Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: USDA-Natural Resources Conservation Service, Tennessee
Publication_Date: January 10, 2008
Title: Tennessee Sub-Watershed Boundaries
Geospatial_Data_Presentation_Form: Vector Digital Data, Map
Series_Information:
Series_Name: NRCS Tennessee HUA Sub Watershed Layer
Issue_Identification: Version 1
Publication_Information:
Publication_Place: Murfreesboro Tennessee
Publisher: USDA Natural Resources Conservation Service
Online_Linkage: http://www.ncgc.nrcs.usda.gov/branch/gdb/products/watershed/index.html
Description:
Abstract:
This coverage contains Hydrologic Unit Areas and their associated coding for Tennessee watersheds. The boundaries of these areas were hand delineated at a scale of 1:24,000 over 7.5” quads, then digitized on screen over drg-es obtained from the Tennessee Valley Authority in 1995.
Purpose:
These watershed and sub-watershed hydrologic unit boundaries provide a uniquely identified and uniform method of subdividing large drainage areas. The smaller sized hydrologic units are useful in many programs supported by the Natural Resources Conservation Service and other public and private entities involved in natural resource work.
This data set is intended as a tool for water-resource management and planning activities, particularly for site-specific and localized studies which require the amount of detail provided by this data.
Supplemental Information:
This data set was developed between 1995 to 1999 following National NRCS procedures as outlined in National Instruction Number 170-304 and its related updates.
The HUA boundaries were first delineated by hand on USGS 7.5', 1:24K topographic maps of various dates. These lines were checked by local NRCS field personal, local groups, units of government or other county level entities that had an interest in the data.
Next the maps were submitted to the NRCS GIS office in Murfreesboro, Tennessee for further review and editing. The line work was then digitized on screen over DRG's produced by the Tennessee Valley Authority. The base map dates of the DRG's were the latest version available as of 1994 when the DRG production was completed by TVA. The HUA boundaries were digitized in Grass 4.13, in a NAD 83 UTM Zone 16 or 17 mapset. HU Areas in UTM Zone 15 (extreme SW Tenn.) were digitized as if they were in UTM Zone 16. On screen digitizing scales were normally around 1:7500, but ranged from 1:5000 to 1:15000. This exceeded the stated accuracy of the DRGs but was done to produce a more visually appealing line and does not imply that the data contained is of that accuracy. This HUA line work is certified to be accurate at 1:24000. Split Zone Counties were digitized in their predominant zone.
After on screen digitizing was finished all line work was plotted to scale (1:24000) over DRG's and again checked and edited. Then HU coding was assigned as per National Instruction 170-304. The data was then exported using the Grass command v.out.arc. It was imported into ARC UTM-NAD83 projections and merged into this one dataset called TN_WBD_draft.e00 for official release and distribution. This e00 file contains and is in a UTM Nad83 projection. Quality checks and edits were made to ensure the data was still accurate at 1:24000 after conversion to ARC e00 format.
While the HUA line work was being digitized the county lines and state for Tennessee was also digitized from the DRG's. This data is available from NRCS-TN also and meets the same standards as the HUA dataset.
Data was projected to GCS GRS 1980 in 2007-08. A major Quality Review was initiated using ArcGIS 9.1 as well as ArcInfo8.3 for ancillary AML attribute population scripts. The new .e00 file name is TN_hu12.e00. The data was submitted for review by ftp to USGS on March 27, 2008.
* NOTE: 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 metadata file is intended to document the data set in non-proprietary form, some reference to various GIS licensed software products may occur and is for reference only.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: Janurary 10, 2000
Currentness_Reference: Publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: As needed
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: 90:37:14W
East_Bounding_Coordinate: 81:33:06W
North_Bounding_Coordinate: 36:40:54N
South_Bounding_Coordinate: 34:51:10N
Keywords:
Theme:
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: hydrologic
Theme_Keyword: watershed
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: Tennessee
Access_Constraints: None
Use_Constraints:
The U.S. Department of Agriculture, Natural Resources Conservation Service should be acknowledged as the data source in products derived from these data. The data should not be used at scales greater than 1:24,000. This is public information and may be interpreted by organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the Natural Resources Conservation Service any authority for the decisions they make. The Natural Resources Conservation Service will not perform any evaluations of these maps or purposes related solely to State or local regulatory programs.
Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can cause misrepresentation of the data. If enlarged, the maps will not include the fine detail that would be appropriate for mapping at the small scale. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of this data.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Tennessee Natural Resource Conservation Service
Contact_Person: Kevin Davis
Contact_Address:
Address_Type: Business
Address: 1171 Nashville Hwy
City: Lewisburg
State_or_Province: TN
Postal_Code: 37091
Contact_Voice_Telephone: 931-359-6268 x102
Contact_Electronic_Mail_Address: Kevin.Davis@tn.usda.gov
Contact_Instructions: Please email questions and requests.
Data_Set_Credit: Michael L. Hart, NRCS
Native_Data_Set_Environment:
Sun Solaris 4.13, Sun Sparc 20
USACRL Grass version 4.13
Cross_Reference:
Citation_Information:
Originator: Soil Conservation Service
Publication_Date: 1991
Title: Hydrologic Unit Map and Sub-Watersheds State of Tennessee
Geospatial_Data_Presentation_Form: Map
Series_Information:
Series_Name: Hydrologic Unit Map -- 1991
Issue_Identification: 1991
Publication_Information:
Publication_Place: Fort Worth, Texas
Publisher: U.S.D.A. Soil Conservation Service
Online_Linkage: http://www.ftw.nrcs.usdas.gov
Data_Quality_Information:
Logical_Consistency_Report:
Polygon and chain-node topology are present. The tests of logical consistency are performed using vendor software. All internal polygons were tested for closure with vendor software and were checked on hard copy plots.
There are no unclosed polygons, intersections without nodes, or polygons without labels or with more than one label. Arc/Info's topological correction program CLEAN was used to correct intersections without nodes, identify unclosed polygons and remove duplicate lines with the same beginning and ending nodes. All sliver polygons were removed either using eliminate, merge or manually in ArcEdit.
Completeness_Report: A Hydrologic Unit (HU) is an area of land upstream from a specific point on a stream (designated as the outlet). The HU boundary includes all the source area that could contribute surface water runoff directly and indirectly to the outlet. For the purposes of this effort, HU areas (not always pure hydrologic units) are grouped together depending upon their size. Areas grouped together in size units between 40,000 and 250,000 acres are referred to as watersheds and assigned an appropriate eleven (11) digit code. The watersheds are then hydrologically subdivided into sub-watersheds and assigned a fourteen (14) digit code. The sub-watersheds typically range between 3,000 and 40,000 acres in size, but a small percentage may fall outside this range for various local reasons.
All fields for all polygons in the .pat are attributed. Some polygons in the Ncontrb_a field might have a 0 value. All fields for the lines in the .aat are attributed. The lines adjacent to the universal polygon are attributed with a 0 for the hu_level. These cannot be attributed until the adjacent states complete their linework at which point the highest level of hydrologic unit can be determined.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: The accuracy of this data is based on contour information derived from the DRG's produced by the Tennessee Valley Authority. The DRG's used to digitize the HU boundaries in this project were certified to meet National Federal Map Accuracy Standards. HU boundary interpretations may be supplemented with site visits or local knowledge of HU boundaries; needed to determine unusual or difficult terrain areas or due to drainage pattern changes by man's activities. The differences in positional accuracy between the true hydrologic unit boundaries and their digitized map locations are unknown.
