ESTIMATING FIRE SEVERITY AND POST-FIRE FOREST RECOVERY USING MULTI-TEMPORAL VEGETATION INDICES DERIVED FROM LANDSAT 8 IMAGERY
Russell Zientek
https://www.uidaho.edu/news/climate-change/wildfire
INCREASING WILDFIRE LEVELS AND LONGER FIRE SEASONS
Source: NIFC
REMOTE SENSING FOR POST-FIRE ASSESSMENT AND MAPPING
https://www.researchgate.net/figure/Low-moderate-and-high-burn-severity-sites-in-California-CA-chaparral-Montana-MT_fig2_228354320
MEASURING RECOVERY
https://www.paysonroundup.com/news/forest_management_wildfires/hot-dry-forests-can-t-recover-from-wildfires/article_9e503660-9c86-5688-a5f8-ff9c66880dcc.html/
https://e360.yale.edu/features/does-a-fire-ravaged-forest-need-human-help-to-recover/
https://news.wisc.edu/drought-alters-recovery-of-rocky-mountain-forests-after-fire/
https://k96fm.com/um-study-suggests-climate-change-limits-forest-recovery-after-wildfires/
VEGETATION INDICES
Landsat 8 OLI/TIRS C2 L2 Bands
Red = Band 4 - µ0.64-0.67
NIR = Band 5 - µ0.85-0.88
SWIR1 = Band 6 - µ1.57-1.65
SWIR2 = Band 7 - µ2.11-2.29
PROJECT STUDY AREA
Wildfire | Start Date | Fire Size (acres) | Elevation Range (meters) | Elevation Mean (meters) | Vegeation Type |
Boulder | 8/11/2015 | 5,012 | 1550-2000 | 1750 | Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest and Woodland |
Crown | 8/17/2015 | 33,518 | 1010-2420 | 1860 | Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest and Woodland Nothern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest |
Jay Point | 8/17/2015 | 4,503 | 1020-2060 | 1490 | Northern Rocky Mountain Mesic Montane Mixed Conifer Forest Nothern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest |
Snowy Summit & Pete Forks | 8/14/2015 | 14,049 | 1230-1990 | 1600 | Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest and Woodland Northern Rocky Mountain Mesic Montane Mixed Conifer Forest |
Wash & Slide | 8/15/2015 | 47,053 | 460-2100 | 1130 | Northern Rocky Mountain Mesic Montane Mixed Conifer Forest Nothern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest |
IMAGERY AND DATA
Landsat 8 Satellite Imagery | https://earthexplorer.usgs.gov/ |
Description | Data |
Pre-fire Satellite Imagery | LC080410282014090501T1-SC20201121160345 |
Post-fire Satellite Imagery | LC080410282015092401T1-SC20201121180827 |
Post-fire + 1YR Satellite Imagery | LC080410282016091001T1-SC20201121160335 |
Post-fire + 3YR Satellite Imagery | LC080410282018081501T1-SC20201121160344 |
Post-fire + 5YR Satellite Imagery | LC080410282020080401T1-SC20201121160333 |
| |
Landfire | https://www.landfire.gov/ |
Description | Data |
2014 Expected Vegetation Type | US_140EVT |
2014 Canopy Base Density | US_140CBD |
2014 Canopy Base Height | US_140CBH |
2014 Mean Fire Return Interval | US_140MFRI |
2016 Expected Vegetation Type | US_200EVT |
2020 Canopy Base Density | US_200CBD_20 |
2020 Canopy Base Height | US_200CBH_20 |
| |
Wildfire Perimeters | https://data-nifc.opendata.arcgis.com |
Description | Data |
Wildfire Perimeters all years | Interagency_Fire_Perimeter_History_All_Years.shp |
| |
Elevation | https://viewer.nationalmap.gov/basic/#/ |
Description | Data |
30 Meter Digital Elevation Models | USGS_NED_13_n46w116_IMG |
30 Meter Digital Elevation Models | USGS_NED_13_n47w115_IMG |
30 Meter Digital Elevation Models | USGS_NED_13_n47w116_IMG |
ARCGIS PRO PROCESSING
BURN SEVERITY MAPS
INDICES BY WILDFIRE
Greenness Indices
Wetness Indices
INDICES BY BURN SEVERITY
INDICES BY BURN SEVERITY
DISCUSSION
2014 | | |
Percent | EVT Classname | EVT Subclass |
36% | Rocky Mountain Subalpine Mesic-Wet Spruce-Fir Forest and Woodland | Evergreen closed tree canopy |
23% | Northern Rocky Mountain Mesic Montane Mixed Conifer Forest | Evergreen closed tree canopy |
23% | Northern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest | Evergreen closed tree canopy |
7% | Dry-mesic Montane Douglas-fir Forest | Evergreen open tree canopy |
3% | Rocky Mountain Lodgepole Pine Forest | Evergreen closed tree canopy |
2016 | | |
Percent | EVT Classname | EVT Subclass |
27% | Recently Burned-Herb and Grass Cover | Perennial graminoid |
21% | Northern Rocky Mountain Mesic Montane Mixed Conifer Forest | Evergreen closed tree canopy |
19% | Recently Burned-Shrub Cover | Mixed evergreen-deciduous shrubland |
12% | Northern Rocky Mountain Dry-Mesic Montane Mixed Conifer Forest | Evergreen closed tree canopy |
6% | Rocky Mountain Lodgepole Pine Forest | Evergreen closed tree canopy |
CONCLUSIONS
Time-series vegetation indices derived from Landsat 8 imagery seem to provide one measure of recovery pertaining to vegetation cover.
Only NBR had longer recovery times and seemed to indicate that it may provide a good measure of forest structure and biomass recovery within the study area.
Field sampling is required to validate the results of the NBR findings.
While it is difficult for remote sensing to determine forest structure and dynamics, using remotely sensed imagery to aid in assessing recovery, especially over large areas, can be a useful tool.