Metadata: Identification_Information: Citation: Citation_Information: Originator: James Wichkam, US EPA Publication_Date: 1998 Title: ndvi_huc Edition: 1 Geospatial_Data_Presentation_Form: Map Publication_Information: Publication_Place: Norris TN Publisher: Tennessee Valley Authority Description: Abstract: NDVI (Normalized Difference Vegetation Index) is an index of the amount of biomass or green vegetation, and is measured as the ratio of infrared minus red over infrared plus red [(IR-red) / (IR + red) ] (Tucker 1979). Temporal change in NDVI was measured using Landsat MSS data from ca. 1970 and ca. 1990 that were acquired for the North American Landscape Characterization (NALC) program (USEPA 1993). The Landsat MSS bands used for NDVI were 4 (800-1100nm [IR]) and 3 (700-800 nm [red]). Purpose: These data were created as part of a regional assessment of landscape conditions in the mid-Atlantic region (SFR 3) (Jones et al., 1997). Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: Ending_Date: Currentness_Reference: Status: Progress: Complete Maintenance_and_Update_Frequency: None planned Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -84 degrees West East_Bounding_Coordinate: -74 degrees West North_Bounding_Coordinate: 43 degrees North Keywords: Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Vegetation Index Theme_Keyword: Satellite Imagery Theme_Keyword: Landcover Change Theme_Keyword: Theme_Keyword: Theme_Keyword: Place: Place_Keyword_Thesaurus: None Place_Keyword: United States Place_Keyword: Standard Federal Region III Access_Constraints: None Use_Constraints: None Point_of_Contact: Contact_Information: Contact_Person_Primary: Bruce Jones Contact_Person: Contact_Organization: EPA Landscape Ecology Division Contact_Address: Address_Type: mailing and physical address Address: U.S. Environmental Protection Agency, Box 93478 City: Las Vegas State_or_Province: Nevada Postal_Code: 89193-3478 Contact_Electronic_Mail_Address: jones.bruce@epamail.epa.gov Data_Set_Credit: Native_Data_Set_Environment: These data are presently stored in ARC/INFO format. Data_Quality_Information: Attribute_Accuracy: Attribute_Accuracy_Report: none Logical_Consistency_Report: none Completeness_Report: Positional_Accuracy: Horizontal_Positional_Accuracy: Horizontal_Positional_Accuracy_Report: The positional accuracy of the map is the same as the positional accuracy of the source map. Source_Information: Source_Citation: Citation_Information: Other_Citation_Details: Jones, K.B., Riitters, K.H., Wickham, J.D., Tankersley, R.D., O'Neill, R.V., Chaloud, D.J., Smith, E.R., and Neale, A.C. 1997. An Ecological Assessment of the United States Mid-Atlantic Region: A Landscape Atlas. EPA/600/R97/130, U.S. Environmental Protection Agency, Office of Research and Development, Washington, DC. Source_Information: Source_Citation: Citation_Information: Other_Citation_Details: Process_Step: Process_Description: NDVI (Normalized Difference Vegetation Index) is an index of the amount of biomass or green vegetation, and is measured as the ratio of infrared minus red over infrared plus red [(IR-red) / (IR + red) ] (Tucker 1979). Temporal change in NDVI was measured using Landsat MSS data from ca. 1970 and ca. 1990 that were acquired for the North American Landscape Characterization (NALC) program (USEPA 1993). The Landsat MSS bands used for NDVI were 4 (800-1100nm [IR]) and 3 (700-800 nm [red]). Two image processing steps were undertaken before comparing ca. 1970 and ca. 1990 NDVI measurements. First, the Landsat digital numbers for bands 3 and 4 were converted to effective or "at-satellite" reflectance following the procedures in Markham and Barker (1987). Second, the scene-to-scene normalization was performed using regression techniques. The data to drive the regressions were common bright (e.g., parking lots) and dark (deep, clear water bodies) targets (Schott et al. 1988). Temporal change in NDVI was then estimated as the difference between 1970 and 1990 measurements (i.e., 1970 - 1990). A positive value resulting from the differencing indicates that biomass has decrease over the time period. A negative value indicates and increase in biomass over