ArcGIS REST Services Directory
JSON

Layer: % '10-'19 Forest Gaps (Native Forest Lifeform) (ID:3)

View In:   Map Viewer

Name: % '10-'19 Forest Gaps (Native Forest Lifeform)

Display Field: OID_COPY

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: <div style="text-align:left;"><p style="font-size:12pt;"><span><span>Canopy gap analysis was conducted using Canopy Height Model (CHM) differencing, where analysts calculated the difference between the CHM value in 2019 minus the CHM value in 2010. This analysis was performed in Trimble</span></span><span><span>®</span></span><span><span> Ecogntion</span></span><span><span>®</span></span><span>, where the lidar CHM differencing was followed by noise removal to remove anomolous gaps. Very small gaps (&lt;40 square feet) were also removed to reduce ‘noise’ in the gap analysis. The resulting canopy gaps were reviewed by analysts, who removed ‘false positive’ gaps along the coast and in urban areas. The final canopy gap dataset was integrated into the vegetation map, where each stand was assigned an attribute for the percent of its woody canopy over 7 ft. that was a gap formed between ’10-’19. A second attribute provides information for the area of each forested stand’s largest contiguous gap. </span></p><p style="font-size:12pt;"><span><span>Areas were considered canopy gaps and mapped as such if their canopy height changed in one of the following ways between 2010 and 2019 at the 1-meter raster scale:</span></span></p><ul><li><p style="margin:4 0 12 0;"><span style="font-weight:bold;"><span>Low Gap</span></span><span><span>: Areas greater than or equal to 7 ft. in height in 2010 and less than 2 ft. in 2019 that lost more than 7 feet of canopy height between 2010 and 2019.</span></span></p></li><li><p style="margin:4 0 12 0;"><span style="font-weight:bold;"><span>Medium Gap</span></span><span><span>: Areas greater than or equal to 12 ft. in height in 2010 and less than 7 ft. In height in 2019.</span></span></p></li><li><p style="margin:4 0 12 0;"><span style="font-weight:bold;"><span>High Gap</span></span><span><span>: Areas greater than or equal to 15 ft. in height in 2010 that lost greater than 40 % of their total height between 2010 and 2019</span></span></p></li><li><p style="margin:4 0 12 0;"><span style="font-weight:bold;"><span>Very</span></span><span><span> </span></span><span style="font-weight:bold;"><span>High Gap</span></span><span><span>: Areas greater than or equal to 100 ft. in height in 2010 that lost greater than 25% of their total height between 2010 and 2019</span></span><span><span>.</span></span></p></li></ul><div style><span style="font-size:16px;">See Chapter 6 of the </span><a href="https://www.onetam.org/sites/default/files/pdfs/marin_regional_forest_health_strategy_2023.pdf" target="_blank">Marin Regional Forest Health Strategy</a><span style="font-size:16px;"> (Page 269 - Canopy Gaps) for more information.</span><br /></div><div style="font-size:12pt;"><p><span></span></p></div></div>

Copyright Text: GGNPC, One Tam, Tukman Geospatial

Min. Scale: 1155582

Max. Scale: 1128

Default Visibility: false

Max Record Count: 2000

Supported query Formats: JSON, geoJSON, PBF

Use Standardized Queries: True

Extent:

Drawing Info:

HasZ: false

HasM: false

Has Attachments: false

Has Geometry Properties: true

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Object ID Field: OBJECTID

Unique ID Field:

Global ID Field: GlobalID

Type ID Field: CANOPY_GAP_10_19_MANUAL

Fields:
Types:

Is Data Versioned: false

Has Contingent Values: false

Supports Rollback On Failure Parameter: true

Last Edit Date: 12/12/2023 8:00:29 PM

Schema Last Edit Date: 10/12/2023 10:18:42 PM

Data Last Edit Date: 10/12/2023 10:18:42 PM

Supported Operations:   Query   Query Pivot   Query Top Features   Query Analytic   Query Bins   Generate Renderer   Validate SQL   Get Estimates   ConvertFormat