Corvallis Forestry Sciences Laboratory
GIS Data Dictionary
Willamette River, Oregon, Active Channel 1995
Table of Contents
IDENTIFICATION_INFORMATION
Citation
Citation_Information
Originator: Stan Gregory, Oregon State University
Publication_Date: 20000315
Title: Willamette River, Oregon, Active Channel 1995
Geospatial_Data_Presentation_Form: Digital vector coverage
Publication_Information
Publication_Place: Corvallis, OR
Publisher: Pacific Northwest Ecosystem Research Consortium
Larger_Work_Citation
Citation_Information
Other_Citation_Details:
This coverage was created as part of the research undertaken by the Pacific
Northwest Ecosystem Research Consortium (http://osu.orst.edu/dept/pnw-erc)
funded by the U.S. Environmental Protection Agency under cooperative
agreement with Oregon State University #CR824682.
Online Linkage:
http://www.fsl.orst.edu/pnwerc/river/
Description
Abstract:
This map was created to delineate the extent of the active channel and other
floodplain features for the Willamette River, Oregon, for the year 1995. The
extent of the active channel and features such as alcoves, secondary channels,
remnant ponds, and islands were based on digital orthophotographs acquired in
1994-1995. Water bodies (primarily main and secondary channels) were digitized
from the photos and interpreted for channel type.
Purpose:
This polygon coverage will be used by land managers and government entities
within the Willamette Basin to assess past changes and possible future
management impacts on the river. It will also be used as part of a
research project designed to formulate future scenarios for growth in the
Willamette Valley (Pacific Northwest Ecosystem Research Consortium,
OSU, UO, EPA).
Supplemental_Information:
Procedures_Used:
The digital orthophotos upon which this coverage is based were produced at
Spencer B. Gross Mapping (SBG) in Portland, Oregon (http://www.sbgmaps.com)
under contract to US Army Corps of Engineers (USACE), Portland District.
The aerial photos were shot during August 1994 and September 1995. Although
portions of the river were thus photographed over one year apart, the winter
of 1994-1995 was relatively benign, and produced little in the way of channel
change due to flood events. These photographs had previously been used by
SBG for other projects of their own. An existing control network and
aerotriangulation solution were used by SBG to collect a digital terrain surface
from these photographs. A collection of mass points and breaklines was
collected by photogrammetric means using analytical and soft copy stereo
plotters. This collection of data was used to create a surface model that would
support orthorectified imagery. The orthophoto scan plates were scanned on a
Zeiss/Intergraph PS-1 at a resolution of 15um. The resulting imagery was
processed using the Intergraph suite of image processing software on an IGDS
6887. The resulting product was converted to TIFF format. These TIFF images
were received from the USACE in a set of 26 CD-ROMS.
The appropriate scenes were imported to Imagine 8.3 in their original state,
Oregon North State Plane Projection, GRS 1980 spheroid, NAD83 datum, 5076 zone,
2 foot pixel size. The scenes were stitched together, reprojected, and
resampled to UTM, Clarke 1866, NAD27, zone 10N, 1 meter pixel size. Files were
compressed using run-length compression. Pyramid layers were then added
externally.
Once the digital orthophotos were mosaiced and available in TIFF format, a
vector data layer was created. Imagine 8.3's on-screen vector digitizing module
was used. Base layers consisted of the digital orthophotos and the EPA River
Reach gis datalayer (at 1:100,000); the later was used only as a "locator".
Active channel features were manually digitized at 1:5,000. After completion of
each arc segment, vertices were added using either the spline tool or the line
tool in the vector module. The arc was then remagnified to 1:2,500 and
rechecked for correctness. In some cases, this meant moving or otherwise
modifying each vertex and/or segment. After all the segments had been digitized
and checked, the line coverage was draped over the original digital orthophotos
at 2 foot pixel size, and the arcs were again rechecked.
