King County GIS Center
King Street Center
201 S. Jackson St.
Suite 706
Seattle, WA 98104
giscenter@kingcounty.gov

+ 47.59909 N
- 122.33136 W

+ 47°  35' 56.72"
- 122° 19' 52.90"

 

Five (5) foot-interval index contour isolines

Description | Contacts | Attribute Information | Constraints

Data layer thumbnail image

Description

Layer name: CONTOUR005
Subject category: topo
Title: Five (5) foot-interval index contour isolines
Feature Count: 1225
Feature Type: Line
Abstract: Contour isolines with interval in feet as defined by numerical suffix to data tile. For example t22r04_ctr005 indicates contours for the township 24, range 04 tile with a 5-foot contour interval. Zone and region layers are constructed with a greater contour interval such as _ctr010 representing a 10-foot contour interval. All tiles have identical attribute structures with defined index contours. For file name consistency all township tiles are titled with a 005 suffix. However, due to software-limitations in processing and display restrictions not all tiles contain five-foot contours. For Range 2 through 7, tiles contain five-foot contours, regardless of elevation range. For Range 8 through 14, tiles do not contain five-foot contours for elevation ranges greater than 1000. This means that for tiles where all elevations are greater than 1000 there will be no five foot contours. This 1000-foot demarcation was used to reduce file size and improve drawing performance in elevated, high-relief areas while still providing adequate topographic definition. The 1000-ft breakover point was also chosen as a rough urban/rural dividing line. These contours were derived from the digital ground model grid lattice (DGM) developed initially from the mass point LiDAR file, as detailed in the Process section. As several processing steps were involved, including smoothing and artifact removal, these contours are provided only as an interpretation of the earth's surface and do not meet the definition of topography per chapter 18.43 of the Revised Code of Washington. These contours do not depict the topography relative to any particular property. Any use of this information without additional verification by competent professionals is inappropriate.
Purpose: The contour interval represents a best compromise between the vertical and horizontal accuracy of the source data and the need for a general use cartographic and analysis product. At the contour interval indicated for a given tile the data provide a reasonable depiction of the general shape of the land useful for determining general landform, slope, and elevation. As, by nature, LiDAR data contain some percent of non-ground points, the contours cannot be considered absolute or without error. The index contour attributes allow the data to be reselected or symbolized to display less detail for smaller scale areas.
Status: Complete
Updated: Irregular
Time period of content: (single date,as YYYYMMDD):: 20091201
Time period of content: (date range, as YYYYMMDD):: -
Spatial reference: WA State Plane North
FGDC Documentation: Classic or FAQ
Open Data Availability: Yes
Place Keywords: Washington state, Pacific NW, King County, WA, Seattle,
Theme Keywords: bathymetry, topo, Digital Ground Model (DGM), Contours, LiDAR digital elevation data, Elevation data, Bare-Earth, Virtually Deforested, elevation,
Lineage: Available
Supplemental Information: The contours were generated to the extent of the individual tiles of the idxptrbmr index (index polygons for township-range, minimum bounding rectangle).Effort was made to minimize any edge effects at the edge of a tile but the tiles have not been edge-matched to adjacent tiles. A supplemental set of tiles were created in early 2005. This set is found in the idxptrmbr folder called dgm_ctrneat. It consists of the same contour information in the original dgm_contour folder, but the tiles are edgematched and clipped to the extent of the PLSS twnshp grid. Although these files are derived from the dgm_contour set they are not necessarily produced at the same time that updates to the dgm_contour set are made.

Contacts

Maintained by:
King County GIS Center
Primary: Victor High, Senior GIS Specialist, 206-477-4408
(How to e-mail a County contact)
Secondary: KCGIS Center; giscenter@kingcounty.gov. This mailbox is monitored during business hours.

Attribute Information

ItemDescriptionDomain
_TILE_ID_Tile identifierInteger value defining township and range of tile; i.e., T22R04 would be 2204
_ELEVATION_Elevation of contour isoline in feet
_IDX_MINOR_Indexes each elevation value as to either a 5-foot multiple only,or a 5 and 10-foot multiple. For example, the 105 foot isoline would be indexed as a 5, while a 110 foot isoline would be indexed as a 10.
10
_IDX_20FT_Indexes each elevation value as to whether it is a multiple of 20, cumulative multiple of 100, 500 or 100, or none of these. Useful for showing 100 foot boss contours with aggregate 20's.
1
_IDX_40FT_Indexes each elevation value as to whether it is a multiple of 40, cumulative multiple of 200 or 1000, or not either. Useful for showing every 200 foot boss contour with aggregate 40's, comparable to many USGS topographic maps.
1
_IDX_50FT_Indexes each elevation value as to whether it is a multiple of 50, cumulative multiples of 100, 500 or 1000 (feet), or none of these. Useful for showing generalized contours at 50 foot intervals.
1
50
_IDX_100FT_Indexes each elevation value as to whether it is a multiple of 100, a cumulative multiple of 500 or 1000 (feet), or none of these. Useful for showing generalized contours at 100 foot intervals.
1
_FIPS_CODE_


Constraints

Access: A cooperative data sharing arrangement between the Puget Sound LiDAR Consortium and King County is allows certain formats of the LiDAR data to be distributed with out license or restriction. Certain processing and data handling charges for necessary cost recovery may apply. Access to raw mass point files is by special request and request evaluation only.

Use: King County data are made available with the understanding that they shall be used exclusively by the obtainer or his/her authorized agents. Digital products may not be reproduced or redistributed in any form or by any means without the express written authorization of King County. These contours are based upon LiDAR returns which inherently contain some "non ground-surface" values. In addition, the contours were smoothed, as outlined in the Process Section, to create a more traditional cartographic product. As such, these contours represent only the general shape of the land and do not meet the definition of topography per chapter 18.43 of the Revised Code of Washington. These contours do not depict the topography relative to any particular property. Any use of this information without additional verification by competent professionals is inappropriate.