The WBD was produced using Enhanced Digital Raster Graphics (DRG-Es) digital images as source map. Data completeness for DRG files reflect content of the source graphic and may therefore is reflected in the completeness and accuracy of the WBD. The map was digitized from USGS 1:24,000-scale digital raster graphic base maps, with an inherited error of +/- 40 feet according to USGS National Map Accuracy Standards. Digitized line locations were held to the +/- 40 foot accuracy standards by ensuring that all lines were within a 12 meter buffer of where visual interpretation put the actual boundary. Any lines outside the buffer were corrected. It is estimated that the errors detected were less than 10%. It should be noted that while general rules of hydrology were used (i.e. water flows downhill), the location of boundaries is still somewhat subjective as the 1:24,000-scale DRG-E do not always provide enough information for identifying the location of the boundaries. In these instances group consensus was used. Please refer to the methods section for more details on watershed delineation rules. Unquantifiable errors may be associated with coordinate shift (fuzzy tolerance was set to 0.000000001 meters, double precision). The default was used for all other ArcEdit tolerances. As with the original DRGs, DRG-E is cast in the Universal Transverse Mercator projection and is referenced to the NAD27 datum. When the drg-es are used in the NAD83 datum the alternate world files only approximate the NAD83 by shifting the coordinates of the imagery. The total error introduced using this shift is less than 2 meters for all DRG-E imagery.
Attribute_Accuracy:
Attribute_Accuracy_Report:
Polygon identifiers are manually assigned and checked with the original base map using the attribute file.
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: US Geological Survey
Publication_Date: varied
Title: Enhanced Digital Raster Graphic
Geospatial_Data_Presentation_Form: map
Online_Linkage:
http://lighthouse.nrcs.usda.gov/gateway/gatewayhome.html
Source_Scale_Denominator: 24,000
Type_of_Source_Media: online
Source_Time_Period_of_Content: unknown
Time_Period_Information: unknown
Range_of_Dates/Times: unknown
Beginning_Date: unknown
Ending_Date: unknown
Source_Currentness_Reference: map delineation
Source_Citation_Abbreviation: DRG24
Source_Contribution: USGS
Process_Step:
Process_Description: Level 6 (12-digit) watersheds were delineated within a nested hierarchical structure using the existing Level 5 (11-digit) watershed delineation as a starting framework. The 11-digit code was reduced to 10 digits to conform to the new Federal Standards for the Delineation of Hydrologic Units Boundaries, by dropping the zero in the last position.
The typical size of a level 6 watershed is 10,000 to 40,000 acres. Not all watersheds exceeding 10,000 acres are delineated. Only those watersheds that show some unique cultural, physical, or logical significance were included in the data.
The order of precedence for establishing the pour point of a sub-watershed is: (1) at the outlet of a lake or pond; (2) at a confluence; (3) at some topographic feature, such as a natural gap in topography; (4) at a dam; (5) at a stream gauging station.
Source_Used_Citation_Abbreviation: DRG24
Process_Date: 20080327
Process_Step: TN02
Process_Description: USGS Edits to Tennessee to eliminate duplicate HUC12 codes.
Source_Used_Citation_Abbreviation:
Process_Date: 20081130
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition: GCS_North_America_1983
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: TN_Hu12.aat
Entity_Type_Definition: identifies watershed boundaries
Entity_Type_Definition_Source: n/a
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: FNODE#
Attribute_Definition: Internal node number for the beginning of an arc (from-node).
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Whole numbers that are automatically generated.
Attribute:
Attribute_Label: TNODE#
Attribute_Definition: Internal node number for the end of an arc (to-node).
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Whole numbers that are automatically generated.
Attribute:
Attribute_Label: LPOLY#
Attribute_Definition: Internal node number for the left polygon.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Whole numbers that are automatically generated.
Attribute:
Attribute_Label: RPOLY#
Attribute_Definition: Internal node number for the right polygon.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Whole numbers that are automatically generated.
Attribute:
Attribute_Label: LENGTH
Attribute_Definition: Length of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: TN_Hu12#
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: TN_Hu12_ID
Attribute_Definition: User-defined feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: HU_LEVEL
Attribute_Definition: The highest hydrologic unit level (smallest number) for the line (arc) represented by the record
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: LINESOURCE
Attribute_Definition: The base map source(s) used to delineate at 1:24,000 scale
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values: DRG24
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: META_ID
Attribute_Definition: Metadata ID is a code that identifies which metadata file applies to the arc
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values: TN01
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Detailed_Description:
Entity_Type:
Entity_Type_Label: TN_Hu12.pat
Entity_Type_Definition: polygons identify watershed boundaries
Entity_Type_Definition_Source: n/a
Attribute:
Attribute_Label: FID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: AREA
Attribute_Definition: Area of feature in internal units squared.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: PERIMETER
Attribute_Definition: Perimeter of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Positive real numbers that are automatically generated.