The outer edges of the active channel were determined by presence and type
of vegetation, or, in the case of urban areas, by the presence of floodwalls
and revetments. If no vegetation was visible on the orthophoto, the area
was presumed to lie within the active channel. Likewise, the presence of
annual plant species, grasses, and small shrubs (such as Salix spp.) were
presumed to lie within the boundaries of the active channel. Fringing
vegetation of woody trees and shrubs was generally considered to mark the
outer edge of the active channel. In most cases, the presence of high
stream banks, above the active channel, could easily be determined. In
areas of low contrast (due to exposure problems with the original aerial
photography), an estimate of active channel boundary was made using
hardcopy aerial photography as a guideline. In addition, where there
were gaps in the digital orthophoto coverage (particularly in the Portland
metropolitan area), the USGS 1:24,000 stream coverage was substituted.
In addition to digitizing the boundaries of the mainstem Willamette active
channel, smaller features such as sloughs, tributaries, side channels, secondary
channels (or braided channels), as well as off-channel ponds and lakes
(both natural and man-made) were added to the coverage. To be included,
water had to be visible on the digital orthophotos. For many of the
features with narrow channels, the presence of riparian vegetation could
obscure the water. In these cases, the feature may appear as a series of
disconnected arcs, reflecting the presence of this thick riparian canopy.
After the vector coverage was finished in Imagine, the file was read into
Arc/Info 7.2. The coverage was built and cleaned with a fuzzy tolerance of 1 m.
All problems with dangling arcs, pseudonodes, etc., were corrected in
Arc/Edit. This final line coverage was later converted to a polygon coverage
and attributed.
Active channel is defined as the portion of the river and floodplain
innundated at normal winter flood flows (i.e., those with an average return
interval of one to two years). The extent of this area was determined primarily
from vegetation type and presence.
Supplemental_Information:
Revisions:
This is the first version released outside the work group. No further
revisions are planned.
Time_Period_of_Content
Time_Period_Information
Range_of_Dates/Times
Beginning_Date: 19940000
Ending_Date: 19950000
Currentness_Reference: Digital photographs
Status
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain
Bounding_Coordinates
West_Bounding_Coordinate: -123.2954
East_Bounding_Coordinate: -122.5891
North_Bounding_Coordinate: 45.6549
South_Bounding_Coordinate: 44.0251
Keywords
Theme
Theme_Keyword_Thesaurus: None
Theme_Keyword: Floodplain
Theme_Keyword: River channel change
Theme_Keyword: Floodplain dynamics
Place
Place_Keyword_Thesaurus: None
Place_Keyword: Willamette River
Place_Keyword: Oregon
Place_Keyword: USA
Access_Constraints: none
Use_Constraints: none
Point_of_Contact
Contact_Information
Contact_Organization: Oregon State University
Contact_Person: Doug Oetter
Contact_Position: Faculty Research Assistant
Contact_Address
Address_Type: mailing and physical address
Address: Dept. of Forest Science
Oregon State University
City: Corvallis
State_or_Province: OR
Postal_Code: 97331
Country: USA
Contact_Voice_Telephone: 541-737-8417
Contact_Facsimile_Telephone: 541-758-7760
Contact_Electronic_Mail_Address: oetter@fsl.orst.edu
Data_Set_Credit
The aerial photography was solicitied and paid for by the US Army Corps of
Engineers using USACE specifications. Contracts were prepared and administered
by the USACE. SB Gross received the 1995 imagery, generated by Bergman, under
separate contract. Stitching and resampling of the digital orthophotography
TIFF files was completed by Doug Oetter, OSU Department of Forest Science.
Digitizing and interpretation of the active channel was performed by Linda
Ashkenas, OSU Department of Fisheries and Wildlife. OSU funding was provided by
the Pacific Northwest Ecosystem Research Consortium.
Security_Information
Security_Classification_System: None
Security_Classification: Unclassified
Security_Handling_Description: None
Native_Data_Set_Environment
Arc/Info version 7.2.1
/data/ibis/final/channel/ac1995p
DATA_QUALITY_INFORMATION
Attribute_Accuracy
Attribute_Accuracy_Report:
Features in this data set are located using the Universal
Transverse Mercator coordinate system and conform to Level 2
of FIPS 173 (4.1.3.5 Spatial Registration).
Logical_Consistency_Report:
Polygon and arc-node topology exists.
Completeness_Report:
Data set is complete.
Positional_Accuracy
Horizontal_Positional_Accuracy
Horizontal_Positional_Accuracy_Report:
Horizontal positional accuracy is unknown.
