Top of Bank
|Feature Dataset Name||STAND-ALONE|
|Originator||City of Portland|
|Bureau||Bureau of Planning and Sustainability|
|Abstract|| Lines representing top-of-bank of major rivers and streams in the Portland region (where mapped). River top of bank derived from 2014 LiDAR using an automated mapping method explained in the process steps below. River top of bank will be completely mapped by early 2017. Columbia Slough top of bank derived from visual interpretation of aerial photos and 2007 LiDAR data. Mapping will be expanded over time using LiDAR data and field surveys. |
|Purpose||For locating top-of-bank in the Portland region|
|Supplemental Information|| Refer to the City of Portland Zoning Code definitions for a definition of top of bank, and how it is measured. |
|Last Dataset Update||05/04/2020 13:43|
|Last Source Update||05/04/2020 07:13|
|Maintenance/Update Frequency||As needed|
|Extent||City of Portland|
|Shape Type||Poly Line|
|Horizontal Position Accuracy||Mapped using LiDAR digital elevation model (DEM) and, where manually identified, aerial photos as reference. Refer to the LiDAR data and aerial photo metadata for specific information about horizontal accuracy.|
|Horizontal Position Accuracy Link|
|North Bounding Coordinate||729081.39895013|
|South Bounding Coordinate||676519.185039371|
|East Bounding Coordinate||7696976.957021|
|West Bounding Coordinate||7617373.25853018|
|Theme Keyword(s)||top-of-bank, streams, rivers|
|Theme Keyword Thesaurus||None|
|Place Keyword(s)||Portland, Multnomah County, Washington County, Clackamas County, Oregon|
|Place Keyword Thesaurus||None|
|Access Constraints||Available for Public Use|
|Use Constraints|| These data are distributed under the terms of the City of Portland Data Distribution Policy. Care was taken in the creation of this data but it is provided "as is". |
The City of Portland cannot accept any responsibility for errors, omissions, or positional accuracy.
|Source Dataset Type||File Geodatabase|
|Distribution|| Grid: State plane coordinate system 1983(91). |
Units: International feet
Datum: North American Datum of 1983/1991 (HPGN)
Liability: The information in this file was derived from digital databases on the City of Portland GIS. Care was taken in the creation of this file. The City cannot accept any responsibility for errors, omissions, or positional accuracy. There are no warranties, expressed or implied.
Format: Shapefile or File Geodatabase Feature Class - Data will be provided via City of Portland FTP Site.
Online Resource: http://portlandmaps.com/opendata
Online Instructions: City of Portland Public/Open Data is distributed via the PortlandMaps Open Data Site - http://portlandmaps.com/opendata. Data not available on the PortlandMaps Open Data site can be requested by contacting the City of Portland CGIS Group - email@example.com
Transfer Size: varies
SPCS Zone Identifier: 5076
| File(s) |
|01/01/2010|| Manual mapping of top of bank (Columbia Slough) |
Top of bank in parts of the Columbia Slough was manually mapped by the Bureau of Environmental Services in 2010 using the 2005 LiDAR DEM, the 2005 LiDAR hillshade, and 2010 6" aerials as reference. This mapping will eventually be updated with results from the automated mapping method.
|02/01/2016|| Automated mapping of top of bank |
Top of bank was mapped using the 2014 LiDAR digital elevation model (DEM), the LiDAR-derived ordinary high water line, and a geoprocessing script that automatically identifies top of bank based on the Zoning Code definition of top of bank. The script also removes "Noise" in the raw mapping output by applying several generalization tools to the raw output.
The mapping script is available upon request.
|Column Sort||Column Name||Column Alias||Column Type||Column Size||Domain Value(s)||Column Description||1||OBJECTID||OBJECTID||Integer||4||A unique software ID for each polygon. May change when data is modified.||1||SOURCE||Reference Source||String||60|| |
|The reference source for the mapped top-of-bank||1||SOURCE_REF||Reference Source Details||String||30|| |
|Any additional reference information regarding the mapping source (LiDAR flight date, survey information, etc.)||1||MODIFIER||Modified By||String||15|| |
|Last organization to edit the top-of-bank lines||1||MOD_NAME||Modifier Name||String||15||Initials of the last person to edit the top-of-bank line||1||MOD_DATE||Modification Date||Date||8||Date of the last modification||1||CREATED_BY||Created By||String||50||Name of the organization that originally created the top-of-bank line. Same domain as the "MODIFIER" attribute||1||CREATEDATE||Creation Date||Date||8||Date the top-of-bank line was originally created.||1||FIELD_DATE||Field Date||Date||8||Date of any field visit or survey.||1||REVIEW||Flag for Review?||String||5||Indicates whether the top-of-bank line needs further review (i.e., the mapped location is approximate).||1||NOTES||NOTES||String||150||Any notes related to the top-of-bank line||1||IS_TOB||Is TOB?||String||5||"True" indicates the line represents a top-of-bank; all other lines are used to create polygon features for modeling purposes.|