Attribute:
Attribute_Label: TN_Hu12 #
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label:TN_Hu12-ID
Attribute_Definition: User-defined feature number.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: HUC_8
Attribute_Definition: A unique 8-digit code from the USGS map series "Hydrologic Unit Maps" was created. The same number was used in every record that pertains to a sub watershed that resides within the same 8-digit sub-basin.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HUC_10
Attribute_Definition: This field provides a unique 10-digit code for each watershed derived from the 8-digit code. This same number was used in every record that pertains to a sub watershed that resides within the same 10-digit watershed.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HUC_12
Attribute_Definition: This field provides a unique 12-digit code for each sub watershed derived from the 10-digit code.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: ACRES
Attribute_Definition: Area of sub watershed including non-contributing areas calculated to acres as a whole number, no decimals.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: STATES
Attribute_Definition: The "States" field includes the names of all state(s) that the sub watershed falls within.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: NCONTRB_A
Attribute_Definition: Drainage areas that do not flow toward the outlet of any hydrologic unit are considered non-contributing.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_10_DS
Attribute_Definition: The 10-digit code of the 5th level hydrologic unit that is receiving the majority of the flow from the watershed that the 6th level HU falls within. Outlets created by ditching or other artificial drainage were not considered for this field.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_10_NAME
Attribute_Definition: A unique name for each 5th level hydrologic unit that relates to the major water feature within the polygon or the major water body it contributes to
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_10_MOD
Attribute_Definition: This field identifies interbasin transfers (IT), dams at outlet (DM), etc. that modify natural overland flow as modifications are identified from most significant to least significant modification(s). Hydrologic units with no modification are marked with NM.
Attribute_Definition_Source: Modification by 1 to the Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_10_TYPE
Attribute_Definition: This field identifies the type of watershed.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_12_DS
Attribute_Definition: The 12-digit code of the 5th level hydrologic unit that is receiving the majority of the flow from the watershed that the 6th level HU falls within. Outlets created by ditching or other artificial drainage were not considered for this field.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_12_NAME
Attribute_Definition: A unique name for each 6th level hydrologic unit that relates to the major water feature within the polygon or the major water body it contributes to
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_12_MOD
Attribute_Definition: This field identifies interbasin transfers (IT), dams at outlet (DM), etc. that modify natural overland flow as Modifications are identified from most significant to least significant modification(s). Hydrologic units with no modification are marked with NM.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Attribute:
Attribute_Label: HU_12_TYPE
Attribute_Definition: This field identifies the type of watershed.
Attribute_Definition_Source: Federal Standards for Delineation of Hydrologic Unit Boundaries
Attribute_Domain_Values:
Codeset_Domain:
Codeset_Name: Federal Standards for the Delineation of Hydrologic Unit Boundaries
Codeset_Source: Please refer to the Entity and Attribute Overview for valid values
Overview_Description:
Entity_and_Attribute_Overview:
This is a description of attributes by field from the Federal Standards for Delineation of Hydrologic Unit Boundaries
1) Polygon attributes
Huc_8: Eight Digit Hydrologic Unit Code - (REQUIRED)
Unique 8-digit codes from the USGS map series "Hydrologic Unit Maps". The same number was used in every record that pertains to a sub watershed that resides within the same 8-digit sub-basin. Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion.
Huc_10: Ten Digit Hydrologic Unit Code - (REQUIRED)
This field provides a unique 10-digit code for each watershed. This same number was used in every record that pertains to a sub watershed that resides within the same 10-digit watershed. Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion.
Huc_12: Twelve Digit Hydrologic Unit Code - (REQUIRED)
This field provides a unique 12-digit code for each sub watershed. Numbers were assigned in an upstream to downstream fashion. Where no downstream/upstream relationship could be determined numbers were assigned in a clockwise fashion.
Acres: Acres - (REQUIRED)
Area of sub watershed including non-contributing areas calculated to acres as a whole number, no decimals. The "Acres" field was calculated from the "Area" field.
