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Urban Tree Canopy Change Assessment for Southern Oahu
Wai Lee*, Sean MacFaden, Jarlath O’Neil-Dunne, and Teresa Trueman-Madriaga*
University of Vermont, Smart Trees Pacific*
Tree Canopy (TC) Assessments
USDA Forest Service/University of Vermont
Summarize Existing and Potential TC
>70 Assessments, U.S. and Canada
Increasingly larger areas (e.g., metro areas, counties, states)
Pictometry International Corp
How much tree canopy do we have?
How much room is there to plant trees?
Change Detection
Municipal Investments in Tree Canopy
What Are Tree-canopy Trends?
Second-generation LiDAR Collections
Updated UTC Assessments
Oahu Urban Tree Canopy Assessment - 2010
Methods
Multispectral Imagery and LiDAR
Thematic Data
Object-based Image Analysis
Map Canopy to Scale of Individual Trees
Map Other Primary Land-cover Features
Wildlife Habitat Modeling
Worldview-2
2010
1.65-ft (0.50-m)
8 bands (Visible, Near Infrared, et al.)
Worldview-2
LiDARLight Detection And Ranging
Courtesy of Dodson & Associates
X = 477589.675Y = 786620.334
Z = 532
X = 47780.122Y = 786621.913
Z = 384
Digital Surface Model (DSM)
Digital Elevation Model (DEM)
Normalized Digital Surface Model (nDSM)
LiDAR Intensity
LiDAR – 2010 UTC Assessment
2009
LiDAR Processed by USGS\NGA
3.281-ft (1-m) surface models
nDSM and Intensity
Thematic Data
Building Footprints, Hydrology, Runways
Roadbed Delineations Ideal
Centerlines
Estimate Roadbeds
Object-based Image Analysis
Objects Rather Than Pixels
Context and Texture
Data Fusion – raster, vector, LiDAR
eCognition – Enterprise Processing
Tree CanopyGrass/ShrubBare EarthWaterBuildingsRoadsOther Paved Surfaces
Automated Feature Extraction (eCognition)
Segmentation
Add Thematic Buildings and Water
Resolve Building Edge Discrepancies
Add Canopy Overhanging Buildings
Cleanup and Morphology
Remaining Classes: Grass Vs. Impervious
Estimate Roads and Add to Classification
Finalize Classes and More Cleanup
Manual Corrections
Fix Obvious Inconsistencies
Final Product
Grass/ShrubBare SoilOther Paved
Tree Canopy
Exis
tin
g
Poss
ible
• 76,761 acres of land in urban zone (excludes water)
• 15,274 acres of Existing UTC
• 27,224 acres of Possible UTC that is grass/shrub
• 13,760 acres of Possible UTC that is impervious (includes AG, Bare Soil)
• 20,613 acres is not suitable for tree canopy (buildings, roads)
Oahu Urban Tree Canopy Assessment - 2013
LiDAR – 2013 UTC Assessment
2013
LiDAR Processed by UVM SAL
3.281-ft (1-m) surface models
Some gaps in mountainous areas
LiDAR Coverage
Change Detection
Next Steps
Continue Rule-set Development
Manual Corrections
2013 Land-cover Map
Updated UTC Report
Urban Tree Canopy Change Assessment for Southern Oahu
Funding Provided by USDA Forest Service
University of Vermont, Smart Trees Pacific
Pictometry International Corp
Urban Tree Canopy Change Detection Assessment for Southern Oahu
http://letters-sal.blogspot.comhttp://nrs.fed.us./urban/utchttp://smarttreespacific.org
[email protected]@uvm.edu
[email protected]@hawaii.rr.com
University of Vermont, Smart Trees Pacific
Pictometry International Corp
