Section 1	Identification Information
Originator	Tiger/Line 1995 - US side, Environment Canada/Sensitivity Mapping Program 1996 - Canadian side
Title	Rivers for the Lake Superior Basin
Abstract	This data set consists of lines and arcs taken from Tiger/Line files and Environment Canada to create a basin-wide rivers coverage. This data was clipped with a 50 km buffer of the Lake Superior Drainage basin, and then split into counties for the US side, and kept whole for the Canada side. The coverage displays most major and minor streams and rivers. For the fields 'time period of content and source scale denominator' the US information was used. The Canada information is 1996, and 250000, respectively.
Purpose	A base data layer.
Time Period of Content Date	1995
Currentness Reference	Date of Tiger/Line data and Canada sensitivity mapping program data
Progress	Complete
Maintenance and Update Frequency	As needed
Spatial Extent of Data	Lake Superior Basin, including parts of Minnesota, Michigan, Wisconsin, and Ontario, Canada
Bounding Coordinates	-97.293 -81.564 49.255 41.573
Place Keywords	Minnesota, Michigan, Wisconsin, and Ontario
Theme Keywords	rivers, streams, waterways, hydro
Theme Keyword Thesaurus	None
Access Constraints	None
Use Constraints	None
Contact Person Information	Gerald Sjerven, GIS Specialist Natural Resources Research Institute 5013 Miller Trunk Hwy Duluth, Minnesota 55811 Phone: (218)-720-4388 FAX: (218)-720-4328 E-mail: gsjerven@sage.nrri.umn.edu
Browse Graphic File Name	none available
Browse Graphic File Description
Associated Data Sets
Section 2	Data Quality Information - - - - - - Go back to top
Attribute Accuracy	US side: Topological Properties The attribute accuracy of the TIGER/Line ® files is as precise as the source used during the creation or update of the Census TIGER ® data base. Accuracy statements on the Census TIGER ® data base are based on deductive estimates; no specific field tests for attribute accuracy have been conducted on the files. However, updates or corrections resulting from normal Census Bureau field operations are entered into the Census TIGER ® data base. In addition, quality checks are conducted to verify clerical transcription of data from source materials. Based on past experience, attribute codes match the source materials with less than a two-percent error. The feature network of complete chains (as represented by Record TypesÊ1 and 2) is complete for census purposes. Data users should be aware that on occasion they may not be able to trace a specific feature by name or by CFCC as a continuous line throughout the TIGER/Line ® files without making additional edits. For example, State Highway 32 may cross the entire county. The TIGER/Line ® files will contain com-plete chains in the file at the location of State Highway 32, but the complete chains may individually have one of a collection of local names such as S Elm Street, or Smallville Highway, with or without State Highway 32 as an alternate. The most frequent CFCC for a state highway is A21, but the complete chains at the location of State High-way 32 may have a variety of class codes such as A01, A41, or A21. Recent edits have reduced this problem, but not eliminated it. Boundaries and Geographic Entity Codes The Census Bureau collects and tabulates information for both legal and statistical entities. Record Types 1 and S identify the boundaries and codes for the legal entities reported to the Census Bureau to be legally in effect on January 1, 1995. Record Types 3 and A generally contain the final 1990 census tabulation geographic boundaries and codes for those entities. Most legal boundaries are based on the anno-tations made by local officials in response to the Census Bureau’s Boundary and Annexation Surveys. The USGS maintains the file that is published as FIPS 55. The Census Bureau uses the file for coding American Indian/Alaska Native Areas, county subdivisions, consolidated cities, places, and sub-MCDs. Cooper-atively in 1993, the Census Bureau and the USGS edited the FIPS 55 file to ensure alphabetical sorting and data consistency. As a result, several hundred changes were made to the FIPS 55 codes and related class codes. These corrections, plus codes for new entities, appear in Record Type C where one record shows the codes used in 1990, and one record shows the current FIPS 55 code/class code associated with each change. Other attribute data in the TIGER/Line ® files were gathered from many sources. The Census Bureau’s staff linked the attribute informa-tion to the spatial framework of features. Most procedures for gathering the needed attributes were clerical. The quality of these attributes was ensured by various tests conducted before, during, and after the time that the attribute information was entered into the Census TIGER ® data base. Tests included source material selection and evaluation checks, quality control checks on staff work, independent reviews by local and tribal leaders of maps produced from the Census TIGER ® data base, and staff reviews of computer-performed operations. Canada: Accuracy of geometric representation data is given by the difference between the position of the geometric representation associated with an entity and the real position of the corresponding topographic feature, as measured with respect to the geodetic network. Ancillary data give an indication of the quality of the NTDB topographic data. Among these ancillary data, one will find the accuracy as determined from the data acquisition process.
