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nv_omer_eco4

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: US Environmental Protection Agency
Publication_Date: 2003
Title: Level III and IV Ecoregions of Nevada (nv_omer_eco4)
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage: N/A
Description:
Abstract:
Ecoregions denote areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They are designed to serve as a spatial framework for environmental resource management. Ecoregions are directly applicable to the immediate needs of state agencies, including the selection of regional stream reference sites, the development of biological criteria and water quality standards, and the establishment of management goals for source pollution. They are also relevant to integrated ecosystem management, an ultimate goal of many federal and state resource management agencies. This map depicts revisions and subdivisions of ecoregions, compiled originally at a relatively small scale (USEPA 2000, Omernik 1987). Compilation of this map, performed at the larger 1:250,000-scale, is part of several collaborative projects primarily between the U. S. Environmental Protection Agency (EPA) National Health and Environmental Effects Research Laboratory (NHEERL), the U.S. Department of Agriculture's Natural Resources Conservation Service (NRCS), and state environmental resource agencies. Collaboration and consultation also occurred with other state and federal agencies, including the U.S. Forest Service and U.S. Geological Survey, in an effort to obtain consensus regarding alignments of ecological regions.

The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the patterns and the composition of biotic and abiotic phenomena that affect or reflect differences in ecosystem quality and integrity. These phenomena include geology, physiography, vegetation, climate, soils, land use, wildlife, and hydrology. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical level. A Roman numeral hierarchical scheme has been adopted for different levels of ecological regions. Level I and Level II divide the North American continent into 15 and 52 regions, respectively (Commission for Environmental Cooperation 1997). At Level III, the continental United States contains 104 regions and the conterminous U.S. has 84 ecoregions (U.S. EPA 2000). Level IV is a further subdivision of the Level III ecoregions. Explanation of the methods used to define the ecoregions are given in Griffith et al. (1994, 1997, 2001), Omernik (1995, 2000), and Gallant et al. (1989).

Regional collaborative projects such as these state efforts, where the goal is to reach consensus among resource management agencies, comprise a step in the direction of reaching the objectives of the Memorandum of Understanding for developing a common framework of ecological regions (McMahon et al. 2001). A common spatial framework would allow integrated ecosystem-type resource management across agencies having different responsibilities and interests for the same geographic areas. Reaching that objective requires recognition of the references in the conceptual approaches and mapping methodologies that have been used to develop the most commonly used existing ecoregion-type frameworks, including those developed by the U.S. Forest Service (Bailey and others 1994), the U.S. EPA (Omernik 1987, 1995), and the NRCS (U.S. Department of Agriculture - Soil Conservation Service 1981). As each of these frameworks is further developed, the differences between them are becoming less. Collaborative projects at the state and regional level, where agreement can be reached among multiple resource management agencies, is a step in the direction of attaining commonality and consistency in ecoregion frameworks for the entire nation.

The purpose of producing this map of Level III and IV Ecoregions of EPA Nevada is to: 1) highlight the current status and progress of ecoregion projects; 2) illustrate the hierarchical nature of the ecoregions; and 3) promote discussion and debate about the location of boundaries, level of consistency from state to state, and areas in need of revision. Comments and suggestions should be addressed to Sandy Bryce, Dynamac Corp., 200 SW 35th Street, Corvallis, OR 97333, (541) 754-4788, email: sandra.bryce@epa.gov., or to James Omernik, U.S. EPA - NHEERL, 200 SW 35th Street, Corvallis, OR 97333, (541) 754-4458, email: omernik.james@epa.gov.

Purpose:
Assist managers of aquatic and terrestrial resources in understanding the regional patterns of the realistically attainable quality of these resources.
Supplemental_Information:
Procedures_Used: 1) All ecoregion delineations are digitized from the U.S.G.S. 1:250,000 base maps. Prior to digitizing each base map must be initialized to orient the map and relate it in geographic coordinates to the surface of the earth. When the registration tics are entered at the start of digitizing a transformation error of <0.003 must be achieved in order to insure a high level of registration accuracy. The person responsible for digital data entry completes a data sheet describing coverage name, date of entry, and whether a topology for the coverage is established.

