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: D.Verbyla@uaf.edu

Dave Verbyla

Dept. of Forest Sciences, UAF

Email: D.Verbyla@uaf.edu

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