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This page last updated: 04/03/2002
Metadata created using Minnesota Geographic Metadata Guidelines
| Originator | Metropolitan Council | |||
| Abstract | This grid dataset was developed by calculating the maximum rate of change between elevation points that are 30 meters apart in a 30 meter digital elevation model grid. This dataset shows three classes of sloped areas. Class1 includes slopes from 0 to 12 percent, class 2 includes slopes from 12 to 18 percent, and class 3 includes slopes greater than 18 percent. However, there is no guarantee that such slopes exist within any given slope class in this grid file. This grid is not suitable for determining the precise location or actual size of areas that are undevelopable due to slopes, but merely the general location of areas where development might be constrained due to steep slopes. Based on visual inspection when laying the dataset over 2000 orthophotos, the steep slope classes appear to be a reasonable representation of areas of steep slope, although these results have not been field checked. |
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| Browse Graphic | View a sample of the data. | |||
| Time Period of Content Date | 1980 | |||
| Currentness Reference | Base information is as current as the publication of its source USGS quadrangle maps which vary in publication date from 1979 to 1990. | |||
| Access Constraints | None | |||
| Use Constraints | None | |||
| Distributor Organization | Metropolitan Council | |||
| Ordering Instructions | This dataset is distributed on the internet by clicking below after 'Online Linkage'. Doing so will tell your browser to download a 'ZIP' file which will contain the following: - Grid dataset - metdata for the dataset (.htm) - NOTICE.RTF, an important notice about this dataset that can be read by any word processing software. |
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| Distribution Liability | NOTICE: The Geographic Information System (GIS) Data to which this notice is attached are made available pursuant to the Minnesota Government Data Practices Act (Minnesota Statutes Chapter 13). THE GIS DATA ARE PROVIDED TO YOU AS IS AND WITHOUT ANY WARRANTY AS TO THEIR PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR ANY PARTICULAR PURPOSE. The GIS Data were developed by the Metropolitan Council for its own internal business purposes. The Metropolitan Council does not represent or warrant that the GIS Data or the data documentation are error-free, complete, current, or accurate. You are responsible for any consequences resulting from your use of the GIS Data or your reliance on the GIS Data. You should consult the data documentation for this particular GIS Data to determine the limitations of the GIS Data and the precision with which the GIS Data may depict distance, direction, location, or other geographic features. If you transmit or provide the GIS Data (or any portion of it) to another user, it is recommended that the GIS Data include a copy of this disclaimer and this metadata. | |||
| Online Linkage | I AGREE to the notice in "Distribution Liability" above. Clicking to agree will begin the download process (See Ordering Instructions above for details.) | |||
Go to Section:
1. Identification Information
2. Data Quality Information
3. Spatial Data Organization Information
4. Spatial Reference Information
5. Entity and Attribute Information
6. Distribution Information
7. Metadata Reference Information
| Section 1 | Identification Information | Top of page | ||
| Originator | Metropolitan Council | |||
| Title | Steep Slope Class Grid | |||
| Abstract | This grid dataset was developed by calculating the maximum rate of change between elevation points that are 30 meters apart in a 30 meter digital elevation model grid. This dataset shows three classes of sloped areas. Class1 includes slopes from 0 to 12 percent, class 2 includes slopes from 12 to 18 percent, and class 3 includes slopes greater than 18 percent. However, there is no guarantee that such slopes exist within any given slope class in this grid file. This grid is not suitable for determining the precise location or actual size of areas that are undevelopable due to slopes, but merely the general location of areas where development might be constrained due to steep slopes. Based on visual inspection when laying the dataset over 2000 orthophotos, the steep slope classes appear to be a reasonable representation of areas of steep slope, although these results have not been field checked. |
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| Purpose | This dataset shows three classes of sloped areas. Class1 includes slopes from 0 to 12 percent, class 2 includes slopes from 12 to 18 percent, and class 3 includes slopes greater than 18 percent. However, there is no guarantee that such slopes exist within any given slope class in this grid file. This grid is not suitable for determining the precise location or actual size of areas that are undevelopable due to slopes, but merely the general location of areas where development might be constrained due to steep slopes. |