2) After each 1:250,000 base map has been digitized, a topology for each coverage is established. This function creates unique identities

3) Next each base map is tested for polygon errors through an internal editing function. Errors are corrected for unlabeled polygons, unclosed polygons, or polygons with more than one label. Topology is reestablished for each coverage and tested again until no error are indicated. 4) The digital coverage is then plotted at the same scale as the original base map. This coverage is overlaid on a light table with the original and visually inspected for replication of original lines with digitized lines. Two individuals independently inspect the coverage for accuracy. REFERENCES Bailey, R.G., P.E. Avers, T. King, and W.H. McNab (eds.). 1994. Ecoregions and subregions of the United States (map) (supplementary table of map unit descriptions compiled and edited by W.H. McNab, and R.G. Bailey). U.S. Department of Agriculture-Forest Service, Washington, D.C., scale 1:7,500,000. Commission for Environmental Cooperation. 1997. Ecological regions of North America: toward a common perspective. Commission for Environmental Cooperation, Montreal, Quebec, Canada. 71pp. Gallant, A.L., T.R. Whittier, D.P. Larsen, J.M. Omernik, and R.M. Hughes. 1989. Regionalization as a tool for managing environmental resources. EPA/600/3-89/060. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis,OR. 152p. Griffith, G.E., J.M. Omernik, C.M. Rohm, and S.M. Pierson. 1994. Florida regionalization project. EPA/600/Q-95-002. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, OR. 83p. Griffith, G.E, J.M. Omernik, T.F. Wilton, and S.M. Pierson. 1994. Ecoregions and subregions of Iowa: A framework for water quality assessment and management. The Journal of the Iowa Academy of Sciences 101(1):5-13. Griffith, G.E., J.M. Omernik, and S.H. Azevedo. 1997. Ecoregions of Tennessee. EPA/600/R-97/022. U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR. 51p. Griffith, G.E., J.M. Omernik, and S.H. Azevedo. 1998. Ecoregions of Tennessee. (2 sided color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey, Reston, VA. Scale 1:940,000. Griffith, G.E., J.M. Omernik, J.A. Comstock, and T. Foster. 2001. Ecoregions Georgia. U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR. 48p. Griffith, G.E., J.M. Omernik, J.A. Comstock, S. Lawrence, G. Martin, A. Goddard, V.J. Hulcher, and T. Foster. In press. Ecoregions of Alabama and Georgia. (2 sided color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey, Reston, VA. Scale 1:1,700,000. Griffith, G.E., J.M. Omernik, J.A. Comstock, M.P. Shafale, D.R. Lenat, J.B. Glover, V.B. Shelburne, and W.H. McNab. In prep. Ecoregions of North and South Carolina. (2 sided color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey, Reston, VA. Scale 1:1,600,000. McMahon, G., S.M. Gregonis, S.W. Waltman, J.M. Omernik, T.D. Thorson, J.A. Freeouf, A.H. Rorick, and J.E. Keys. 2001. Developing a spatial framework of common ecological regions for the conterminous United States. Environmental Management 28(3):293-316. O mernik, J.M. 1987. Ecoregions of the conterminous United States. Map Supplement (scale 1:7,500,000). Annals of the Association of American Geographers 77(1):118-125. Omernik, J.M. 1995. Ecoregions: A spatial framework for environmental management. In: Biological Assessment and Criteria: Tools for Water Resource Planning and Decision Making. W.S. Davis and T.P. Simon (eds.). Lewis Publishers, Boca Raton, FL. pp. 49-62. Omernik, J.M., S.S. Chapman, R.A. Lillie, and R.T. Dumke. 2000. Ecoregions of Wisconsin. Transactions of the Wisconsin Academy of Science, Arts and Letters 88(2000):77-103. U.S. Department of Agriculture-Soil Conservation Service, 1981, Land resource regions and major land resource areas of the United States: Agriculture Handbook 296, 156 p. U.S. Environmental Protection Agency. 2000. Level III Ecoregions of the Continental United States, Map M-1 (revision of Omernik, 1987). U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR.

