GIS Data Catalog

Elevation Contour Lines for King County - 40 Foot Index Contours

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Summary


40 foot interval elevation contour lines for King County, derived primarily from 2021 lidar.

Description


Forty (40) foot interval elevation contours for King County, derived primarily from 2021 lidar.

The 40 foot contours are a subset of the 5 foot contour layer.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.

The data provide a reasonable depiction of the general shape of the land, useful for determining general landform, slope, and elevation.

These contours are provided only as an interpretation of the earth's surface for reference use and do not replace the need for a professional land survey.


Layer information

Layer Name contour040_line
Subject Category Topography
Title Elevation Contour Lines for King County - 40 Foot Index Contours
Feature Count 63681
Feature Type Line
Next Update Irregular
Spatial reference EPSG:2926
Control ID 89
Place Keywords Washington State, Pacific NW, King County, Seattle
Theme Keywords Contours, Elevation Data, Digital Elevation Model, Elevation
Supplemental Information None

Table Preview


Attribute information

OBJECTID

From ESRI

Description

Internal feature number.

Domain

2659999

ELEVATION

From KCGISC

Description

Elevation of contour isoline in feet

Domain

Not Found

SHAPE

From ESRI

Description

Feature geometry.

Domain

Coordinates defining the features.

Shape.STLength()

From SQL Server

Description

Returns the total length of the elements in a geometry instance.

Domain

Double


Contact information

Maintained by KCGIS Center
Primary KCGIS Center

giscenter@kingcounty.gov


Terms of Use

Summary


40 foot interval elevation contour lines for King County, derived primarily from 2021 lidar.

Description


Forty (40) foot interval elevation contours for King County, derived primarily from 2021 lidar.

The 40 foot contours are a subset of the 5 foot contour layer.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.

The data provide a reasonable depiction of the general shape of the land, useful for determining general landform, slope, and elevation.

These contours are provided only as an interpretation of the earth's surface for reference use and do not replace the need for a professional land survey.


Contact information

Maintained by KCGIS Center
Primary KCGIS Center

giscenter@kingcounty.gov


Terms of use and copyright


Change history

12/1/2021

County-wide lidar update for 2021.

7/29/2019

Lidar update 2019 from Cedar, Green, Snoqualmie, & South Vashon pts.

9/15/2017

Townships updated: t19r07, t20r04, t20r05, t20r06, t20r07, t21r02, t21r03, t21r04, t21r05, t21r06, t21r07, t21r08, t21r09, t21r10, t21r11, t22r02, t22r03, t22r04, t22r05, t22r06, t22r07, t22r08, t22r09, t22r10, t22r11, t23r02, t23r03, t23r04, t23r05, t23r06, t23r07, t23r08, t23r09, t24r03, t24r04, t24r05, t24r06, t24r07, t24r08, t25r03, t25r04, t25r05, t25r06, t25r07, t25r08, t25r09, t25r10, t26r03, t26r04, t26r05, t26r06, t26r07, t26r08, t26r09, t26r10, t27r03, t27r04, t27r05, t27r06, t27r07

10/25/2016

Contours are derived from the latest DGM mosaic model.

A 5 foot county wide contour layer is maintained in SDE Township DGM are extracted from the mosaic, contoured at 5 feet, the old township selected and deleted, and the new contour township appended back.

Separate township layers are produced for posting to shapefiles and ftp portal.

5 Index contour layers for the county are also produced by selection from the master county wide 5 foot contour layer.

10, 20, 40, 50 and 100 foot contour indexes for the county are produced.

11/28/2008

Tiles are clipped from contour005 using the 7500 index squares.

Contours are then converted into Autocad version 2004 DXF format.

11/26/2006

Produce tile list of DXF contours needed by intersecting p_lidar_all extent layer with index layer idxp7500.

Write python script \images\ElevMaint\ctr27500\clip_dxf3.py to: Check for existence of DXF file If no file, then Select each tile.

Build a clip.

Clip SDE layer GISPROD plib.sde.plibrary.TOPO.contour005_line.

ExportCAD_conversion using DXF_R2004 option.

Update 7

Townships updated: t21r04, t21r05, t23r07, t24r07,

Update 8

2016 Quantum Spatial lidar update for western part of county.

Township contours updated: t19r08, t19r09, t19r10, t20r07, t20r08, t20r09, t20r10, t21r07, t21r08, t22r07, t22r08, t22r09, t22r10, t22r11, t23r07, t23r08, t23r09, t23r10, t23r11, t24r07, t24r08.

Update 9

Contours built from dgm township GRIDs, neat clipped, then appended together without edge matching.

Update 10

Data from 2004 3di West for Snoqualmie, Green River Study was integrated into master elevation database.

This new elevation control was assembled from stereo pair orthoimagery, and approximates 2-foot contour accuracy necessary for FEMA flood plain mapping.

The TIN surface created for the project was converted to a point dataset and then incorporated into the elevation database similar to the original lidar data.

Data from 2007 Ground LiDAR ascii data from Watershed Science for parts of White River are integrated into master elevation database.

This is the first update that was converted from Arc\Info GRID\AML to ARCGIS SDE RASTER\Python.

See documentation: DGM  Update Procedure.doc The following townships were updated: T19R06 T19R07 T21R04 T21R05 T21R06 T22R04 T22R05 T23R04 T23R05 T24R04 T24R07 T25R06 T25R07 T26R06 T26R07 T27R06.