GIS Data Description - for full metadata click on Title hot link
Washington State Spatial Information Clearinghouse
| Title | Abstract |
| Planimetric information for Cowlitz County consists of a comprehensive set of digital features stereo-digitized from five (5) ortho photography contracts flown in 1968(1), 1995(1) and 1996(3). The level of planimetric detail derived from these flights varies from project to project based on three contracted map scale accuracies of 1"=50' (1:600), 1"=100' (1:1200) and 1"=200' (1:2400). Typical planimetric features consists of natural and cultural features as water bodies, road improvements, building foot prints and utilities. The 1968 planimetrics that cover major portions of the cities of Kelso and Longview and the planimetrics that cover portions of Kalama City (flown in 1996) are more comprehensive than those generally produced in 1995 and 1996. | |
| Digital orthophotography for Cowlitz County was derived from a combination of private contracts with aerial mapping firms, and from federal and state sources. Digital orthophoto products available in Cowlitz County were processed from: 1. Orthophotography flown in 1995, and 1996 for 1"=100' (1:1200) and 1"=200' (1:2400) mapping 2. Ortho photography flown by the Army Corps of Engineers in 1996 and acquired by Cowlitz County as part of a partnership agreement for 1"=200' (1:2400) mapping and 3. Digital Quads, acquired from the State Of Washington, Department of Natural Resources, processed in 1997 that were designed to meet or exceed the (map) accuracy specifications of the USGS 7.5 minute quads. | |
| Two surveys, conducted (by county staff)
under the supervision of a licensed surveyor in the Cowlitz County GIS department, were
performed to provide county-wide GPS control network constrained to an
existing Washington High Precision Network (HPN) stations. The County surveys comply with
the Federal Geodetic Control Committee’s Geometric Geodetic Accuracy Standards and
Specifications for Using GPS Relative Positioning Techniques Version 5.0 dated May 11,
1988 for Group C, Order 1. Both surveys are on record in the Cowlitz County’s
Auditor’s Office. In hard copy form, a detailed description report, defines
attributes for each geodetic control point.
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| Political /Administrative
boundaries for Cowlitz County reflect the geographic boundaries of more than 16
separate taxing, political, and administrative districts. Political/Administrative
Districts for Cowlitz County, when complete will consists of a comprehensive set of
homogeneous, geographic boundaries and text, that will overlay and coincide with the
boundaries and /or line features of the cadastral or planimetric coverages. The layers are
being digitally compiled as the base layers of the GIS are being built with much of the
work still in progress. Ultimately, more than 16 separate maps will be digitally converted
by Cowlitz County and its "project partners" who have joined with Cowlitz County
to build the GIS political layers.
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| Raster Images for
Cowlitz County consists of two types. The first type consists of more than 1100 raster
images of vector drawn cadastral and environmental maps registered to State Plane
Coordinates. The second type of raster image, not yet available, will consists of
unregistered, raster images of "assessor’ house sheets", appraisal photos,
plats, and other relevant images of legal records and documents attached to a database
record in the GIS.
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| Transportation facilities
for Cowlitz County consists of various features (points) linked together to form distinct,
fully attributed, utility, transportation networks county wide. The location of each
facility and its corresponding network will be digitally compiled as the base layers of
the GIS are built, with much of the work still in progress. Ultimately, numerous
transportation layers and related networks will be digitally converted by Cowlitz County
and its "project partners" who have joined with Cowlitz County to build the GIS
transportation layers.
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| Utility (Facilities) for
Cowlitz County consists of various features (points) linked together to form distinct,
fully attributed, utility and communication networks county wide. The location of each
facility and its corresponding network will be digitally compiled as the base layers of
the GIS are built, with much of the work still in progress. Ultimately, more than 7
separate utilities and various other communication networks will be digitally converted by
Cowlitz County and its "project partners" who have joined with Cowlitz County to
build the GIS utility layers.
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| Topographic information
for Cowlitz County has been derived from a combination of private contracts with aerial
mapping firms, and from federal and state sources. Topographic data products available in
Cowlitz County were processed from: 1. Ortho photography flown in 1995, and 1996 that produced raw DTM , and finished contour lines (in selected areas) based on three different map scales 2. Ortho photography flown by the Army Corps of Engineers in 1996 and acquired by Cowlitz County as part of a partnership agreement that produced raw DTM and finished contours and 3. DEM data, acquired from the State of Washington processed in 1997 that is a digital representation to the published USGS 7.5 minute quads contours. |
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| Cadastral information
for Cowlitz County consists of platted and un platted parcel boundaries, rights of way,
easements and other associated legal layers that will ultimately be digitally converted to
replace more than 1100 Assessor’s hand drawn map sheets. When complete, the cadastral
information for Cowlitz County will build the foundation for a shared, multi-purpose
Geographic Information System of high quality. Because the existing plats and maps in Cowlitz County were generally unsuitable to achieve the map accuracy needed, the Cowlitz County GIS Department in 1992 commenced a process to rebuild the legal cadastral layers from original records. To date nearly 50% of the tax parcels are converted as CAD drawing files and ArcInfo(R) coverages and as raster images. (See browse graphic for locations of completed work). To provide an immediate and complete set of Assessor’s maps for public and private use, more than 1100 paper maps were scanned as images and bundled together in a commercial software package for general viewing, plotting and distribution. This set of images are being replaced one by one as new cadastral maps are rebuilt by the GIS department and then converted to raster images. All cadastral maps in use are being maintained periodically by a joint effort between the Assessor and GIS departments |
Metadata Browse Page hosted by Washington
State Geographic Information Council
(WAGIC)
June 24, 1999