Remote Sensing of Fire Severity in Interior Alaska
(some of the time)
Remote Sensing of Fire Severity in Interior Alaska
(some of the time)
Dave Verbyla
Dept. of Forest Sciences, UAF
Email: [email protected]
Dave Verbyla
Dept. of Forest Sciences, UAF
Email: [email protected]
Field Estimates : CBI
Field Estimate
Remotely
Sensed
Index
2 Upland Black Spruce Burns
Yukon Charley 1999
• Fire start mid-June• NBR 9-Sept
CBI-NBR trend:• R2 = 0.81, n=32• R2 = 0.64, n=47
Boundary 2004
• Fire start mid-June• NBR 6-Sept
CBI-NBR trend:• R2 = 0.30, n=32• R2 = 0.43, n=28• R2 = 0.29, n=73
Saturation of Spectral Response?
NIR reflectance
SWIR
reflectance
dNBR = 797dNBR = 672
dNBR = 913
Fire Severity Trends
1980s Satellite Data
1990s Satellite Data
2000s Satellite Data
NBR
4-Aug-2004Sun Elevation: 36o
Azimuth: 165o
NBR
4-Aug-2004Sun Elevation: 36o
Azimuth: 165o
NBR
6-Sept-2004Sun Elevation: 30o
Azimuth: 166o
NBR
6-Sept-2004Sun Elevation: 30o
Azimuth: 166o
Summary
• Remote sensing estimates best across wide range of
severity
• Unreliable to estimate fire severity among burns or
across time
• Underestimate fire severity in valley bottoms, N-facing
slopes
• Estimates should be calibrated by vegetation type