States: States - (REQUIRED)
The "States" field includes the names of all state(s) that the sub watershed falls within. The 2-digit postal abbreviation in upper case and in alphabetical order was used, separated with a comma.
Ncontrb_a: Non-Contributing Area - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
Drainage areas that do not flow toward the outlet of any hydrologic unit are considered non-contributing. If a non-contributing area is on the boundary between two or more hydrologic units, the non-contributing area is associated with the hydrologic unit adjacent to the low point on the boundary. This attribute should be the total of the non-contributing areas within a hydrologic unit calculated in acres.
Hu_10_ds: Fifth Level Downstream Hydrologic Unit Code - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
This field has the 10-digit code of the 5th level hydrologic unit that is receiving the majority of the flow from the watershed that the 6th level HU falls within. Outlets created by ditching or other artificial drainage were not considered for this field. If an HU flows into an ocean or the Gulf of Mexico, this field was populated with "OCEAN" and if a HU flows into one of the Great Lakes the term "LAKE" was used. If a HU flows across international borders, "CANADA" or "MEXICO" was used depending on which country the HU drains into. If an HU is a closed basin, then the term "CLOSED BASIN” was used.
Hu_10_name: Fifth Level Hydrologic Unit Name - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
This field used officially recognized names only. This field was populated by following the directions in subsection 6.3 "Watershed and Sub watershed Naming Protocol". The name used to attribute the watershed was used only once within a 4th level unit.
Hu_10_mod: Fifth Level Hydrologic Unit Modifications - (REQUIRED)
This field identifies any type of modifications to natural overland flow that alters the location of the hydrologic unit boundary for a 10-digit watershed. This field shows the most significant to least significant modification(s) to the watershed boundary. One or more of the following abbreviations was used.
SC - Stormwater Canal or Drainage Canal
ID - Irrigation Ditch
IT - Interbasin Transfer
BC - Barge Canal or Navigation Canal
SD - Stormwater Ditch
PD - Pipe Diversion
CD - Channel Diversion
NC - Noncontributing Area
KA - Karst
LE - Levee
NM - No Modifications
OC - Overflow Channel or Flume
DM - Dam at outlet or HU boundary
GC - General Canal/Ditch
PS - Pumping Station
DD - Drainage Ditch
SI - Siphon
AD - Aqueduct
RS - Reservoir
TF - Transportation Feature (road, railroad, docks etc.)
GF - Ground-Water Flow
MA - Mining Activity
UA - Urban Area
GL - Glacier
IF - Ice Field
OF - Overbank Flow
OT - Other
Hu_10_type: Fifth Level Hydrologic Unit Type - (REQUIRED)
This field was populated with the hydrologic unit type from the list provided that most closely identifies the watershed.
S - "Standard" hydrologic unit - Any land HU with drainage flowing to a single outlet point, excluding non-contributing areas. This includes areas or small triangular wedges between adjacent HU's that remain after classic hydrologic units are delineated. Some examples include "true", "classic", "composite", and "remnant" hydrologic units.
C - "Closed Basin" hydrologic unit - A drainage area that is 100% non-contributing. This means all surface flow is internal, no overland flow leaves the hydrologic unit through the outlet point.
F - "Frontal" hydrologic unit - Areas along the coastline of lakes, oceans, bays, etc. that have more than one outlet. These HU's are predominantly land with some water areas at or near the outlet(s).
W - "Water" hydrologic unit - Hydrologic units that are predominantly water with adjacent land areas, ex. lake, estuaries, and harbors.
I - "Island" hydrologic unit - A hydrologic unit that is one or more islands and adjacent water out to the toe of the shore face.
U - "Unclassified" hydrologic unit - A hydrologic unit that can't be defined or doesn't fit into one of the types that have been listed.
Hu_12_ds: Sixth Level Downstream Hydrologic Unit Code - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
This field was populated with the 12-digit code of the 6th level hydrologic unit that is receiving the majority of the flow from the sub watershed. Outlets created by ditching or other artificial drainage were not considered for this field. If a HU flows into an ocean or the Gulf of Mexico it was populate with "OCEAN" and if a HU flows into one of the Great Lakes the term "LAKE" was used. If a HU flows across international borders, "CANADA" or "MEXICO" was used depending on which country the HU drains into. If an HU is a closed basin, this field was populated with the term "CLOSED BASIN".
