GIS Data Catalog
30-meter Mosaicked DEM, Greyscale hillshade, and elevation-shaded (colorized) hillshade for entire state of Washington
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Summary
DEM and greyscale hillshade are available as 30-meter grid data for subsequent raster processing and analysis for areas outside of extent of higher resolution Lidar and 10-meter USGS data.
Colorized (elevation-shaded) hillshade is resampled at 900 feet, providing a coarser but manageable file for cartographic backdrop.
Description
Single 30-meter mosaick for Digital Elevation data for Washington State.
Standard derived grey-scale hillshade and elevation-shaded hillshade using green to brown shading.
Layer information
| Layer Name | SURFACE_WashingtonStateUSGSDEMHillshade |
| Subject Category | Imagery |
| Title | 30-meter Mosaicked DEM, Greyscale hillshade, and elevation-shaded (colorized) hillshade for entire state of Washington |
| Feature Count | 1 |
| Feature Type | Raster |
| Next Update | As needed |
| Spatial reference | None |
| Control ID | None |
| Place Keywords | Pacific NW, Washington State |
| Theme Keywords | Elevation, Colorized Hillshade, Elevation Model, Hillshade, Topography |
| Supplemental Information |
All these datasets exist only at KeyRegion index level. |
Attribute information
|
OBJECTID
From ESRI |
Description
Internal feature number. DomainSequential unique whole numbers that are automatically generated. |
|
Shape
From ESRI |
Description
Feature geometry. DomainCoordinates defining the features. |
|
Shape_Length
From Esri |
Description
Length of feature in internal units. DomainPositive real numbers that are automatically generated. |
|
Shape_Area
From Esri |
Description
Area of feature in internal units squared. DomainPositive real numbers that are automatically generated. |
|
MosaicID
No Source Noted |
Description
Not Found DomainNot Found |
Contact information
| Maintained by | KCGIS Center |
| Primary |
KCGIS Center
giscenter@kingcounty.gov |
Terms of Use
| License | Terms of use and copyright |
Summary
DEM and greyscale hillshade are available as 30-meter grid data for subsequent raster processing and analysis for areas outside of extent of higher resolution Lidar and 10-meter USGS data.
Colorized (elevation-shaded) hillshade is resampled at 900 feet, providing a coarser but manageable file for cartographic backdrop.
Description
Single 30-meter mosaick for Digital Elevation data for Washington State.
Standard derived grey-scale hillshade and elevation-shaded hillshade using green to brown shading.
Contact information
| Maintained by | KCGIS Center |
| Primary |
KCGIS Center
giscenter@kingcounty.gov |
Terms of use and copyright
| License | Terms of use and copyright |
Change history
| 5/1/2005 |
Western washington mosaick was first converted from BIL format to ESRI Grid format. Then reprojected to King County Standard projection of WA State Plane N, Zone 5601, HPGN, Units Feet. The Z-value was not consistent with the original UTM units of feet. Comparison to more detailed Lidar data for King County area indicated that the DEM elevation values were 2.75x greater than the Lidar values. The Grid values were recalculated to the Lidar base by dividing the z-value by 2.75. Eastern washington mosaick was imported as a ESRI Grid. Reprojected from UTM Zone 11 to KC projection. Z-value in meters was converted to feet by multiplying z-value by 3.2808. The two state halves were merged using the GRID merge command in order of (eastdem,westdem). The merged DEM was processed using Setnull (washdem == 0, washdem) to convert the 0 values to Null. This was done so that the 0 values would not appear in the hillshade image. The DEM was hillshaded using the default arguments and converted to an image using the gridimage command. The colorized version of the hillshade was created using ArcGIS with 50% transparency for hillshade overlain on DEM. The colorramp was imported from a layer file (/plibrary3/keyregion/elevation/elevationcolorramp.lyr) to assign same values as used in the more detailed colorized hillshade created from the Lidar data. |