Urban Tree Canopy Change Assessment for Southern Oahu

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

wlee@smarttreespacific.orgSean.MacFaden@uvm.edu

Jarlath.Oneil-Dunne@uvm.eduttm@hawaii.rr.com

University of Vermont, Smart Trees Pacific

Pictometry International Corp