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| Time Period of Content Date | 1980 | |||
| Currentness Reference | Base information is as current as the publication of its source USGS quadrangle maps which vary in publication date from 1979 to 1990. | |||
| Progress | Complete | |||
| Maintenance and Update Frequency | None planned | |||
| Spatial Extent of Data | Twin Cities 7 County Metropolitan Area. This includes the counties of Anoka, Carver, Dakota, Hennepin, Ramsey, Scott and Washington in Minnesota. | |||
| Bounding Coordinates | -94.012 -92.732 45.415 44.471 |
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| Place Keywords | Twin Cities, Anoka County, Carver County, Dakota County, Hennepin County, Ramsey County, Scott County, Washington County | |||
| Theme Keywords | Steep Slopes, Slopes, Digital Elevation Models, DEM, Topography, elevation | |||
| Theme Keyword Thesaurus | None | |||
| Access Constraints | None | |||
| Use Constraints | None | |||
| Contact Person Information | Steve Kloiber,
Senior Water Resources Planner Metropolitan Council 390 Robert Street North St. Paul, Minnesota 55101-1805 Phone: 651-602-1056 FAX: 651-602-1130 E-mail: steve.kloiber@metc.state.mn.us | |||
| Browse Graphic | View a sample of the data. | |||
| Browse Graphic File Description | Sample map showing the SteepSlopeClassGrid layer. | |||
| Associated Data Sets | 30 meter DEM |
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| Section 2 | Data Quality Information | Top of full metadata | Top of page | |
| Attribute Accuracy | This dataset shows three classes of sloped areas. Class1 includes slopes from 0 to 12 percent, class 2 includes slopes from 12 to 18 percent, and class 3 includes slopes greater than 18 percent. However, there is no guarantee that such slopes exist within any given slope class in this grid file. | |||
| Logical Consistency | The dataset is topologically correct and verified. | |||
| Completeness | Entire seven county geographic area is covered. | |||
| Horizontal Positional Accuracy | The DEM upon which this data is based was derived from contours from USGS 1:24,000 scale maps. Thus, the horizontal positional accuracy can probably be reasonably estimated based on the characteristics of source materials and processing techniques to be no better than +/- 45-60 feet (14 - 18 meters). | |||
| Vertical Positional Accuracy | Vertical position is not an attribute of the steep slope grid data; however, these data are based upon elevation data from the 30-meter DEM. The source data is derived from 7.5 minute quads, and therefore the vertical accuracy of the source data cannot be assumed to exceed National Map Accuracy Standards for 1:24,000 scale maps with 10-foot elevation contours (+/- 5 feet). | |||
| Lineage | The process used to derive the steep slope grid from the 30-meter DEM is briefly described below. Step 1. Convert the elevation intervals of the 30 meter DEM from feet to meters. Step 2. Computed slope from original 30 meter DEM based on 30 meter cells using ArcView Spatial Analyst's 'Derive Slope' function. Step 3. Convert slope grid from degrees to percent as follows Percent Slope (Rise/Run) = tangent(slope_degrees/57.29578) using ArcView Spatial Analyst's 'Map Calculator' function. Step 4: Used Spatial Analyst's 'Reclassification' function to reclassify the floating point values into three integer categories. Class 1 is slopes from 0 to 12 percent, class 2 is slopes from 12 to 18 percent, and class 3 is slopes greater than 18 percent. LINEAGE FOR SOURCE 30 METER DEM DATA: The software used to derive the dataset was ANUDEM ( http://cres.anu.edu.au/outputs/software.html) Input data included elevation contours derived from USGS 10-foot DLG contours, topographic depression points, and lake polygons extracted from the National Wetlands Inventory by the Minnesota DNR. Tile boundaries for the lake data were dissolved prior to processing. Lake surface elevations were calculated as zonal minimums of surface elevations for each lake. The resulting output is in a floating point grid, with units of feet. The interpolation parameters used in ANUDEM for this process were as follows: Drainage Enforcement On Elevation Data Consists Mainly of Contours Non-Negative RMS Factor = 1.0 Vertical SE = 0.0 Roughness Penalty = 0.0 (Recommended for Contour Data) Elevation Tolerance 1 = 5.0 feet Elevation Tolerance 2 = 100.0 feet Maximum Number of Iterations = 40 Elevation Units = Feet Elevation Minimum = 660.0 feet Elevation Maximum = 1230.0 feet Elevation Centered on Grid Cell Center Horizontal Position Units = Meters Grid Spacing = 