Hu_12_name: Sixth Level Hydrologic Unit Name - (FIELD REQUIRED, ATTRIBUTES OPTIONAL)
Officially recognized names were used in this field. This field was populated by following the directions in subsection 6.3 "Watershed and Sub watershed Naming Protocol". The name used to attribute the sub watershed was used only once within a 4th level unit.
Hu_12_mod: Sixth Level Hydrologic Unit Modifications - (REQUIRED)
This field identifies any type of man-made modification(s) to natural overland flow that alters the location of the hydrologic unit boundary for a 12-digit sub watershed. One or more of the following abbreviations was chosen for this field.
SC - Stormwater Canal or Drainage Canal
ID - Irrigation Ditch
IT - Interbasin Transfer
BC - Barge Canal or Navigation Canal
SD - Stormwater Ditch
PD - Pipe Diversion
CD - Channel Diversion
NC - Noncontributing Area
KA - Karst
LE - Levee
NM - No Modifications
OC - Overflow Channel or Flume
DM - Dam at outlet or HU boundary
GC - General Canal/Ditch
PS - Pumping Station
DD - Drainage Ditch
SI - Siphon
AD - Aqueduct
RS - Reservoir
TF - Transportation Feature (road, railroad, docks etc.)
GF - Ground-Water Flow
MA - Mining Activity
UA - Urban Area
GL - Glacier
IF - Ice Field
OF - Overbank Flow
OT - Other
Hu_12_type: Sixth Level Hydrologic Unit Type - (REQUIRED)
This field was populated with the hydrologic unit type from the list provided that most closely identifies the sub watershed.
S - "Standard" hydrologic unit - Any land HU with drainage flowing to a single outlet point, excluding non-contributing areas. This includes areas or small triangular wedges between adjacent HU's that remain after classic hydrologic units are delineated. Some examples include "true", "classic", "composite", and "remnant" hydrologic units.
C - "Closed Basin" hydrologic unit - A drainage area that is 100% non-contributing. This means all surface flow is internal, no overland flow leaves the hydrologic unit through the outlet point.
F - "Frontal" hydrologic unit - Areas along the coastline of lakes, oceans, bays, etc. that have more than one outlet. These HU's are predominantly land with some water at or near the outlet(s).
W - "Water" hydrologic unit - Hydrologic units that are predominantly water with adjacent land areas, ex. lake, estuaries.
I - "Island" hydrologic unit - A hydrologic unit that is one or more islands and adjacent water out to the toe of the shore face.
U - "Unclassified" hydrologic unit - A hydrologic unit that can't be defined or doesn't fit into one of the types that have been listed.
2) Line attributes
Hu_level: Hydrologic Unit Level - (REQUIRED)
This field provides the means to create cartographically pleasing maps. This field is populated with the highest hydrologic unit level (smallest number) for the line (arc) represented by the record. The attribute was recorded using numbers 1 through 6 representing each level with 1 being the highest and 6 the lowest level. An example would be if a line represents a region, subregion, basin, subbasin, watershed, and sub watershed boundary, then this cell was populated with a 1 (Region). Below is a list of numbers used for each level.
Level Digit# Name
1 2 Region
2 4 Subregion
3 6 Basin
4 8 Subbasin
5 10 Watershed
6 12 Sub watershed
Linesource: Line Spatial Data Source - (REQUIRED)
The Linesource indicates the base map source(s) used to delineate at 1:24,000 scale. The field was populated using one of the standardized code(s) listed below. If more than one code was used, then a comma was used to separate the codes.
