7th Workshop on Forest Fire Management - EARSeL, European ...

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IV - BURNED LAND MAPPING, FIRE SEVERITY DETERMINATION, AND VEGETATION RECOVERY ASSESSMENT
burned areas by means of satellite data has been traditionally carried out
by the Advanced Very High Resolution Radiometer (AVHRR) (Kaufman et al.,
1990; Chuvieco et al., 2008). However, the MODIS sensor is opening a new
era in the remote sensing of burned areas (Justice et al., 2002; Roy et al.,
2005). MODIS is a sensor housed on Terra and Aqua NASA satellites with
more than 30 narrow bands at wavelengths from the visible to the thermal
infrared and at variable spatial resolutions (250 to 1000m).
Among the different methods for burn mapping by means of reflectance
satellite data, the use of spectral indices is one of the most widespread. In
addition to the latter, several studies have showed the utility of active fire
detections. In this case, fire thermal energy, as measured by mid-infrared
channels, is used to identify active fires and scar mapping is developed
based for example in the total number of active fires (Pozo et al., 1997).
Although the temporal and spatial patterns of biomass burning cannot be
estimated reliably from active fire data (Roy et al., 2005), this difficulty
can be solved through the combination of active fire information together
with spectral indices, as proposed in this work.
The work presented here assesses the estimation and mapping of burned
areas in Colombia in 2004 using a method that integrates a spectral index
with active fire data, both as derived from MODIS data. In a second step,
the resulting 1km spatial resolution MODIS-based scar map was validated
using two satellite-derived burn area products.
2 - Study area and materials
The approach is applied here to H10V08 tile in Colombia (figure 1) where
hundreds to thousands of wildfires occurred during the winter months
(January to March) each year. The area covered by the MODIS image is 1200
by 1200km size. First analyses were carried out over a sub-scene of 300 by
300km size (figure 1).
Three types of data were used for this work: (i) MCD43B4-2004025 (MODIS
Terra + Aqua Nadir BRDF-adjusted reflectance 16-day L3 Global 1km; 25 th
January to 9 th February 2004), (ii) MOD14A2 and MYD14A2 (MODIS Terra
and Aqua Thermal Anomalies 1km; 1 st January to 9 th February 2004) and
(iii) ancillary maps and information. For validation purposes, two datasets
were used: (i) L3JRC-2004 (Global, Daily, SPOT VGT-derived Burned Area
Product) and (ii) MCD45A1-2005001 (MODIS Terra + Aqua Burned Area
Monthly L3 Global 500m; 1 st to 31 st January 2004).