Vegetation - Suisun Marsh - 2015 [ds2676] GIS Dataset

To create the 2015 Suisun Marsh vegetation map, vegetation was interpreted from a mosaic of the true color imagery that was flown at 1:9600 (awaiting confirmation on scale but we believe this to be true) on June 15, 2015 and delivered to VegCAMP in October 2015. Polygons were delineated using heads-up digitizing (i.e., a photo interpreter manually drew polygons around each stand of vegetation) in ArcMAP 10.3 and polygon attributes were recorded within a personal geodatabase. In 2009, staff from the DWRs Mapping & Photogrammetry Section measured the positions of permanent residual features identified both in photographs and on the ground using Garmin 76CSx handheld GPS units. The published accuracy for these units is typically less than 5 meters. A total of 51 control points were measured and used to process the 2009 imagery, which resulted in an ortho-mosaic that closely agreed with NAIP digital orthorectified quarter quadrangle (DOQQ) aerial photography. The same method and control points were used to process the 2012 and 2015 imagery in order to produce vegetation maps that are spatially comparable (awaiting confirmation but we believe this to be true). Refer to VegCAMP (2012) for a complete description of the methods used for improving the spatial accuracy of the imagery. All attributes were interpreted using the Suisun Marsh 2015 imagery as the base imagery. The photo interpreters used all available ancillary information to make the best decision for each attribute. Information was obtained from sources such as field surveys, reconnaissance points, and field photos from all mapping years. Several other imagery sources were used as ancillary data, including the 2015 NAIP, 2015 NAIP CIR, all imagery available through Google Earth (including street view), Bing, and Digital Globe, and the 1999, 2003, 2006, 2009, and 2012 Suisun Marsh imagery. Minimum mapping unit (mmu): Typically, the minimum mapping size is 0.25 acre. However, the photo interpreters use their best judgment to determine if a stand below 0.25 acres should be separately delineated. A new occurrence of any non-native species of concern, such as Phragmites australis, Arundo donax, Carpobrotus edulis, Eucalyptus spp., and Lepidium latifolium, would be an example of when a polygon smaller than 0.25 acre would be appropriate. Additionally, the minimum mapping unit was 0.009 acre (400 square feet) for the Blacklock restoration project area. Minimum mapping width: There are many long narrow polygons within the Suisun Marsh study area, most of which are roads, ditches, levees and sloughs. The minimum mapping width is typically 10 feet; however, if small sections of a stand fell below the minimum width, the polygon would not be split. This mapping cycle included the collection of 340 reconnaissance points that were collected in June and July of 2015, except for two collected in May of 2016. The vegetation mapping classification used for this project is based on the vegetation classification created in 1999 (Keeler-Wolf et al. 2000). The names of the mapping units have been updated over the years to reflect current nomenclature and/or current understanding of vegetation classification. We used the same map classes for the 2015 map as were used as for the 2012 map for the original mapping. However, as discussed in detail under Accuracy Assessment, below, we combined some classes that were not possible to consistently distinguish on the imagery to create a revised classification. The 2015 map has both the 2012 attributes and the crosswalked, revised 2015 type attributes. In addition to the mapping unit, several other attributes are assigned to each polygon: percent vegetation cover, average vegetation height, degree of human disturbance, method of interpretation, habitat, and management region. For this update, we have added an attribute denoting the presence of Lepidium latifolium in the polygon, as discussed further below. An accuracy assessment was conducted on the 2015 map based on 290 field samples collected in summer of 2016. The users accuracy was 79.4% and the producers accuracy was 83.7% . Because the state standard for map accuracy is 80%, we explored using higher levels of the classification hierarchy while still maintaining important information. After consulting with the Environmental Coordination Advisory Team (ECAT), we have reduced the number of map classes. Reassigning map classes per the revised map classification improved users accuracy to 84.3% and producers to 85.9%.

* Processing environment Microsoft Windows 10 Version 10.0 (Build 19044) ; Esri ArcGIS 12.8.3.29751

Credits

Vegetation Classification and Mapping Program (VegCAMP), Department of Fish and Wildlife.

ArcGIS item properties

* Name ds2676
* Location file://\\geodata.\bios\WorkArea\BIOSOnline\Refresh\TODOData\BIOSOnlineData.gdb

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Extents

Extent

Description

Extent

Geographic extent

Extent in the item's coordinate system

* West longitude -186817.010200
* East longitude -162061.247000
* South latitude 4530.660300
* North latitude 27702.946600
* Extent contains the resource Yes

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Resource Points of Contact

Point of contact

Individual's name VegCAMP (Vegetation Classification and Mapping Program)
Organization's name Department of Fish and Wildlife
Contact's position Vegetation Classification and Mapping Program
Contact's role point of contact

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Resource Constraints

Constraints

Limitations of use

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Spatial Reference

ArcGIS coordinate system

* Type Projected
* Geographic coordinate reference GCS_North_American_1983
* Projection NAD_1983_California_Teale_Albers
* Coordinate reference details

Reference system identifier

* Value 3310
* Codespace EPSG
* Version 6.8(9.2.0)

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Spatial Data Properties

Vector

* Level of topology for this dataset geometry only
Geometric objects

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ArcGIS Feature Class Properties

Feature class name ds2676

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Geoprocessing history

Process

Date 2022-04-1214:30:26
Tool location c:\program files\arcgis\pro\Resources\ArcToolbox\toolboxes\Conversion Tools.tbx\FeatureClassToFeatureClass
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Include in lineage when exporting metadata No

Process

Date 2022-04-1214:30:45
Tool location c:\program files\arcgis\pro\Resources\ArcToolbox\toolboxes\Data Management Tools.tbx\Project
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Date 2022-04-1214:30:54
Tool location c:\program files\arcgis\pro\Resources\ArcToolbox\toolboxes\Data Management Tools.tbx\Rename
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Include in lineage when exporting metadata No