Vertical_Positional_Accuracy
Vertical_Positional_Accuracy_Report:
Vertical positional accuracy is unknown.
Lineage
Source_Information
Source_Citation
Originator: Spencer B. Gross Mapping
Publication_Date: 19950000
Title: 1995 Willamette River digital orthophotographs
Edition:
Publication_Information
Publication_Place: Portland, OR
Publisher: Spencer B. Gross Mapping
Source_Scale_Denominator: 2' pixels
Type_of_Source_Media: Digital orthophotographs
Source_Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19940000
Ending_Date: 19950000
Source_Currentness_Reference: Digital photographs
Source_Citation_Abbreviation:
Source_Contribution: Spencer B. Gross Mapping created the 1995 digital
orthophotographs of the Willamette River. The U. S. Army Corps of Engineers
made these images available to OSU.
Process_Step
Process_Description:
Creation of 1995 Willamette River digital orthophotographs.
Process_Date: 19960000
Process_Contact
Contact_Information
Contact_Organization: Spencer B. Gross Mapping
Contact_Person: Chris Aldrich
Contact_Position:
Contact_Address
Address_Type: mailing and physical address
Address: 13545 NW Science Park Dr.
City: Portland
State_or_Province: OR
Postal_Code: 97229
Country: USA
Contact_Voice_Telephone: 503-646-1733
Contact_Facsimile_Telephone:
Contact_Electronic_Mail_Address: chris@sbgmaps.com
Process_Step
Process_Description:
Distribution of Willamette River digital orthophotographs.
Process_Date: 19970000
Process_Contact
Contact_Information
Contact_Organization: U. S. Army Corps of Engineers
Contact_Person: Robert C. Peak
Contact_Position:
Contact_Address
Address_Type: mailing and physical address
Address: U. S. Army Corps of Engineers
333 SW 1st St.
City: Portland
State_or_Province: OR
Postal_Code: 97204
Country: USA
Contact_Voice_Telephone: 503-808-4856
Contact_Facsimile_Telephone:
Contact_Electronic_Mail_Address: robert.c.peak@usace.army.mil
Process_Step
Process_Description:
Translation of the digital orthophotographs to Imagine 8.3 files
in UTM projection.
Process_Date: 19980000
Process_Contact
Contact_Information
Contact_Organization: Oregon State University
Contact_Person: Doug Oetter
Contact_Position: Faculty Research Assistant
Contact_Address
Address_Type: mailing and physical address
Address: Dept. of Forest Science
Oregon State University
City: Corvallis
State_or_Province: OR
Postal_Code: 97331
Country: USA
Contact_Voice_Telephone: 541-737-8417
Contact_Facsimile_Telephone: 541-758-7760
Contact_Electronic_Mail_Address: oetter@fsl.orst.edu
Process_Step
Process_Description:
Digitizing and attributing coverage.
Process_Date: 19980000
Process_Contact
Contact_Information
Contact_Organization: Oregon State University
Contact_Person: Linda Ashkenas
Contact_Position: Senior Faculty Research Assistant
Contact_Address
Address_Type: mailing and physical address
Address: Dept. of Fish and Wildlife
Oregon State University
City: Corvallis
State_or_Province: OR
Postal_Code: 97331
Country: USA
Contact_Voice_Telephone: 541-737-1966
Contact_Facsimile_Telephone: 541-737-3590
Contact_Electronic_Mail_Address: linda.ashkenas@orst.edu
Cloud_Cover:
SPATIAL_DATA_ORGANIZATION_INFORMATION
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information
SDTS_Terms_Description
SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 734
SPATIAL_REFERENCE_INFORMATION
Grid_Coordinate_System
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal Transverse Mercator (UTM)
UTM_Zone_Number: 10
Planar_Coordinate_Information
Planar_Coordinate_Encoding_Method: Coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 1 m
Ordinate_Resolution: 1 m
Planar_Distance_Units: METERS
Geodetic_Model
Horizontal_Datum_Name: North American Datum 1927
Ellipsoid_Name: CLARKE1866
