipitation will run off or
infiltrate into the ground.

Land cover                                                   1
The type of material covering the land surface
influences the likelihood that precipitation will
run off or infiltrate into the ground.

Land use                                                     3
The type of land use influences the likelihood
that potential non-point source contaminants will
be generated.

Ground-water contribution                                    1
The portion of surface water derived from ground
water influences surface-water quantity and quality.

SELECTED REFERENCE:

Eimers, J. L., Weaver, J. C., Terziotti, S., and Midgette, R. W., 2000, Methods of rating unsaturated zone and watershed characteristics of public water supplies in North Carolina: U. S. Geological Survey Water-Resources Investigations Report 99-4283, 31 p.

North Carolina Department of Environment and Natural Resources, 1999, North Carolina source water assessment program plan: Raleigh, North Carolina Department of Environment and Natural Resources, Division of Environmental Health, Public Water Supply Section, [variously paged].

DISCLAIMER:

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in ARC/INFO format, this metadata file may include some ARC/INFO-specific terminology.

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2001
Currentness_Reference: Ground Condition

Status:
Progress: In work
Maintenance_and_Update_Frequency: As Needed

Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -84.90706954
East_Bounding_Coordinate: -75.16688733
North_Bounding_Coordinate: 37.49637014
South_Bounding_Coordinate: 33.05247366

Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: Inherenent Vulnerability
Theme_Keyword: precipitation
Theme_Keyword: land use
Theme_Keyword: land cover
Theme_Keyword: ground water contribution
Theme_Keyword: slope
Theme_Keyword: elevation
Theme_Keyword: surface water
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: North Carolina

Access_Constraints:
none

Use_Constraints:
Not to be used for site specific analysis

Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Silvia Terziotti
Contact_Organization: U.S. Geological Survey
Contact_Position: Computer Specialist
Contact_Address:
Address_Type: mailing address
Address: 3916 Sunset Ridge Road
City: Raleigh
State_or_Province: NC
Postal_Code: 27607
Country: USA
Contact_Voice_Telephone: (919) 571-4000
Contact_Facsimile_Telephone: (919) 571-4041
Contact_Electronic_Mail_Address: (seterzio@usgs.gov)

Data_Set_Credit:
The authors are grateful to colleagues in the Public Water Supply Section of the North Carolina Division of Environmental Health, Department of Environment and Natural Resources for their assistance in this collaborative project-- thanks to Elizabeth Morey, Hydrogeologist; Gale Johnson, Hydrogeologist; and Rajpreet Butalia, Geographic Information Systems Coordinator.

The authors also thank the following scientists and engineers who provided additional technical review of this work:

* Richard Burns, Watershed and Forest Hydrologist, U.S. Forest Service,
  [U.S. Department of Agriculture]
* Ron Coble, Professional Geologist (Retired USGS)
* Ed Holland, Orange County Water and Sewer Authority
* Beth McGee, Clean Water Management Trust Fund
* Ted Mew, Groundwater Section, Division of Water Quality, North
  Carolina DENR
* Joe Rudek, Environmental Defense Fund
* Henry Wade, Pesticides Section, North Carolina Department of
  Agriculture
* Steve Zoufaly, Division of Water Quality, North Carolina DENR

The authors also thank the USGS report review team for their review of the metadata products: Stephen J. Char, Jason M. Fine, Michael L. Strobel, Douglas A. Harned and Rebecca J. Deckard.

Native_Data_Set_Environment:
Windows_NT, 5.0, Intel
ARC/INFO version 8.0.2

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Watershed Characteristics Rating for North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-490
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01490/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Unsaturated Zone Characteristics Rating for North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-489
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01489/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Land-Use Classes to Characterize Watersheds and the Unsaturated Zone in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-493
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01493/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Land-Cover Classes to Characterize the Unsaturated Zone in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-491
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01491/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Percent-Slope Classes to Characterize the Unsaturated Zone in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-495
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01495/index.html

Cross_Reference:
Citation_Information:
Originator: Jo Leslie Eimers, Silvia Terziotti and Gloria Ferrell
Publication_Date: 2001
Title: Vertical Series Hydraulic Conductance Classes to Characterize the Unsaturated Zone in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-486
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01486/index.html

Cross_Reference:
Citation_Information:
Originator: Jo Leslie Eimers, Silvia Terziotti and Mary Giorgino
Publication_Date: 2001
Title: Estimated Depth to Water, North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-487
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01487/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Land-Cover Classes to Characterize Watersheds in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-492
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01492/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Average Annual Precipitation Classes to Characterize Watersheds in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-494
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01494/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Percent-Slope Classes to Characterize Watersheds in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-496
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01496/index.html

Cross_Reference:
Citation_Information:
Originator: Silvia Terziotti and Jo Leslie Eimers
Publication_Date: 2001
Title: Ground-Water Contribution Classes to Characterize Watersheds in North Carolina
Geospatial_Data_Presentation_Form: map
Series_Information:
Series_Name: USGS Open-File Report
Issue_Identification: USGS OFR 01-488
Publication_Information:
Publication_Place: Raleigh, NC
Publisher: USGS
Online_Linkage: http://nc.water.usgs.gov/reports/ofr01488/index.html


Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
visually verified against original source

Logical_Consistency_Report:
Not applicable for raster data.

