City of Portland Vegetation | ||||||
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| Category | Environmental | |||||
| Feature Dataset Name | STAND-ALONE | |||||
| Item Name | Vegetation_pdx | |||||
| Database Type | SDE | |||||
| Originator | City of Portland | |||||
| Bureau | Bureau of Planning and Sustainability | |||||
| Publication Date | 12/16/2004 | |||||
| Abstract | Vegetation patches larger than 1/2 acre. Based on information from reference data sources including 6" resolution aerial photos, Parks and Recreation natural area assessments, and vegetation surveys along the banks of the Willamette and Columbia rivers. Vegetation patches area classified as forest, woodland, shrubland, or herbaceous. The mapping area includes all land within the City of Portland and the unincorporated parts of Multnomah County that are administered by the City of Portland. | |||||
| Purpose | For analyzing vegetation within Portland's riparian and upland areas. Developed as an input to the Bureau of Planning's GIS model for identifying significant natural resources. The key goals of the vegetation mapping project were 1) refine the location of vegetation "patches" of areas previously mapped by Metro; 2) incorporate vegetation maps generated by other agencies such as Portland Parks and Recreation and the Portland Bureau of Environmental Services and refine and improve that information where necessary; 3) map vegetation patches meeting Portland’s criteria for inclusion in the natural resource inventory a 1/2 acre minimum patch size versus the 1 to 2 acre patch size used by Metro for the regional dataset; 4) map all vegetation within a 1/4 mile of a surface stream, wetland, or regionally significant habitat resources included in Metro’s inventory; 5) classify the vegetation into four NVCS classes: forest, woodland, shrubland, and herbaceous; 6) further classify vegetation as either "natural/semi-natural" or "cultivated"; and 7) update, refine and improve the vegetation data annually as new aerial photos become available. | |||||
| Supplemental Information | Vegetation patches are updated with each year's aerial imagery. For more information, refer to the Bureau of Planning vegetation mapping project documentation at: http://www.portlandonline.com/shared/cfm/image.cfm?id=106047 This dataset is regularly updated. | |||||
| Last Dataset Update | 10/18/2023 10:23 | |||||
| Last Source Update | 10/17/2023 12:00 | |||||
| Maintenance/Update Frequency | As needed | |||||
| Extent | Clackamas County, Multnomah County, and Washington County, Oregon | |||||
| Data Type | Vector | |||||
| Shape Type | Polygon | |||||
| Feature Count | 6422 | |||||
| Horizontal Position Accuracy | All vegetation polygons created or revised by the Bureau of Planning were manually digitized from aerial photos, with a horizontal accuracy of +/- 5' or better. Original Metro vegetation and river habitat surveys digitized from 2000 and 2002 aerial photos, also at +/- 5' or better. Original Parks and Recreation vegetation units digitized from aerials and June 2002 multispectral imagery, with a horizontal accuracy of approximately +/- 10'. | |||||
| Horizontal Position Accuracy Link | Neither | |||||
| Progress | Complete | |||||
| North Bounding Coordinate | 731465.18766404 | |||||
| South Bounding Coordinate | 648037.562664047 | |||||
| East Bounding Coordinate | 7699357 | |||||
| West Bounding Coordinate | 7594610 | |||||
| Theme Keyword(s) | vegetation, patches, landcover, classification | |||||
| Theme Keyword Thesaurus | None | |||||
| Place Keyword(s) | Portland, Multnomah County | |||||
| 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 | |||||
| Output Geodatabase | PUBLICSAFETY.GDB | |||||
| 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 - maps@portlandoregon.gov Transfer Size: varies SPCS Zone Identifier: 5076 | |||||