Logical Consistency	US side: Node-line-area relationships satisfy topological requirements. These requirements include the following: Complete chains must begin and end at nodes. Complete chains must connect to each other at nodes. Complete chains do not extend through nodes. Left and right polygons are defined for each complete chain element and are consistent for complete chains connecting at nodes. Complete chains representing the limits of a file are free from gaps. The Census Bureau performed automated tests to ensure logical consis-tency and limits of file. Some polygons in the TIGER/Line ® files may be so small, the polygon internal point has been manually placed on a node that defines the polygon perimeter. These small polygons have been detected, and corrections will be incorporated in the Census TIGER ® data base in the future. The Census Bureau uses its internally developedGeographic Update System to enhance and modify spatial and attribute data in the Census TIGER ® data base. The Census TIGER ® data base has three generations of currency in geo-graphic areas. These are generally the previous census areas, current areas, and the next census areas. The boundaries of geographic areas are affected by the location, type, and number of areas. To prepare for the 2000 census, those features used only as boundaries in the 1980 census were deleted. The deletions lowered the overall count of complete chains and polygons. Standard geographic codes, such as FIPS codes for states, counties, munic-ipalities, and places, are used when encoding spatial entities. The Census Bureau performed spatial data tests for logical consistency of the codes during the compilation of the original Census TIGER ® data base files. Most of the codes themselves were provided to the Census Bureau by the USGS, the agency responsible for maintaining FIPS 55. Canada side: None available
Completeness	US side: The GBF/DIME-Files and the USGS’s DLG were the two main sources of spatial attribute data. Data for a given category contain attribute codes that reflect the information portrayed on the original source. The TIGER/Line ® files also use the Census Bureau’s internal coding scheme which in some cases parallels the FIPS codes. The feature network of complete chains is complete for census purposes. For the 1990 census, census enumer-ators identified new and previously unreported street features for the entire Nation during a series of decennial census operations. In some areas, local officials reviewed the census maps and identified new features and feature changes. Similar operations are planned for the 2000 census. The TIGER/ Line ® files contain limited point and area landmark data. The enumerator updates from the 1990 census did not stress landmark features. Computer file matching and automated updates from the Economic and Agriculture censuses added landmarks and key geographic locations (KGLs). As source material from the US Postal Service and local agencies is integrated into the Census TIGER ® data base, the number of landmarks and KGLs is expected to increase. Canada side: None available
Horizontal Positional Accuracy	US side: The Census Bureau’s mission to count and profile the Nation’s people and institutions does not require very high levels of posi-tional accuracy in its geographic products. Its files and maps are designed to show only the relative positions of elements. Coordinates in the TIGER/Line ® files have six implied decimal places. The positional accuracy of these coordinates is not as great as the six decimal places suggest. The positional accuracy varies with the source materials used, but at best meets the established National Map Accuracy standards (approximately + Ú – 167 feet) where 1:100,000- scale maps from the USGS are the source. The Census Bureau can not specify the accuracy of feature updates added by its field staff or of features derived from the GBF/DIME-Files or other map sources. Thus, the level of positional accuracy in the 1995 TIGER/Line ® files is not suitable for high-precision measurement applications such as engineering problems, property transfers, or other uses that might require highly accurate measurements of the earth’s surface. Despite the fact that TIGER/Line ® data positional accuracy is not as high as the coordinate values imply, the six-decimal place precision is useful when producing maps. This precision allows you to place features that are next to each other on the ground in the correct position, relative to each other, on the map without overlap. Canada side: None available
Vertical Positional Accuracy	Not applicaple
Lineage	US side: State hydrology coverages were created for MN, WI, and MI by merging the counties together for each state. The shoreline was then selected for each state (including islands), and 'put' into a coverage. The canadian islands and shoreline were later added using 'put' as well. Further information: Source codes that specify the original digital source of complete chains in the TIGER/Line ® files are listed in the Sources section of this chapter. These codes cover the source categories in the Census TIGER ® data base: initial source, pre-1990 computer operations, office operations, enumer-ator operations, local official updates, post-1990 census updates, and pre-2000 computer operations. The initial sources used to create the Census TIGER ® data base were the USGS 1:100,000-scale Digital Line Graph (DLG), USGS 1:24,000-scale