30.0 X Limit (Minimum) = 410730.0 X Limit (Maximum) = 529740.0 Y Limit (Minimum) = 4913520.0 Y Limit (Maximum) = 5038710.0 Number of Columns in Output Grid = 3967 Number of Rows in Output Grid = 4173 Grid Margin = 20 cells Number of Input Files = 5 Input File 1 = input_pt.gen (ArcInfo Point Data) Input File 2 = hyps_upl.gen (ArcInfo Contour Data) Input File 3 = dem_lake.gen (ArcInfo Lake Boundary Data) Input File 4 = dem_sink.gen (ArcInfo Sink Point Data) Input File 5 = union1.gen (ArcInfo Polygon) NOTE: Drainage enforcement was used, but stream data was not used. The data have not been hydrologically corrected. Using the drainage enforcement option has the effect of filling small spurious sinks that are created as an artifact of the interpolation process. Only sinks that exceed the Elevation Tolerance 1 value (5.0 feet) or sinks that are specifically identified in the topographic depression data file will be retained. |
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| Source Scale Denominator | 24000 | |||
| Section 3 | Spatial Data Organization Information | Top of full metadata | Top of page | |
| Native Data Set Environment | ArcInfo Version 8x Grid | |||
| Geographic Reference for Tabular Data | None | |||
| Spatial Object Type | Raster | |||
| Vendor Specific Object Types | Integer grid, 30 meter cell size | |||
| Tiling Scheme | One layer for entire area. | |||
| Section 4 | Spatial Reference Information | Top of full metadata | Top of page | |
| Horizontal Coordinate Scheme | UTM | |||
| Ellipsoid | GRS80 | |||
| Horizontal Datum | NAD83 | |||
| Horizontal Units | Meters | |||
| Distance Resolution | 30 | |||
| Cell Width | 30 | |||
| Cell Height | 30 | |||
| UTM Zone Number | 15 | |||
| Section 5 | Entity and Attribute Information | Top of full metadata | Top of page | |
| Entity and Attribute Overview | Grid Class = 1, 2, or 3 |
| Entity and Attribute Detailed Citation | None | |||
| Section 6 | Distribution Information | Top of full metadata | Top of page | |
| Publisher | Metropolitan Council | |||
| Publication Date | Unpublished material | |||
| Contact Person Information | Mark Kotz GIS Database Administrator Metropolitan Council 390 Robert Street North St. Paul, Minnesota 55101-1805 Phone: 651.602.1644 FAX: 651.602.1674 E-mail: mark.kotz@metc.state.mn.us |
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| Distributor's Data Set Identifier | SteepSlopeClassGrid | |||
| Transfer Format Name | zipped grid dataset | |||
| Transfer Format Version Number | ArcInfo 8x | |||
| Transfer Size | 1 MB for zip file. | |||
| Ordering Instructions | This dataset is distributed on the internet by clicking below after 'Online Linkage'. Doing so will tell your browser to download a 'ZIP' file which will contain the following: - Grid dataset - metdata for the dataset (.htm) - NOTICE.RTF, an important notice about this dataset that can be read by any word processing software. |
|||
| Distribution Liability | NOTICE: The Geographic Information System (GIS) Data to which this notice is attached are made available pursuant to the Minnesota Government Data Practices Act (Minnesota Statutes Chapter 13). THE GIS DATA ARE PROVIDED TO YOU AS IS AND WITHOUT ANY WARRANTY AS TO THEIR PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR ANY PARTICULAR PURPOSE. The GIS Data were developed by the Metropolitan Council for its own internal business purposes. The Metropolitan Council does not represent or warrant that the GIS Data or the data documentation are error-free, complete, current, or accurate. You are responsible for any consequences resulting from your use of the GIS Data or your reliance on the GIS Data. You should consult the data documentation for this particular GIS Data to determine the limitations of the GIS Data and the precision with which the GIS Data may depict distance, direction, location, or other geographic features. If you transmit or provide the GIS Data (or any portion of it) to another user, it is recommended that the GIS Data include a copy of this disclaimer and this metadata. | |||
| Online Linkage | I AGREE to the notice in "Distribution Liability" above. Clicking to agree will begin the download process (See Ordering Instructions above for details.) | |||
| Section 7 | Metadata Reference Information | Top of full metadata | Top of page | |
| Metadata Date | 04/03/2002 | |||
| Contact Person Information | Steve Kloiber,
Senior Water Resources Planner Metropolitan Council 390 Robert Street North St. Paul, Minnesota 55101-1805 Phone: 651-602-1056 FAX: 651-602-1130 E-mail: steve.kloiber@metc.state.mn.us |
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| Metadata Standard Name | Minnesota Geographic Metadata Guidelines | |||
| Metadata Standard Version | 1.2 | |||
| Metadata Standard Online Linkage | http://www.gis.state.mn.us/stds/metadata.htm | |||
This page last updated: 04/03/2002
