corrie hannah mentor: dr. stuart e. marsh, office of arid lands studies nasa space grant symposium...
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Corrie HannahMentor: Dr. Stuart E. Marsh, Office of Arid Lands Studies
NASA Space Grant Symposium
April 17, 2009
Arizona State University
Using Remote Sensing to Map and Manage Using Remote Sensing to Map and Manage Buffelgrass Infestations in Tucson and the Buffelgrass Infestations in Tucson and the
Santa Catalina MountainsSanta Catalina Mountains
What is Buffelgrass?What is Buffelgrass?
• Invasive species originally brought from Africa to the Americas for cattlegrazing
• Threatens to out-compete native species• Potential to transform the fireproof Arizona
Sonoran Desert into a burning savannah
National Fire Plan http://www.forestsandrangelands.gov
((Pennisetum ciliare)Pennisetum ciliare)
What is Remote Sensing?What is Remote Sensing?A science that uses satellite imagery and aerial
photography to identify features and natural processes on the Earth’s surface
ObjectivesObjectives• Identify a practical method of mapping and
managing buffelgrass in Southern Arizona • Determine benefits of different spectral
and spatial satellite and aerial imagery to locate buffelgrass
Identifying Remotely Sensed Identifying Remotely Sensed Imagery to Map BuffelgrassImagery to Map Buffelgrass
TypeType Spectral Resolution Spectral Resolution Spatial Spatial ResolutionResolution
PAGPAG Aerial Photography
3 color bands 1ft
DOQQDOQQ Aerial Photography
3 color bands plus near infrared
1m
LandsatLandsat Satellite Imagery
6 reflective bands 30m
ASTERASTER Satellite Imagery
3 color & near infrared/6 shortwave infrared bands
15m/30m
MethodsMethods• Identified remotely sensed imagery• Manually digitized high resolution aerial imagery• Located buffelgrass locations: Presence & Absense• Fieldwork! Validated digitized ground control points• Classified buffelgrass locations in images• Accuracy assessments
Area of Study: Santa Catalina Mountains North of Tucson
Heads-up DigitizingHeads-up Digitizing
Buffelgrass!!!
Supervised ClassificationsSupervised Classifications
1ft Aerial Image
30m ASTER Satellite Imagery
1m Aerial Image
30m Landsat Satellite Imagery
Red polygon areas indicate buffelgrass presence
Texture Filters and TopographyTexture Filters and Topography
1ft Aerial Image + Texture + Topography 1m Aerial Image + Texture + Topography
15m ASTER Satellite Image + Topography 30m Landsat Satellite Image + Topography
Red polygon areas indicate buffelgrass presence
Multi-temporal StacksMulti-temporal Stacks
15m ASTER scene composite: 4/22/2006 and 7/18/2006
15m ASTER scene composite: 7/18/2006 and 11/27/2008
15m ASTER scene composite + Topography: 4/22/2006 and 7/18/2006
15m ASTER scene composite + Topography: 7/18/2006 and 11/27/2008
Red polygon areas indicate buffelgrass presence
Binary Ensemble Binary Ensemble
Yellow = 5 or more models predict buffelgrass
Red = 10 or more models predict buffelgrass
Green/White = less than 5 models predict buffelgrass
A composite stack of the twenty classifications: buffelgrass presence or absence
Place where the most models were Place where the most models were successful at locating buffelgrasssuccessful at locating buffelgrass
Photo from the Field
1ft Aerial photography Binary Ensemble: Close-up
Place where most models were not as Place where most models were not as successful at locating buffelgrasssuccessful at locating buffelgrass
Photo from the Field
1ft Aerial photography Binary Ensemble: Close-up
Photo from the Field
1ft Aerial photography
Binary Ensemble: Close-up
Place where the most models were Place where the most models were successful at locating buffelgrasssuccessful at locating buffelgrass
ResultsResults
• High-resolution imagery was more reliable than moderate-resolution imagery at locating buffelgrass
• Manual digitization of the1ft aerial photography was the most accurate method of classifying buffelgrass
• Of the automated classified images, the 1ft aerial photography with topography and texture was the most accurate
ConclusionConclusionWe suggest that 1ft resolution or higher aerial
photography, which covers much of the infested areas surrounding Tucson, should be used to most
effectively map and manage buffelgrass infestations in the future.
AcknowledgementsAcknowledgements
• Aaryn D. OlssonAaryn D. Olsson• Kyle A. HartfieldKyle A. Hartfield• Stuart E. MarshStuart E. Marsh• Barron J. OrrBarron J. Orr• Grant CasadyGrant Casady• Arizona Remote Sensing CenterArizona Remote Sensing Center• Office of Arid Lands StudiesOffice of Arid Lands Studies• NASA Space Grant ConsortiumNASA Space Grant Consortium
Thank YouThank You