One-Hundred and Five-Hundred Year Floodzones for Unincorporated Areas in Illinois

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Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: Illinois State Water Survey
Publication_Date: 1996
Title:
One-Hundred and Five-Hundred Year Floodzones for Unincorporated Areas in Illinois
Edition: 20060817
Geospatial_Data_Presentation_Form: vector digital data
Series_Information:
Series_Name: ISGS GIS Database
Issue_Identification: GISDB_HYDRO.IL_Flood_Zones_1986_Py
Online_Linkage: <http://www.isgs.illinois.edu/>
Online_Linkage: <http://illinois.edu>
Description:
Abstract:
This feature class was quickly assembled from old Arc/Info coverages to produce a general graphic image and has not reviewed or quality-controlled in any way and is not supported.

This is a statewide polygon feature class of 100 year and 500 year flood zones as of 1986 for the unincorporated areas of Illinois as indicated on Federal Emergency Management Agency (FEMA) National Flood Insurance Program (FIRM) maps and Flood Hazard Boundary maps.

The statewide data layer was created by appending data from 102 county-wide Arc/Info coverages originally released on Illinois DNR GIS data CDs dated 1996.

The data were digitized from paper maps. RMS values were not more than twenty feet in the original digitizing process. Mapscale: 1:6000 to 1:24,000.

Purpose:
These data are appropriate for use in local and regional thematic analysis. The data are not appropriate as a geodetic, legal or engineering base. The data set was not and is not intended as a substitute for surveyed locations, such as can be determined by a registered Public Land Surveyor. Although useful in a GIS as a reference base layer for maps, the data set has no legal basis in the definition of boundaries, property lines, or flood zones.
Supplemental_Information:
This statewide edition of the data is designated 20060817. The previous edition, stored as county-by-county coverages on the ISGS GIS system, was designated edition 1.0.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 1986
Currentness_Reference: As indicated on FEMA and FIRM maps
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -91.513518
East_Bounding_Coordinate: -87.495214
North_Bounding_Coordinate: 42.508002
South_Bounding_Coordinate: 36.987594
Keywords:
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: floodzones
Theme_Keyword: floodplain
Place:
Place_Keyword_Thesaurus: none
Place_Keyword: Illinois
Access_Constraints:
Access to this instance of the data is limited to INRS staff.

Any access to these data, Web sites, computer systems, electronic services, and electronic networks is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign and the University of Illinois Web Privacy Notice.

Links to these are provided in the Cross References section.

Use_Constraints:
These data are not to be distributed outside of the ISGS.

Any use of these data is governed by University and campus policies, in particular, but not limited to, the Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign and the University of Illinois Web Privacy Notice. Links to these are provided in the Cross References section.

Map information is to be used at a scientifically and cartographically appropriate scale, that is, at a scale no greater than indicated on the map or as described in the documentation of the map or map data.  Map information is not appropriate for, and is not to be used as, a geodetic, legal, or engineering base. Map information has no legal basis in the definition of boundaries or property lines and is not intended as a substitute for surveyed locations such as can be determined by a registered Public Land Surveyor.

The data do not replace the need for detailed site-specific studies.

Point_of_Contact:
Contact_Information:
Contact_Instructions: Please refer to the Distribution Information section.
Data_Set_Credit: GIS Processing: ISWS and ISGS staff
Native_Data_Set_Environment: ArcSDE 9.1 on Oracle 10g
Cross_Reference:
Citation_Information:
Title: University of Illinois Web Privacy Notice
Online_Linkage: <http://www.vpaa.uillinois.edu/policies/web_privacy.cfm>
Cross_Reference:
Citation_Information:
Title:
University Copyright Policy (stated in the General Rules Concerning University Organization and Procedure, Article III, Section 4)
Online_Linkage: <http://www.uillinois.edu/trustees/rules.cfm#sec34>
Cross_Reference:
Citation_Information:
Title:
Policy on Appropriate Use of Computers and Network Systems at the University of Illinois at Urbana-Champaign
Online_Linkage: <http://www.fs.uiuc.edu/cam/CAM/viii/viii-1.1.html>

Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: No report.
Logical_Consistency_Report: No report.
Completeness_Report:
Data are not included for incorporated areas of the state. Data for other areas may also be absent. There has been no quality-control or error checking performed on these data subsequent to compiling the county-by-county coverages into a statewide feature class.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report: No report.
Lineage:
Process_Step:
Process_Description:
The 100 year and 500 year floodzones for the unincorporated areas as indicated on the Federal Emergency Management Agency (FEMA) National Flood Insurance Program (FIRM) maps and Flood Hazard Boundary maps were digitized from paper maps. When digitizing, all RMS values were not more than twenty feet.
Process_Date: Unknown
Process_Step:
Process_Description:
The 102 county-by-county coverages were compiled into a single statewide coverage. The coverage data were in the customary ISGS Lambert Conformal Conic projection. For the 98 county coverages with identical PAT items and definitions, this was accomplished with the Arc Workstation command APPEND, as follows:

APPEND FLOODZONES POLY <list of 98 coverages> END

The coverage was then cleaned, dissolved, and converted to a shapefile:

CLEAN FLOODZONES FLOODZONES2 0.002 0.002 POLY DISSOLVE FLOODZONES2 FLOODZONES3 COLOR POLY (the item COLOR contained the floodzone designations) ARCSHAPE FLOODZONES2 POLY floodzones.shp

The shapefile was imported into a personal geodatabase as a standalone feature class. The polygon data for the remaining four counties (Clark, Franklin, Kankakee, and Lawrence, which had irregular PAT items and definitions) were imported into the feature class using the Load function of ArcCatalog.

The data were then reprojected to lon/lat NAD83 using the Project function of ArcToolbox:

Executing (Project_1): Project C:\floodzones.mdb\floodzone_py C:\floodzones.mdb\floodzone_py_Project GEOGCS['GCS_North_American_1983',DATUM['D_North_American_1983',SPHEROID['GRS_1980',6378137.0,298.257222101]],PRIMEM['Greenwich',0.0],UNIT['Degree',0.0174532925199433]] NAD_1927_To_NAD_1983_NADCON Start Time: Thu Aug 17 09:48:45 2006 Executed (Project_1) successfully. End Time: Thu Aug 17 10:11:07 2006 (Elapsed Time: 22 minutes 22 seconds)

The values in field FLOODZONE were changed. Originally 72 indicated 100-year flood zone and 70 indicated 500-year floodzone. These were changed to 100 and 500 respectively.

Process_Date: 20060816

Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 8438

Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Geographic:
Latitude_Resolution: 0.000001
Longitude_Resolution: 0.000001
Geographic_Coordinate_Units: Decimal degrees
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
Vertical_Coordinate_System_Definition:
Altitude_System_Definition:

Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: GISDB_HYDRO.IL_Flood_Zones_1986_Py
Attribute:
Attribute_Label: SHAPE
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: ESRI
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: floodzone
Attribute_Definition: Designation of flood zone type
Attribute_Definition_Source: Metadata of source coverages
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 0
Enumerated_Domain_Value_Definition: not a flood zone
Enumerated_Domain:
Enumerated_Domain_Value: 100
Enumerated_Domain_Value_Definition: 100-year flood zone
Enumerated_Domain:
Enumerated_Domain_Value: 500
Enumerated_Domain_Value_Definition: 500-year flood zone
Attribute:
Attribute_Label: FLOODZONE
Attribute:
Attribute_Label: OBJECTID
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.AREA
Attribute:
Attribute_Label: SHAPE.LEN
Overview_Description:
Entity_and_Attribute_Detail_Citation: none

Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization:
Information Office, Illinois State Geological Survey (ISGS), a division of the Institute of Natural Resource Sustainability (INRS) of the University of Illinois
Contact_Address:
Address_Type: mailing and physical address
Address: 615 East Peabody Drive
City: Champaign
State_or_Province: Illinois
Postal_Code: 61820
Country: USA
Contact_Voice_Telephone: 217-333-4747
Contact_TDD/TTY_Telephone: 217-785-0211
Contact_Electronic_Mail_Address: isgs@isgs.illinois.edu
Hours_of_Service: 8:00 a.m. - 4:30 p.m., Monday-Friday, U.S. Central Time
Distribution_Liability:
Refer to the Legal Notices of Terms and Conditions of the University of Illinois Web Privacy Policy (there is a link in the Cross References section) for policy statements regarding the following:

Disclaimer of Liability Disclaimer of Warranties and Accuracy of Data Disclaimer of Endorsement Disclaimer for External Links Disclaimer of Duty to Continue Provision of Data Security Choice of Law

By obtaining these data you agree to the provisions of the University of Illinois Web Privacy Policy, regardless of the manner in which the information was obtained.

Technical_Prerequisites:
The data are intended for use with GIS software. The ISGS uses ESRI ArcGIS software, however, ESRI formats can be imported into many different GIS software packages. It is expected that customers who obtain these data have the technical expertise to use GIS software. The ISGS does not provide software support of any kind.

Metadata_Reference_Information:
Metadata_Date: 20090224
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Instructions: Please refer to the Distribution Information section.
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Access_Constraints:
The access constraints as stated for the data apply also to the metadata. Refer to the Access Constraints section of the Identification Information section.
Metadata_Use_Constraints:
The use constraints as stated for the data apply also to the metadata. Refer to the Use Constraints section of the Identification Information section.
Metadata_Extensions:
Online_Linkage: <http://www.esri.com/metadata/esriprof80.html>
Profile_Name: ESRI Metadata Profile

Lineage:

Illinois Natural Resources Geospatial Data Clearinghouse

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