Landscape-Scale Postfire Vegetative Condition Monitoring Using Multi- temporal Landsat Imagery on the Cerro Grande Fire

Transcription

1 Landscape-Scale Postfire Vegetative Condition Monitoring Using Multi- temporal Landsat Imagery on the Cerro Grande Fire RS 2006 : April 27, 2006 Salt Lake City, UT Jess T. Clark Remote Sensing Applications Center Gregory A. Kuyumjian Santa Fe National Forest

2 What: Vegetation Regeneration Monitoring Vegetation regeneration monitoring on a large fire using landscape-scale scale remotely sensed imagery Compare zones of the fire that had different levels and distributions of post-fire treatments applied Determine whether 1) one could monitor vegetation condition over time 2) one could monitor post-fire treatment trends on large fires at a landscape scale with low costs

3 Vegetation Regeneration What we needed: Monitoring Landsat 5 TM or 7 ETM+ Remote Sensing support Boots on the ground local knowledge ~$1500 / year Annual time commitment Some good luck

4 Cerro Grande Fire Ignited as prescribed fire May 4, 2000 Wildfire May 7 Contained June 6 Out September 22 Burned 17,400 Ha (~43,000 acres) Image courtesy Albuquerque Tribune

5 Ski Area Golf Course Airport LANL* *Los Alamos National Laboratory IKONOS 4m Color-IR Image Acquired May 20, 2000

6 Cerro Grande Recovery Post-fire five year monitoring effort: Anniversary Landsat ETM+ and TM imagery September 28, 1999 September 14, 2000 September 24, 2001 September 20, 2002 September 22, 2003 September 17, 2004 September 27, 2005 All co-registered and converted to reflectance

7 Vegetation Regeneration Monitoring North Zone: Rendija Canyon watershed and north 23,450 acres 11,200 acres attributed as high or moderate burn severity (48% of zone) South Zone: Pueblo Canyon watershed and south to include LANL 19,650 acres 6,700 acres attributed as high or moderate burn severity (34% of zone)

8 Landsat 7 ETM+ image acquired September 14, 2000, three months after containment. Clouds and shadows North Zone Los Alamos LANL South Zone

9 Prefire

10 2000

11 2001

12 2002

13 2003

14 2004

15 2005

16 Indices Used NDVI (Normalized Difference Vegetation Index) Highlights photosynthetic activity Calculated annually NRI (Normalized Regeneration Index) Compares NDVI values between fire and controls to quantify vegetation regeneration Calculated for inter-annual annual comparison Red NDVI = NIR Red + NIR NDVI fire NDVI control NRI = 1 + NDVI fire NDVI NDVI fire + NDVI NDVI control

17 NDVI Year to Year Controls Control Blues suggest more vibrant photosynthetic activity; tans suggest much less activity

18

19 Precipitation Patterns Dry years stunt or may reverse regeneration Wet years may result in increased regeneration Quemezon NRCS SNOTEL (9500 ) LANL (TA-6) Climate Station (7424 ) Annual Precipitation (in) Inches Quemezon SNOTEL Los Alamos Average Los Alamos Climate Station Quemezon Average

20 NDVI Values for Entire Fire Cerro Grande NDVI Trends NDVI Values All Controls Fire NDVI Year Three years of below avg. precipitation

21 Treatments by NRI Zone Treatment* South North Total Aerial Seeding >6,700 >11,200 21,080 Aerial Hydromulch ,184 Contour Felling 1,823 1,316 3,139 Straw Wattles ,265 Grade Control Straw Mulch 2, ,704 Raking Treatment Totals 5,880 2,647 8,532 Total Mulch Acres 3, ,888 Acres In Perimeter 19,650 23,450 ~43,000 Acres High & Mod 6,700 11,200 ~17,900 % Mulch (H&M) *Channel treatments not included

22 South Mulch Acres: 3,049 North Mulch Acres: 839 Straw Mulch Aerial Hydromulch LANL Mulch LANL Aerial Hydromulch

23 NDVI Values By Zone Cerro Grande NDVI Trends NDVI Values Year South Zone NDVI North Zone NDVI All Controls Change in Annual NDVI Years Delta NDVI North dndvi South dndvi Control dndvi

