1. Analysis of Forest Fire Disturbance in the Western US Using Landsat Time Series Images: 1985-2005 Haley Wicklein Advisors: Jim Collatz and Jeff Masek, Goddard Space Flight Center, NASA Research and Discover Program 2008

2. The First State of the Carbon Cycle Report (2007) King, Dilling, many others Motivation Forest carbon sink: ~ 270 ± 130 Mt C / yr Debate about relative importance of causal factors (disturbance, land use, climate change, etc) Future of sink is highly uncertain Landsat is an important tool for environmental monitoring

3. Objectives 1.Compare two disturbance products, identify fraction of disturbance that is fire 2.Use products to understand meteorological drivers of fire 3.Examine regrowth dynamics for fire vs. other types of disturbance

4. Joint project by Goddard, UMD, and USFS Landsat based data cubes (30m res) Annual record of forest disturbance events (logging, fire, insects, etc) from 1984-2005 Don’t distinguish between different types of disturbance North American Forest Dynamics Project (NAFD) Monitoring Trends in Burn Severity (MTBS) Joint project by USGS and USFS Maps burn severity and fire perimeter across the United States Uses before and after Landsat images to determine severity for all fires > 1000 acres Currently available for Pacific Northwest, CA, and parts of the Southwest Objective 1: Two Disturbance Maps Fire severityYear since disturbanceOregon Landsat cube

5. MTBS NAFD disturbance map Hash Rock Fire (2000) Ex: Oregon (1985-2005) Agreement 67% 16% 8% 6% Unburned - Low Low Moderate High 3% Disagreement 33% Disagreement between MTBS and NAFD

6. Cube Percent Fire of Total Disturbance Oregon27.3 California26.7 Idaho25.7 Utah7.7 Cube Statistics

7. Total Area Disturbed Area Burned Forest Disturbance Trends

8. Westerling et al. (2006) found Occurrence of Western wildfires largely governed by climate Attributed fire to: Warmer spring and summer temperature Reduced precipitation Reduced snowpack/ earlier spring snowmelt All lead to… Longer, drier summer fire season Objective 2: Climate Correlations

9. 1- (Precip/ PET) Fire Fire Trends Correlate with Aridity Index 1=dry, 0=wet

10. Objective 3: Regrowth dynamics

11. Normalized Difference Vegetation Index (NDVI) NIR – VIS NIR + VIS = NBR values range from -1 (bare soil) to 1 (very green) Normalized Burn Ratio (NBR) NIR – MIR NIR + MIR = [MTBS uses dNBR = pre NBR – post NBR] From: rangeview.arizona.edu WAVELENGTH VISMIRNIR NDVI values range from 0 (bare soil) to 1 (very green) Spectral Indices: NBR and NDVI

12. Jefferson Fire, 1996 Oregon (p45r29) 3922 acres High Moderate Low Unburned to Low Severity Class NBR and NDVI by Severity Class NBR NDVI *NBR and NDVI values from NAFD maps

13. Jefferson Fire Oregon (p45r29) 1996 3922 acres Spectral Recovery from Fire and Logging Disturbance Fire Logging Logging disturbance 1985

14. 1995 (year before fire) 1996 (year of fire)2005 (from: google earth) Do NBR and NDVI Provide Useful Ecological Information?

15. Hot and dry conditions necessary, but not sufficient for fire activity NDVI and NBR are good measures of timing and magnitude of disturbance, but canopy structure and height data (ex: LIDAR) is needed for useful information on ecological variables. Conclusions Only 7-30% of total disturbance in Western US is fire

16. Special Thanks to: Jim Collatz Jeff Masek Chris Williams The Research and Discover Program Questions?