time. Change in NDVI was estimated on a scene-by-scene basis. Scenes were merged on an as needed basis to derive estimates for USGS 8-digit watersheds. Estimates of change on a per watershed basis were used if there was 50 percent coverage for the watershed. Estimates of total change were based on a 1 standard deviation (std) threshold from a mean of zero (0) (Fung and LeDrew 1988). Differences less than 1 std were considered no change. References Fung, T. and LeDrew, E. 1988. The determination of optimal threshold levels for change detection using various accuracy indices. Photogrammetric Engineering and Remote Sensing, 54(10):1449-1454. Markham, B.L. and Barker, J.L. 1987. Radiometric properties of U.S. processed Landsat MSS data. Remote Sensing of Environment, 22:39-71. Schott, J.R., Salvaggio, C., and Volchok, W.J. 1988. Radiometric scene normalization using pseuodinvariant features. Remote Sensing of Environment, 26:1-16. Tucker, C.J. 1979. Red and photographic infrared linear combinations for monitoring vegetation. Remote Sensing of Environment, 8:127-150. USEPA 1993. North American Landscape Characterization Research Plan. USEPA/600/R-93/135, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA. Source_Used_Citation_Abbreviation: Source_Produced_Citation_Abbreviation: Process_Date: Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: vector Raster_Object_Information: Raster_Object_Type: Row_Count: Column_Count: Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Map_Projection: Map_Projection_Name: Lambert_Azimuthal Lambert_Azimuthal: Radius of Sphere of Reference: 6370997 Longitude_of_Central_Meridian: -100 0 0 Latitude_of_Projection_Origin: 45 0 0 False_Easting: 0.0 False_Northing: 0.0 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: Row and column Coordinate_Representation: Abscissa_Resolution: Ordinate_Resolution: Planar_Distance_Units: meters Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: Entity_Type_Definition: Entity_Type_Definition_Source: ARC/INFO Attribute: Attribute_Label: HUC Attribute_Definition: Hydrologic Accounting Unit Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Maximum: Range_Domain_Minimum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: NDVIINC Attribute_Definition: Increase in NDVI Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: NDVIDEC Attribute_Definition: Decrease in NDVI Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: NDVITOT Attribute_Definition: Total Change in NDVI Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: NDVISL Attribute_Definition: NDVI on greater than 3% slopes Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: DEC1ST Attribute_Definition: Decrease in NDVI along 1st order streams Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: INC1ST Attribute_Definition: Increase in NDVI along 1st order streams Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Attribute: Attribute_Label: TOT1ST Attribute_Definition: Total change in NDVI along 1st order streams Attribute_Definition_Source: Attribute_Domain_Values: Range_Domain: Range_Domain_Minimum: Range_Domain_Maximum: Attribute_Measurement_Frequency: None planned Overview_Description: Entity_and_Attribute_Overview: Entity_and_Attribute_Detail_Citation: Not available Distribution_Information: Distributor: Contact_Information: Contact_Person_Primary: Contact_Person: Bruce Jones Contact_Organization: EPA Landscape Ecology Division Contact_Address: Address_Type: Address: U.S. Environmental Protection Agency, Box 93478 City: Las Vegas State_or_Province: Nevada Postal_Code: 89193-3478 Contact_Electronic_Mail_Address: jones.bruce@epamail.epa.gov Metadata_Reference_Information: Metadata_Date: 19980901 Metadata_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Jim Wickham Contact_Organization: Environmental Protection Agency Contact_Address: Address_Type: Address: MD-77B Address: USEPA Mailroom City: Research Triangle Park, NC 27711 State_or_Province: Postal_Code: Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: 19940608 Metadata_Security_Information: Metadata_Security_Classification_System: None Metadata_Security_Classification: Unclassified Metadata_Security_Handling_Description: None