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| 06/06/2004 | ORIGINAL DATA COMPILATION All existing vegetation data was first combined into a single dataset. Original sources for vegetation were: 1) Parks and Recreation natural areas assessment - vegetation patches as digitized by Parks natural area assessment team using 2002 and 2003 aerial photographs. Patches were visited in the field by Parks technicians, data about the patch was collected and recorded, and patch geometry and classes were changed as necessary based on the field data (avaialble online athttp://www.parks.ci.portland.or.us/NaturalAreas/veg_survey/default.asp). 2) River habitat mapping - wildlife habitat areas along the Willamette and Columbia rivers. Habitat areas were defined as plant species and plant communities that support avian, mammalian, reptilian and amphibian species that use the riparian area. The boundaries of the original habitat area were mapped using 1998 and 1999 aerial photos and field visits. Original mapping done on contract with Adolfson and Associates, Inc. Habitat areas updated by the Bureau of Planning using 2000 and 2001 aerial photos. 3) Metro 2000 vegetation - a simple vegetation landcover layer collected via interpretation of Metro's 2000 digital orthophotographs. Polygons were digitized around forest, woody non-forest vegetation, open space, and developed gaps. Forest landcover types were delineated for the entire area within the Metro Service District and all sections within one mile beyond the District boundary. Woody non-forest vegetation and open space was delineated only within 300 feet of a mapped stream within the Metro Service District and all sections within one mile beyond the District boundary. Minimum mapping unit was 1 acre. | |||||
| 06/06/2004 | MAPPING PROTOCOL 6" resolution aerial photos were the primary reference sources for identifying and revising vegetation patches. Vegetation patches are defined as an area of contiguous vegetation greater than 1/2 acre in size containing a distinct pattern, distribution, and composition of vegetation relative to surrounding vegetated and non-vegetated areas. The specific mapping criteria were: i. All vegetation patches visible on the aerial photos or classified as vegetation in a June 2002 multi-spectral image classification are reviewed for mapping. ii. Vegetation is mapped as it appears on the aerials. Conflicts between the various reference data sources are resolved in the following order (with higher numbers receiving highest priority) (see Reference Data Sources section below for specific information on reference data sources): 1. Metro’s regional vegetation map 2. Willamette & Columbia River habitat maps 3. Parks Bureau natural area assessment 4. Aerial photos iii. If the boundaries and class of a previously-mapped vegetation patch (Metro, Parks, etc.) are consistent with the aerials, then the patch is retained without modification. If a previously-mapped vegetation patch conflicts with the aerials, the geometry of the patch and/or the classification is modified to be consistent with the current aerial photos. iv. Non-vegetated areas (buildings, bare soil, etc.) contained within a larger vegetation patch are removed if the non-vegetated area is greater than 1/2 acre in size. Areas of less than 1/2 acre are removed from the patch when the area is clearly visible (i.e., not partially or completely obscured by canopy.) v. Patches are split when bisected by a 4-lane road or highway. Roads with less than 4 lanes split patches when they are clearly visible (i.e., there is no overhanging canopy) and the split will not result in patches of less than 1/2 acre. | |||||
| 06/07/2004 | VEGETATION CLASSIFICATION (CLASS) 2002 through 2004 aerial photos were also the primary references for classifying vegetation patches into the four "National Vegetation Classification System" (NVCS) classes defined as follows: 1) Forest: Trees with their crowns overlapping (generally forming 60-100% of cover.) 2) Woodland: Open stands of trees with crowns not usually touching, generally forming 25-60% of cover. Tree cover may be less than 25% in cases where it exceeds shrubland and herbaceous vegetation. 3) Shrubland: Shrubs generally greater than 0.5 m tall with individuals or clumps overlapping to not touching, generally forming more than 25% of cover with trees generally less than 25% of cover. Shrub cover may be less than 25% where it exceeds forest, woodland, and herbaceous vegetation. Vegetation dominated by woody vines (i.e., blackberry) is generally included in this class. 4) Herbaceous: Herbs (graminoids, forbs, ferns and shrubs less than 0.5m tall) dominant, generally forming at least 25% of cover. Herbaceous cover may be less than 25% where it exceeds forest, woodland and shrubland vegetation. This includes shrubs less than 0.5 m tall. Note that the 0.5 m height as a determination of class is difficult to apply consistently when using aerial photos as the primary reference source. It is often difficult to determine, without field verification, the exact height of shrubs and low-structure vegetation in a patch. Vegetation heights were therefore estimated by comparing the shadows cast with those of nearby features such as trees and houses. This is not possible in all areas. Therefore, the shrubland class tends to be applied to areas with larger, woody shrubs more easily visible on the current aerial photos. | |||||