TOPO24 - Delineation from hardcopy 1:24,000 scale topographic maps
TOPO25 - Delineation from hardcopy 1:25,000 topographic maps, only Alaska and Caribbean
TOPO63 - Delineation from hardcopy 1:63,360 topographic maps, only Alaska and Caribbean
DRG24 - Delineation from 1:24,000 scale Digital Raster Graphics
DRG25 - Delineation from 1:25,000 Digital Raster Graphics, only Alaska and Caribbean
DRG63 - Delineation from 1:63,360 Digital Raster Graphics, only Alaska and Caribbean
DEM10 - Derived from 10 meter Digital Elevation Model
DEM30 - Derived from 30 meter Digital Elevation Model
NED30 - Derived from 30 meter National Elevation Dataset Model
EDNA30 - (formally NED-H), derived from 30 meter Elevation Derivatives for National
Applications
BATH” scale" (ex. BATH24) - Interpreted from NOAA 1:24,000 scale bathymetric data
HYPSO "scale" (ex. HYPSO24) - Delineated from 1:24,000 scale contour data
ORTHO "scale" (ex. ORTHO12) - Interpreted from 1:12,000 scale Ortho-imagery
DEDEM10 - Drainage enforced 10 meter Digital Elevation Model
DEDEM30 - Drainage enforced 30 meter Digital Elevation Model
GPS - Derived from Global Positioning System
LIDAR - Derived from LIDAR
IFSAR - Derived from IFSAR data
OTH - Other
UNK - Unknown
All other reference and source maps not listed should be noted in the metadata.
Meta_id: Metadata ID Number - (REQUIRED)
The Metadata ID is a code that identifies which metadata file applies to the arc. In most cases there is only one metadata file. However, in some cases more than one metadata file was used to identify different groups and/or procedures used to produce the lines. The metadata ID is a 4-character code starting with the 2-letter state postal code, followed by a 2-digit sequence number. For example "OK01", "ID02", etc
Entity_and_Attribute_Detail_Citation: Federal Standard for Delineation of Hydrologic Unit Boundaries
Distribution_Information:
Distributor:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Kevin Davis
Contact_Organization: Tennessee Natural Resources Conservation Service
Contact_Address:
Address_Type: mailing address
Contact_Address:
Address_Type: Business
Address: 1171 Nashville Hwy
City: Lewisburg
State_or_Province: TN
Postal_Code: 37091
Contact_Voice_Telephone: 931-359-6268 x102
Contact_Instructions: please e-mail with data requests.
Distribution_Liability: The distributor shall not be held liable for improper or incorrect use of this data, based on the description of appropriate/inappropriate uses described in this metadata document. It is strongly recommended that this data is directly acquired from the distributor and not indirectly through other sources which may have changed the data in some way. These data should not be used at scales greater than 1:24,000 for the purpose of identifying hydrographic watershed boundary feature locations in Tennessee. NRCS makes no claims for the data's suitability for other purposes. USGS should be acknowledged as the data source in products derived from these data. The Tennessee Watershed Boundary Dataset is public information and may be interpreted by all organizations, agencies, units of government, or others based on needs; however, they are responsible for the appropriate application of the data. Federal, State, or local regulatory bodies are not to reassign to the USGS or the Natural Resources Conservation Service any authority for the decisions they make. The Natural Resources Conservation Service will not perform any evaluations of these maps or purposes related solely to State or local regulatory programs. Photographic or digital enlargement of these maps to scales greater than that at which they were originally delineated can result in misrepresentation of the data. If enlarged, the maps will not include the fine detail that would be appropriate for mapping at the small scale. Digital data files are periodically updated. Files are dated, and users are responsible for obtaining the latest version of the data from the source distributor.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ftp
Transfer_Size: 21 mg
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: unknown
Fees: none
Metadata_Reference_Information:
Metadata_Date: January 10, 2000
Metadata_Review_Date: January 10, 2000
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S.D.A. NRCS-TN
Contact_Person: Michael L. Hart
Contact_Position: Geographis Information Specialist
Contact_Address:
Address_Type: mailing and physical address
Address: 410 New Salem Road, Suite 105
City: Murfreesboro
State_or_Province: TN
Postal_Code: 37129
Country: USA
Contact_Voice_Telephone: 615-893-9295
Contact_Facsimile_Telephone: 615-893-9136
Contact_Electronic_Mail_Address: mhart@tn.nrcs.usda.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