Semi-major_Axis: 6378206.4
Denominator_of_Flattening_Ratio: 294.98
ENTITY_AND_ATTRIBUTE_INFORMATION
Detailed_Description
Entity_Type
Entity_Type_Label: ac1995p.pat
Entity_Type_Definition: Polygon Attribute Table
Entity_Type_Definition_Source: None
Attribute
Attribute_Label: REACH
Attribute_Definition: Indication of river reach
Attribute_Definition_Source: User Defined
Attribute_Domain_Values
Range_Domain
Range_Domain_Minimum: 1
Range_Domain_Maximum: 7
Attribute_Domain_Values
Codeset_Domain
Attribute_Code: 1
Definition: Mouth to Willamette Falls, 0-36
Attribute_Code: 2
Definition: Willamette Falls to Molalla Confluence, 37-50
Attribute_Code: 3
Definition: Mollalla Confluence to Newberg, 51-71
Attribute_Code: 4
Definition: Newberg to Salem, 72-110
Attribute_Code: 5
Definition: Salem to Albany, 111-151
Attribute_Code: 6
Definition: Albany to Harrisburg, 152-201
Attribute_Code: 7
Definition: Harrisburg to Middle Fork Confluence, 202-227
Attribute
Attribute_Label: CODE
Attribute_Definition: Channel type code
Attribute_Definition_Source: User Defined
Attribute_Domain_Values
Range_Domain
Range_Domain_Minimum: 1
Range_Domain_Maximum: 11
Attribute_Domain_Values
Codeset_Domain
Attribute_Code: 1
Definition: Main active channel.
Attribute_Code: 3
Definition: Sloughs, alcoves where one end is connected to main channel.
Attribute_Code: 5
Definition: Side or secondary channel. Both ends connect to main channel.
Attribute_Code: 6
Definition: Remnant river feature -- within known floodplain. Disconnected
floodplain lakes, sloughs. No apparent connection to main river,
but within historical floodplain area based flood extent coverage.
Attribute_Code: 7
Definition: Remnant river feature -- outside known floodplain. Disconnected
floodplain lakes, sloughs. No apparent connection to main river,
and outside historical floodplain area based flood extent coverage.
Attribute_Code: 10
Definition: Tributary to Willamette River.
Attribute_Code: 11
Definition: Islands.
Attribute
Attribute_Label: DESCRIPTION
Attribute_Definition: Associated place name or river feature
Attribute_Definition_Source: User Defined
DISTRIBUTION_INFORMATION
Distributor
Contact_Information
Contact_Organization: Oregon State University
Contact_Person: Doug Oetter
Contact_Position: Faculty Research Assistant
Contact_Address
Address_Type: mailing and physical address
Address: Dept. of Forest Science
Oregon State University
City: Corvallis
State_or_Province: OR
Postal_Code: 97331
Country: USA
Contact_Voice_Telephone: 541-737-8417
Contact_Facsimile_Telephone: 541-758-7760
Contact_Electronic_Mail_Address: oetter@fsl.orst.edu
Resource_Description:
AC1995P
Distribution_Liability:
While strong efforts are made to ensure data set accuracy,
complete accuracy of every data set cannot be guaranteed.
Standard_Order_Process
Digital_Form
Digital_Transfer_Information
Format_Name:Gzipped ARC/Info Interchange file
Digital_Transfer_Option
Online_Option
Computer_Contact_Information
Network_Address: ftp.fsl.orst.edu
Network_Resource_Name:
/pub/pnwerc/river/ac1995p.e00.gz
Access_Instructions: anonymous ftp
Fees: none
METADATA_REFERENCE_INFORMATION
Metadata_Date: 20000315
Metadata_Review_Date:
Metadata_Contact
Contact_Information
Contact_Organization: Oregon State University
Contact_Person: Doug Oetter
Contact_Position: Faculty Research Assistant
Contact_Address
Address_Type: mailing and physical address
Address: Dept. of Forest Science
Oregon State University
City: Corvallis
State_or_Province: OR
Postal_Code: 97331
Country: USA
Contact_Voice_Telephone: 541-737-8417
Contact_Facsimile_Telephone: 541-758-7760
Contact_Electronic_Mail_Address: oetter@fsl.orst.edu
Metadata_Standard_Name: FGDC CSDGM
Metadata_Standard_Version: 19940608