| 06/07/2004 | VEGETATION CLASSIFICATION (SUBGROUP) Each vegetation patch was further classified into either “natural/semi-natural” or “cultivated” NVCS subgroups based on the following definitions : 1) Natural/Semi-Natural Vegetation: Natural vegetation is that which appears to be unmodified by human activities, occurring spontaneously without regular management, maintenance or planting. Semi-natural vegetation has a composition or structure that has been sufficiently altered by anthropogenic disturbances such that it no longer has the characteristics of natural vegetation assemblages found in comparable conditions the watershed. However, semi-natural vegetation is self-maintaining without significant human maintenance or management. This type of vegetation may be dominated by either native or non-native species. 2) Cultivated Vegetation: Vegetation that is consistent with traditional landscaping and is highly manicured and regularly (annually, semi-annually or more frequently) managed and maintained. Cultivated vegetation is often dominated by turf grasses and ornamental shrubs and trees. Cultivated vegetation typically has low species and structural diversity. It is assumed that cultivated areas are managed using a combination of mowing, pruning, fertilizers and pesticides. Residential yards, common areas, golf courses, parks and rights-of-way are included in this management class. In areas where agricultural land uses occur, cultivated fields and orchards are also included. Most vegetation, particularly within an urban setting, has been subjected to human disturbance. Even where these impacts are apparent, if the patch appears to be self-sufficient and displays patterns consistent with uninhibited and un-maintained growth, the patch is identified as natural/semi-natural. It is important to note that though natural/semi-natural areas may be dominated by native species, they need not be. An example of this would be a patch of Himalayan blackberry. Though these plants are not naturally-occurring in the Portland area, they are not generally planted or maintained and they distribute naturally, so they are mapped as an natual/semi-natural vegetation patch. The subgroup distinction is based on the pattern of plant distribution within the patch and the patch’s proximity to human features (such as houses and park infrastructure) rather than the type of vegetation present in the patch (which is often unknown). Also note that forest vegetation is always designated as semi-natural/natural. This is appropriate because forested areas are dominated by trees which provide significant ecologic functions, such as rainwater capture, nutrient uptake, organic inputs, wildlife cover, etc. In addition, the forest canopy itself is not regularly maintained. | |||||
Web Services
| Service | Description | Feature Access | Layer |
|---|---|---|---|
| BPS_Misc | Collection of micellaneous layers published to support Portland Bureau of Planning and Sustainability web mapping applications. | Dynamic | Vegetation |
Attribute Tables & Domains
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| Table Description | ||||||
| Table Jurisdiction | ||||||
| Column Sort | Column Name | Column Alias | Column Type | Column Size | Domain Value(s) | Column Description | 1 | SOURCE | Reference Source | String | 50 |
| | 1 | NVCS_CLASS | NVCS Class | String | 30 |
| | 1 | PATCH_DESC | Patch Description | String | 50 | | | 1 | NVCS_SUBCL | NVCS Subclass | String | 150 | | | 1 | NVCS_GROUP | NVCS Group | String | 200 | | | 1 | EDITOR | Editor Name | String | 30 | | | 1 | EDIT_DATE | Edit Date | Date | 8 | | | 1 | REVIEW | Needs Review? | String | 5 | | | 1 | FLD_DATE | Field Visit Date | Date | 8 | | | 1 | ORIG_EDITO | Original Editor | String | 15 | | | 1 | NVCS_SUBGR | NVCS Subgroup | String | 50 |
| | 1 | COMMENT | Comments | String | 254 | | | 1 | OBJECTID | OBJECTID | Integer | 10 | | |