Steep Slope Areas of Loudoun County, VA | |
Data format: SDE Feature Class File or table name: GISDBB.GISBROW.STEEP_SLOPE_POLY Coordinate system: Lambert Conformal Conic Theme keywords: environment, geoscientificInformation, planningCadastre, steep slope, topography, NRCS, slope classification |
|
Abstract:
The Steep Slope layer identifies areas with a slope greater than 15% in Loudoun County. |
Metadata elements shown with blue text are defined in the Federal Geographic Data Committee's (FGDC) Content Standard for Digital Geospatial Metadata (CSDGM). Elements shown with green text are defined in the ESRI Profile of the CSDGM. Elements shown with a green asterisk (*) will be automatically updated by ArcCatalog. ArcCatalog adds hints indicating which FGDC elements are mandatory; these are shown with gray text.
The Steep Slope layer identifies areas with a slope greater than 15% in Loudoun County.
Steep Slope assists in identifying steep slope areas. Improper uses and disturbances in steep slope areas cause erosion, result in structural failure of structures and roads, and lead to downstream flooding and other hazards.
Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN (vertical datum, if applicable, NAVD88 HARN), US Survey foot units.
ground condition
The steep slopes were derived through a modeling process based on topography. Currently no national standard for this type of process exists. The steep slopes were generated using the best available data for Loudoun County and should only be used as a reference. Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user. These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.
1 Harrison Street SE, 2nd floor
MS 60
Topologically clean
Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data.
Zoning Ordinance requiring steep slopes to be derived from topography.
The Steep Slope layer is developed from Loudoun County's topography feature class. A Digital Elevation Model (DEM) with a 10' cell size grid was derived from topography. The DEM was converted to a slope layer, which contained a slope value within each cell. Slope values were then rounded up to the next integer value. The slope raster was then broken into two categories, 15-25% and 25%+. The steep slope areas less then 5000 sq ft that were not within 25 feet of steep slope areas greater then 5000 sqft. were eliminated unless the combined areas of steep slope polygons within 25 feet of each other totaled 5000 sq ft or greater.
This feature class was loaded into the Loudoun County corporate ARCSDE Geodatabase as a polygon feature class.
Internal feature number.
ESRI
Slope category of steep slope area
Loudoun County
15-25% slope
25% and greater
Temporary attribute field. To work with Loudoun County Land Managment Information System (LMIS)
Loudoun County
Source that created or modified feature class
Loudoun County
Date feature class created or modified
Loudoun County
Not for public distribution. Internal User ID of editor creating or modifying feature class.
Loudoun County
Feature geometry.
ESRI
SDE area of steep slope area
Loudoun County
SDE perimeter of steep slope area
Loudoun County
ST_UPD_SOURCE: Source that created or modified feature class
Source Definition 0 Undetermined 10 Legacy 20 County 30 Contract 40 Model
1 Harrison Street S.E., 2nd floor
MS 65
Every reasonable effort has been made to assure the accuracy of these data. Loudoun County, Virginia does not assume any liability arising from the use of these data. These data are provided without warranty of any kind, expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular service. Reliance on these data is at the risk of the user.
ESRI Personal Geodatabase Feature Class
ESRI Shapefile
AutoCad Digital Exchange File
Size limit: 4.5 GB. Visit our website at: http://www.loudoun.gov/omagi, click on "Loudoun County Mapping Documents & Order Forms." The "Forms" directory will lead you to custom & standard (countywide) data order forms. Hardcopy maps may also be available; please contact the Mapping Office Public Information Counter for more information regarding all data requests.
1 Harrison Street SE, 2nd Floor
MS 65