Completeness_Report:
Completed for the State of North Carolina.

Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
visually verified

Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: Eimers, J. L.
Originator: Weaver, J. C.
Originator: Terziotti, S.
Originator: Midgette, R. W.
Title: Methods of rating unsaturated zone and watershed characteristics of public water supplies in North Carolina
Publication_Date: 2000
Series_Information:
Series_Name: U. S. Geological Survey Water-Resources Investigations
Issue_Identification: WRIR 99-4283
Type_of_Source_Media: paper
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2000
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Eimers and others (2000)
Source_Contribution: methods for applying ratings

Process_Step:
Process_Description:
Create a floating point grid based on the weighted values of the contributing factors.
INHER_SW = ( landcoversw * 2 ) + ( landusesw * 3 ) +
( precipsw * 3 ) + ( slopesw * 1 ) + ( ( gwcontrib) div 10 * 1 )
Process_Date: 2001

Process_Step:
Process_Description:
First draft of metadata created by seterzio using FGDCMETA.AML ver. 1.33 07/15/99 on ARC/INFO data set x:\sw_layers\inher_sw
Process_Date: 20010209


Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Raster
Raster_Object_Information:
Raster_Object_Type: Grid Cell
Row_Count: 16163
Column_Count: 28734


Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: State Plane Coordinate System 1983
State_Plane_Coordinate_System:
SPCS_Zone_Identifier: 4901
Lambert_Conformal_Conic:
Standard_Parallel: 34.333
Standard_Parallel: 36.167
Longitude_of_Central_Meridian: 79.000
Latitude_of_Projection_Origin: 33.750
False_Easting: 2000000
False_Northing: 0.000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 30.0
Ordinate_Resolution: 30.0
Planar_Distance_Units: Meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: GRS1980
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.98


Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
Value attribute table, INHER_SW.VAT:

COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
    1  VALUE                  4    10     B      -
    5  COUNT                  4    10     B      -

Value is rating between 10 and 100.
Count is the number of 30 meter by 30 meter cells that have the
value in positive integers.
In the final data set, the values range from 13 to 95.

Summary statistics table, INHER_SW.STA:

COLUMN   ITEM NAME        WIDTH OUTPUT  TYPE N.DEC  ALTERNATE NAME
    1  MIN                    8    15     F      3
    9  MAX                    8    15     F      3
   17  MEAN                   8    15     F      3
   25  STDV                   8    15     F      3

   MIN             MAX            MEAN            STDV
13.000          95.000          31.478           9.987
Min is the minumum value.
Max is the maximum value.
Mean is the average value.
STDV is the standard deviation.
Entity_and_Attribute_Detail_Citation: none


Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Position: Water Webserver Team
Contact_Address:
Address_Type: mailing and physical address
Address: 12201 Sunrise Valley Drive, MS 440
City: Reston
State_or_Province: VA
Postal_Code: 20192
Country: USA
Contact_Voice_Telephone: (800) 426-9000
Contact_Instructions: Contact via email
Contact_Electronic_Mail_Address: h2oteam@usgs.gov

Distribution_Liability:

Although these data have been used by the U.S. Geological Survey, U.S. Department of the Interior, no warranty expressed or implied is made by the U.S. Geological Survey as to the accuracy of the data.

The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the U.S. Geological Survey in the use of this data, software, or related materials.


Metadata_Reference_Information:
Metadata_Date: 20010209
Metadata_Review_Date: 2001
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. Geological Survey
Contact_Person: North Carolina District Chief
Contact_Position: District Chief
Contact_Address:
Address_Type: mailing and physical address
Address: 3916 Sunset Ridge Road
City: Raleigh
State_or_Province: NC
Postal_Code: 27607
Country: USA
Contact_Voice_Telephone: (919) 571-4000
Contact_Facsimile_Telephone: (919) 571-4041
Contact_Electronic_Mail_Address: dc_nc@usgs.gov
Metadata_Standard_Name:
FGDC Content Standards for Digital Geospatial Metadata
("CSDGM version 2")
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Access_Constraints: none
Metadata_Use_Constraints: none


Generated by mp version 2.4.33 on Tue Jan 22 10:16:03 2002
USGS GIS Data for Water Resources || North Carolina District
Last update: Wednesday, December 19 2012, 02:07:44 PM
URL: http://nc.water.usgs.gov/reports/ofr01490/index.html
Privacy Statement || Disclaimer || Accessibility
Maintainer: North Carolina Web Development Team