The following references are cited in the metadata for OHIN_ECO:
"Bailey, R.G., P.E. Avers, T. King, adn W.H. McNab. 1994. Ecoregions and subregions of the United States (map) (supplementary table of map unit descriptions compiled and edited by McNab and Bailey,) Washington, D.C., U.S. Department of Agriculture - Forest Service, scale 1:7,500,000.
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 Laboratory, Corvallis,OR. 152p.
Griffith, G.E., J.M. Omernik, T.F. Wilton, and S.M. Pierson. 1994. Ecoregion and subregions of Iowa - a framework for water quality assessment and management. The Journal of the Iowa Academy of Sciences 101(1):5-13.
Omernik, J.M. 1987. Ecoregions of the conterminous United States. Map supplement.) Annals of the Association of American Geographers. v.77 no. 1, p. 118-125, scale 1:7,500,000.
Omernik, J.M. 1995. Ecoregions: a 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.
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. 1997. Level III Ecoregions of the Continental United States, Map M-1 (revision of Omernik, 1987). Corvallis, Oregon. U.S. Environmental Protechtion Agency - National Health and Environmental Effects Research Laboratory.
Wilken, E. 1986. Terrestrial ecozones of Canada. Environment Canada Ecological Land Classification Series No. 19. Ottawa, Canada. 26p."
"The ecoregions shown here have been derived from Omernik (1987) and fr refinements of Omernik's framework that have been made for other projects. These ongoing or recently completed projects, conducted in collaboration with the U.S. EPA regional offices and with state resource management agencies, involve refining ecoregions, defining subregions, and locating sets of reference sites. Designed to serve as a spatial framework for environmental resource management, ecoregions denote areas within which ecosystems (and the type, quality, and quantity of environmental resources) are generally similar. The most immediate needs are to develope regional biological criteria and water quality standards and to set management goals for nonpoint source pollution.
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 (Wiken 1986; Omernik 1987, 1995). 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. Because of possible confusion with other meanings of terms for different levels of ecologic regions, a Roman numeral classification scheme has been adopted for this effort. Level I is the coarsest level, dividing North America into nine ecological regions whereas at Level II the continent is subdivided into 32 classes. Level III is the hierarchical level shown on this map. For portions of the United States the ecoregions have been further subdivided to level IV. The applications of the ecoregions are explained in Gallant et al. (1989) and in reports and publications from the state and regional projects. For additional information, contact James M. Omernik, U.S. EPA National Health and Environmental Effects Laboratory (NHEERL), 200 SW 35th St., Corvallis, OR 97333 (phone: 541-754-4458)."
"Assist managers of aquatic and terrestrial resources in understanding regional patterns of of the realistically attainable quality of these resources."
This data set was compiled by Indiana University, Indiana Geological Survey, using data believed to be accurate; however, a degree of error is inherent in all data. This product is distributed "AS-IS" without warranties of any kind, either expressed or implied, including but not limited to warranties of suitability of a particular purpose or use. No attempt has been made in either the designed format or production of these data to define the limits or jurisdiction of any federal, state, or local government.
These data are intended for use only at the published scale or smaller and are for reference purposes only. They are not to be construed as a legal document or survey instrument. A detailed on-the-ground survey and historical analysis of a single site may differ from this data.
It is requested that the Indiana Geological Survey be cited in any products generated from this data. The following source citation should be included: [ECOREGIONS_USGS_IN: Ecoregions, Levels III and IV, Indiana (U.S. Geological Survey, 1:250,000, Polygon Shapefile)]
WARRANTY
Indiana University, Indiana Geological Survey warrants that the media on which this product is stored will be free from defect in materials and workmanship for ninety (90) days from the date of acquisition. If such a defect is found, return the media to Publication Sales, Indiana Geological Survey, 611 North Walnut Grove, Bloomington, Indiana 47405-2208, and it will be replaced free of charge.
LIMITATION OF WARRANTIES AND LIABILITY
Except for the expressed warranty above, the product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product users indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product.
The following is excerpted from metadata for OHIN_ECO:
"for use at 1:250,000 or smaller scales."
"Attribute accuracy is described, where present, with each attribute defined in the Entity and Attribute Section."
"Polygon and chain-node topology present."
"1) All ecoregion and subregion 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 for each polygon.
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."
"1) All ecoregion and subregion 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 for each polygon.
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."
The following is excerpted from the metadata for OHIN_ECO: "ECO - ecoregion ID code
54 Central Corn Belt Plains
54a Illinois/Indiana Praries
54b Chicago Lake Plain
54c Kankakee Marsh
54d Kankakee Sand Area
55 Eastern Corn Belt Plains
55a Clayey, High Lime Till Plains
55b Loamy, High Lime Till Plains
55c Mad River Interlobate Area
55d Pre-Wisconsinan Drift Plains
55e Darby Plains
55f Whitewater Interlobate Area
56 Southern Michigan/Northern Indiana Drift Plains
56a Lake Country
56b Elkhart Till Plains
56c Middle Tippecanoe Plains
56d Michigan Lake Plain
57 Huron/Erie Lake Plains
57a Maumee Lake Plains
57b Oak Openings
57c Paulding Plains
57d Marblehead Drift/Limestone Plain
61 Erie/Ontario Drift and Lake Plain
61a Erie Lake Plain
61b Mosquito Creek/Pymatuning Lowlands
61c Low Lime Drift Plain
61d Erie Gorges
61e Summit Interlobate Area
70 Western Allegheny Plateau
70a Permian Hills
70b Monongahela Transition Zone
70c Pittsburgh Low Plateau
70d Lower Scioto Dissected Plateau
70e Unglaciated Upper Muskingum Basin
70f Ohio/Kentucky Carboniferous Plateau
71 Interior Plateau
71a Crawford Uplands
71b Mitchell Plain
71c Norman Upland
71d Northern Bluegrass
72 Interior River Lowland
72a Wabash Bottomlands
72b Glaciated Wabash Lowlands
72c Southern Wabash Lowlands"
WARRANTY
Indiana University, Indiana Geological Survey warrants that the media on which this product is stored will be free from defect in materials and workmanship for ninety (90) days from the date of acquisition. If such a defect is found, return the media to Publication Sales, Indiana Geological Survey, 611 North Walnut Grove, Bloomington, Indiana 47405-2208, and it will be replaced free of charge.
LIMITATION OF WARRANTIES AND LIABILITY
Except for the expressed warranty above, the product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product users indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product.