LNTYPE = item representing the Level III or IV Ecoregion line type 4 = level IV ecoregion boundary 3 = level III ecoregion boundary 9 = state boundary Polygon Attributes: ECO = item representing Level III or IV Ecoregion label ECO_NAME = item representing Level III or IV Ecoregion name ECO ECO_NAME 5 Sierra Nevada 5a. Mid-Elevation Sierra Nevada 5b. High Elevation Sierra Nevada 13 Central Basin and Range 13a. Salt Deserts 13b. Shadscale-Dominated Saline Basins 13c. Sagebrush Basins and Slopes 13d. Woodland- and Shrub-Covered Low Mountains 13e. High Elevation Carbonate Mountains 13g. Wetlands 13h. Lahontan and Tonopah Playas 13j. Lahontan Salt Shrub Basin 13k. Lahontan Sagebrush Slopes 13l. Lahontan Uplands 13m. Upper Humboldt Plains 13n. Mid-Elevation Ruby Mountains 13o. High Elevation Ruby Mountains 13p. Carbonate Sagebrush Valleys 13q. Carbonate Woodland Zone 13r. Central Nevada High Valleys 13s. Central Nevada Mid-Slope Woodland and Brushland 13t. Central Nevada Bald Mountains 13u. Tonopah Basin 13v. Tonopah Sagebrush Foothills 13w. Tonopah Uplands 13x. Sierra Nevada-Influenced Ranges 13y. Sierra Nevada-Influenced High Elevation Mountains 13z. Upper Lahontan Basin 13aa. Sierra Nevada-Influenced Semiaried Hills and Basins 14 Mojave Basin and Range 14a. Creosote Bush-Dominated Basins 14b. Arid Footslopes 14c. Mojave Mountain Woodland and Shrubland 14d. Mojave High Elevation Mountains 14e. Arid Valleys and Canyonlands 14f. Mojave Playas 14g. Amargosa Desert 22 Arizona/New Mexico Plateaun 22d. Middle Elevation Mountains 80 Northern Basin and Range 80a. Dissected High Lava Plateau 80b. Semiarid Hills and Low Mountains 80d. Pluvial Lake Basins 80e. High Desert Wetlands 80g. High Lava Plains 80j. Semiarid Uplands 80k. Partly Forested Mountains 80l. Salt Shrub Valleys REVISIONS: Level III and IV ecoregions of Nevada digitized according to interagency delineations. jac 4/2001 Level III and IV ecoregions of Nevada revised. jac/dr 12/2001 Level III and IV ecoregions of Nevada revised. jac 7/2002 QUALITY ASSURANCE: Digitizing for Level III and IV ecoregions of Nevada checked by Sandy Bryce, Dynamac Corp., 4/2001 Revisions to Level III and IV ecoregions of Nevada checked by Sandy Bryce, Dynamac Corp., 12/2001 Revisions to Level III and IV ecoregions of Nevada checked by Sandy Bryce, Dynamac Corp., 7/2002

Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 2004
Currentness_Reference: publication date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -120.978703
East_Bounding_Coordinate: -112.449008
North_Bounding_Coordinate: 42.933014
South_Bounding_Coordinate: 34.302941
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: Level III and IV ecoregions, Nevada
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: Level III and IV Ecoregions of Nevada
Access_Constraints: none
Use_Constraints: none
Security_Information:
Security_Classification_System: none
Security_Classification: UNCLASSIFIED
Security_Handling_Description: none
Native_Data_Set_Environment:
Microsoft Windows 2000 Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 8.2.0.700
Cross_Reference:
Citation_Information:
Originator: Griffith, G.E., J.M. Omernik
Publication_Date: 2003
Title: Ecoregions of Nevada
Edition: v1

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Complete chain
Point_and_Vector_Object_Count: 868
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 503
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 503
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Point
Point_and_Vector_Object_Count: 1700
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Label point
Point_and_Vector_Object_Count: 0

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: Albers Conical Equal Area
Albers_Conical_Equal_Area:
Standard_Parallel: 29.500000
Standard_Parallel: 45.500000
Longitude_of_Central_Meridian: -96.000000
Latitude_of_Projection_Origin: 23.000000
False_Easting: 0.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.000438
Ordinate_Resolution: 0.000438
Planar_Distance_Units: meters
Geodetic_Model:
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:
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Detailed_Description:
Entity_Type:
Entity_Type_Label: nv_omer_eco4.aat
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:
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Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: FNODE#
Attribute_Definition: Internal node number for the beginning of an arc (from-node).
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: TNODE#
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Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: LPOLY#
Attribute_Definition: Internal node number for the left polygon.
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Attribute_Domain_Values:
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Attribute:
Attribute_Label: RPOLY#
Attribute_Definition: Internal node number for the right polygon.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: LENGTH
Attribute_Definition: Length of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: NV_OMER_ECO4#
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: NV_OMER_ECO4-ID
Attribute_Definition: User-defined feature number.
Attribute_Definition_Source: ESRI
Attribute:
Attribute_Label: LNTYPE
Detailed_Description:
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Attribute:
Attribute_Label: FID
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Attribute_Domain_Values:
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Sequential unique whole numbers that are automatically generated.
Attribute:
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Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: AREA
Attribute_Definition: Area of feature in internal units squared.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: PERIMETER
Attribute_Definition: Perimeter of feature in internal units.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
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Attribute:
Attribute_Label: NV_OMER_ECO4#
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: NV_OMER_ECO4-ID
Attribute_Definition: User-defined feature number.
Attribute_Definition_Source: ESRI
Attribute:
Attribute_Label: ECO
Attribute:
Attribute_Label: LEVEL4
Attribute:
Attribute_Label: LEVEL4_NAME
Attribute:
Attribute_Label: LEVEL3
Attribute:
Attribute_Label: LEVEL3_NAME
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Distribution_Information:
Resource_Description: Downloadable Data
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Transfer_Size: 1.087

Metadata_Reference_Information:
Metadata_Date: 20050408
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: U.S. EPA - NHEERL
Contact_Person: James Omernik
Contact_Address:
Address_Type: mailing and physical address
Address: 200 SW 35th Street
City: Corvallis
State_or_Province: Oregon
Postal_Code: 97333
Country: USA
Contact_Voice_Telephone: (541) 754-4458
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

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