24 NRI Trends Cerro Grande NRI Trends NRI Value South Zone North Zone Year Change in Annual NRI Years Delta NRI North dnri South dnri -0.04

25 Vegetation Recovery Discussion NDVI values differ due to differences in acres of high and moderate severity between zones Differences in landcover type distributions More P-J P J in north than south, for example Extent of treatments in each zone were different More mortality of remaining vegetation in north Higher % of mulch in the south (both rapid greening (2001) and browning (2002) see delta NRI) Precipitation patterns

26 Cañon de Valle riparian scour Straw mulch applied July 2000, in south fork of Rendija Canyon (September 01, 2003) Ground Photo Monitoring 2003 BAER Treatments Cerro Grande Fire - Santa Fe National Forest NDVI Change with Aerial Hydromulch (blue) and 2001 Mulch Treatments (pink) Guaje Ridge 16 Guaje Canyon tree mortality Aerial hydromulch in Rendija Canyon as viewed from Guaje Ridge (September 20, 2003) Aerial hydromulch on north-facing slope of School Canyon (September 10, 2003) 1 Highly variable moisture conditions 12 Los Alamos Canyon riparian scour 15 Los Alamos Reservoir Los Alamos National Laboratory thinning New water tank Los Alamos County thinning Los Alamos Canyon tree mortality 12 Aerial hydromulch Los Alamos Canyon; top of slope above Los Alamos Reservoir (September 27, 2003) 2 13 M Straw mulch applied during July 2001, tributary to Los Alamos Canyon below Quemezon Trail Aerial hydromulch, July 2000, North Pueblo Canyon (Sept. 11, 2003) 8 4 Straw Mulch on Quemezon Trail (September 27, 2003) Straw mulch, June 2000 divide between Two Mile and Pajarito Canyons (August 14, 2003) (September 11, 2003) 3 14 N Straw mulch applied in Water Canyon, July 2000, above American Springs Road (September 22, 2003) Straw mulch, August 2001, North Pueblo Watershed (October 18, 2003) 6 9 Straw Mulch South Pueblo Canyon note oak in foreground (September 27, 2003) Raked and mulched, June 2000; headwaters of South Fork of Two Mile Canyon (August 14, 2003) Contour placed log in 2000 and straw mulch in 2001; along Pipeline Road (September 11, 2003) 4D 5 American Springs Road, July 2000; seeded, raked mulched, wattles and log erosion barriers (August 12, 2003) 7G 10 Aerial hydromulch above Los Alamos Reservoir (September 24, 2003) 15 O 16 Aerial seeding in 2000 on northfacing slope in Guaje Canyon (September 23, 2003) 8H 11 1 inch = 46 miles N 5: Photo ID; placement refers to approximate location of photo (August 12, 2003): Date photo was taken Unless treatments and / or recovery is occurring at a scale that can be delineated with 30 meter resolution specific correlations to Landsat NDVI are not possible. The classes depicted on the NDVI change map are based on a preliminary classification of the reflectance properties of the target area as recorded by a satellite sensor. The NDVI Change map is intended to support forest managers in their efforts to monitor vegetation recovery after a wildfire. This image map can be used to guide the assessment of vegetation conditions. This map may be modified by the field teams to represent actual ground conditions after proper field validation. Using this map for other than its intended purpose may yield inaccurate or misleading results. The USDA Forest Service uses the most current and complete data available during assessment of post-burn conditions. Geospatial data accuracy may vary. The USDA Forest Service reserves the right to correct, update, or modify geospatial inputs to this map without notification. For more information contact Jess Clark (jtclark@fs.fed.us) Greg Kuyumjian (gkuyumjian@fs.fed.us) USDA Forest Service Remote Sensing Application Center USDA Forest Service Santa Fe National Forest fsweb.rsac.fs.fed.us

27 Conclusions Inexpensive, repeatable, and objective Multiple customers Hydrologists, Soil Scientists, Foresters, etc. Visual tool for line officers and users RS provides information we can t see with our eyes RS is an element of analysis in conjunction with local knowledge and precipitation information

28 Questions For more information, please contact: Jess Clark Greg Kuyumjian