quadrangles, the Census Bureau’s 1980 geographic base files (GBF/DIME-Files), and a variety of miscellaneous maps for selected areas outside the contiguous 48 states. The DLG coverage is extensive, albeit of variable currency, and comprises most of the rural, small city, and suburban area of the TIGER/Line ® files. GBF/DIME-File coverage areas were updated through 1987 with the manual translation of features from the most recent aerial photography available to the Census Bureau. In order to create a current geographic data base for the extraction of the 1995 TIGER/Line ® files, the Census Bureau used various internal and external procedures through 1995 to update and maintain the Census TIGER ® data base. While the Census Bureau has made a reasonable and systematic attempt to gather the most recent information available about the features that this file portrays, the Census Bureau cautions users that the files are no more complete than the source documents used in their compilation, the vintage of those source documents, and the translation of the information on those source documents. The Census Bureau also made other corrections and updates to the map sheets supplied by local participants in various Census Bureau programs. Unconfirmed local updates originated from map reviews by local government officials or their liaisons. Maps were sent to the highest elected official of governmental units between 1990-1995 for use in various census programs, and some maps were returned with update annotations and corrections. The Census Bureau generally added the updates to the Census TIGER ® data base without extensive checks when the elected official approved the boundary or feature cor-rection. Changes made by local officials do not have geodetic control. Canada side: Each 1:250,000 quad was converted to a shapefile using mifshape. The shapefiles were then merged in Arcview. The shoreline and islands were extracted. Both the US and Canadian data were converted from shapefiles to Arc coverages and appended together. To do this, many items were dropped from the US side so that both sides could be brought together. This resulted in a field called 'hydroclass.' Then, a 50 km buffer of the Lake Superior Basin Boundary was used to clip out the relevant area. The data then was split into counties for the US side, and kept whole on the Canada side.
Source Scale Denominator	100000
Section 3	Spatial Data Organization Information - - - - - - Go back to top
Native Data Set Environment	UNIX-ARC/INFO Ver. 7.1.2, Sun Solaris operating system
Geographic Reference for Tabular Data	None
Spatial Object Type	Vector
Vendor Specific Object Types	Arc, line
Tiling Scheme	US side: counties, Canada: canada-wide
Section 4	Spatial Reference Information - - - - - - Go back to top
Horizontal Coordinate Scheme	Geographic (Lat. Long.)
Ellipsoid	GRS80
Horizontal Datum	NAD83
Horizontal Units	Meters
Distance Resolution
Altitude Datum	Not applicable
Depth Datum	Not applicable
Map Projection Name	Albers Equal Area
Map Projection Parameters	Standard Parallel: 29.5 Standard Parallel: 45.5 Longitude Of Central Meridian: -96 Latitude Of Projection Origin: 23 False Easting: 0 False Northing: 0
Other Coordinate System's Definition	Planar Coordinate Encoding Method: Coordinate Pair Abscissa Resolution: 1 Ordinate Resolution: 1 Semi-Major Axis: 6378206.4 Denominator of Flattening Ratio: 294.98
Section 5	Entity and Attribute Information - - - - - - Go back to top
Entity and Attribute Overview	Entity and attribute information is self explanatory. There are the typical attributes such as shape, lenth, etc. The only noteworthy attribute is 'hydroclass' which specifies the types of rivers such as stream or waterway. See lineage.
Entity and Attribute Detailed Citation	None
Section 6	Distribution Information - - - - - - Go back to top
Publisher	Natural Resources Research Institute
Publication Date	Unpublished material
Contact Person Information	Gerald Sjerven, GIS Specialist Natural Resources Research Institute 5013 Miller Trunk Hwy Duluth, Minnesota 55811 Phone: (218)-720-4388 FAX: (218)-720-4328 E-mail: gsjerven@sage.nrri.umn.edu
Distributor's Data Set Identifier
Distribution Liability	No warranty expressed or implied is made regarding the accuracy or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies both to individual use of the data and aggregate use with other data. It is strongly recommended that careful attention be paid to the contents of the metadata file associated with these data. The University of Minnesota shall not be held liable for improper or incorrect use of the data described and/or contained herein.
Transfer Format Name	ARC/Info export format
Transfer Format Version Number
Transfer Size
Ordering Instructions
Online Linkage	Click here to download data. (See Ordering Instructions above for details.) By clicking here, you agree to the notice in "Distribution Liability" above.
Section 7	Metadata Reference Information - - - - - - Go back to top
Metadata Date	08/25/1999
Contact Person Information	Joel Nelson, GIS Intern Natural Resource Research Institute 5013 Miller Trunk Highway Duluth, Minnesota 55811 Phone: (218)-720-4254 FAX: (218)-720-4328 E-mail: jnelson@sage.nrri.umn.edu
Metadata Standard Name	Minnesota Geographic Metadata Guidelines
Metadata Standard Version	Datalogr 2.01
Metadata Standard Online Linkage	http://www.lmic.state.mn.us/gc/stds/metadata.htm

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