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Western Oregon Vegetation Mapping Project. NASA Land-Cover Land-Use Change (LCLUC) and Terrestrial Ecology ProgramUSDA Forest Service PNW Research StationOregon State UniversityH. J. Andrews LTER siteMapping forest cover and stand replacement disturbance patternsCreating carbon flux models to c
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1. GIS and Remote Sensing Methods for Mapping Forests: Lessons from the Western Oregon Vegetation Mapping Project Doug R. Oetter, Georgia College & State University
Warren B. Cohen, USDA Forest Service
Thomas K. Maiersperger, USDA Forest Service
Maria Fiorella, Pacific Meridian Resources
2. Western Oregon Vegetation Mapping Project NASA Land-Cover Land-Use Change (LCLUC) and Terrestrial Ecology Program
USDA Forest Service PNW Research Station
Oregon State University
H. J. Andrews LTER site
Mapping forest cover and stand replacement disturbance patterns
Creating carbon flux models to characterize trends in carbon storage across major forest biomes (Pacific NW and NW Russia)
3. Project Remote Sensing Component Forest Cover
Forest Composition
Forest Age/Size
Harvesting/Fire Patterns
4. Forest Mapping Methodology Develop reference information from ground sample and aerial photography sources
Incorporate spatial data into GIS linked to plot data
Extract spectral signatures from satellite images for each plot
Regression modeling in core scene to infer explanatory relationships
Test predictive models using independent data
Extend models from core image to adjacent scenes
Map generation
5. Forest Mapping Study Design
6. Landsat Thematic Mapper (TM) Scenes Core scene
Path 46, Row 29 (1988)
Subsequent scenes grouped by ecosystem
Coast Range
West Cascades
Klamath Mountains
7. Tasseled Cap Transformation Six TM visible and infra-red bands collapsed into three orthogonal bands
Related to physical variation in Brightness, Greenness, and Wetness:
Brightness: Amount of Spectral Reflection
10.3695 + .2909*(b1) + .2493*(b2) + .4806*(b3) + .5568*(b4) + .4438*(b5) + .1706*(b7)
Greenness: Presence of Green Vegetation
-.7310 - .2728*(b1) - .2174*(b2) - .5508*(b3) + .7221(b4) + .0733*(b5) - .1648*(b7)
Wetness: Soil Moisture and Canopy Development
-3.3828 + .1446*(b1) + .1761*(b2) + .3322*(b3) + .3396*(b4) - .6210*(b5) - .4186*(b7)
8. Feature Space
9. Ground Data Percent Forest Cover
1690 photo-interpreted polygons
Conifer vs. Hardwoods
USFS, BLM, ODOF photos (1986-89)
Conifer Age
100 PNW Research Station field measurements
434 USFS, BLM field measurements and inventories
Conifer Crown Diameter
560 photo-interpreted polygons
USFS, BLM, ODOF photos (1986-89)
10. Study Plots
11. Statistical Analysis Scatter Plots
Independent Variable Transformation
Max R, Stepwise Regression
Model Testing
Outlier Removal
Model Improvement
12. Removal of Outliers Digitizing Errors
Edge Pixels
Temporal Cover Change between image and reference
Clearcuts
Grasslands
Snow
Incorrect Interpretation
Data Omissions
13. Core Scene Predictive Models Percent Total Cover
TOTCOV = 9.8996*WET + 7.1073*GREEN - 0.0559*GW - 11.2856
Percent Conifer Cover
CON = 1.5153*BRITE + 0.0420*WET2 - 0.0244*GW - 200.8083
Conifer Age
Log10(AGE) = 56.0037 - 0.4194*WET - 1.0621*BRITE + 0.0082*BW
Conifer Visible Crown Diameter
Log10(VCD) = 16.0889 - 0.1259*WET -0.0009*BW + 0.0007*BG
14. Scene Extension
15. Independent Model Testing
16. Western Oregon Vegetation Map
17. Conifer Age Map
18. Conifer Visible Crown Diameter Map
19. Disturbance Methodology Multiple scenes from six dates:
Multi-Spectral Sensor: 1972, 1977, 1984
Thematic Mapper: 1988, 1991, 1995
Divided WOV region into 21 scenes
Tasseled cap (BG for MSS; BGW for TM)
Layer stack into 15-band image
Unsupervised classification captures change
Filtering to remove edge and single pixels
Manual re-coding of fires
20. Stand Replacement Disturbance Map
21. Potential Uses of Digital Forest Cover Images Wildlife Biology
Stream Ecology
Forest Planning
Landscape Ecology
Economic Modeling
Regional Carbon Flux Models
22. Transition to Southeastern Forests Methodologies developed for Western Oregon should apply to Southeast forests
Necessary information:
Field-based inventories
Aerial photographs
Satellite imagery
Different environments ? Different approaches
Improvements in regression methods and change detection strategies
Satellite information can be very powerful when incorporated with a robust ground reference data set!
23. Further Information Cohen, W B, T K Maiersperger, T A Spies, D R Oetter. 2001. Modeling forest cover attributes as continuous variables in a regional context with Thematic Mapper data. International Journal of Remote Sensing 22(12):2279-2310.
Cohen, W B, T A Spies, R J Alig, D R Oetter, T K Maiersperger, M Fiorella. 2002. Characterizing 23 years (1972-1995) of stand replacement disturbance in western Oregon forests with Landsat imagery. Ecosystems 5:122-137.
http://www.fsl.orst.edu/larse/wov/88wov.html