5. FIRE EFFECTS ASSESSMENT 
One of the main problems affecting fire 
management is the lack of appropriate statistics 
on burned land. Even the countries more 
severely affected by this problem do not have 
proper data on fire incidence, as most of the 
times fires are not mapped and only general 
Statistics are available. On the other hand, data 
are not available until several weeks (or even 
months) after the fire event. As a result, 
vegetation recovery is not assessed, and a lack 
of regrowth may constitute a severe soil 
erosion hazard (Isaacson et al., 1982). 
Moreover, these field inventories are often 
very general. Usually, only the scorched 
perimeter is drawn, but no information about 
the species affected or severity of damage is 
provided. Furthermore, studies on vegetation 
succession after fire are seldom done. 
The growing interest in global effects of fire 
processes demands a quantitative evaluation of 
the spatial and temporal distribution of fire 
patterns (Levine, 1991): a wide range of 
disciplines, such as fire ecology, fire 
management, atmospheric chemistry and 
forestry, will benefit from burned land maps at 
global and local scale. 
Most of the fire mapping projects have been 
based on channel 3 data. However, as it was 
stated before, this channel presents several 
difficulties for fire detection and, therefore, for 
burned land mapping. Another approach for 
burned land evaluation is based in measuring 
the consequences of the fire, rather than 
detecting the fire itself, by multitemporal 
comparison of vegetation indices acquired from 
before and after the fire. 
Several studies have shown that spectral 
characteristics of burned land contrast sharply 
with the response of healthy vegetation. Burned 
land shows a severe decrease in near infrared 
reflectance, as a consequence of leaf 
deterioration, and an increase in red reflectance 
because of the lack of pigments' absorption 
48 
(Tanaka et al., 1983). Therefore, the NDVI 
values of burned vegetation are much lower 
than those of healthy plants, and multitemporal 
analysis should clearly portray fire alteration. 
Some studies have proven this hypothesis, 
obtaining adequate results from both high and 
low resolution sensors (Kasischke et al., 1993; 
Martin et al., 1994; Pereira et al., 1994). 
7. FUTURE PROSPECTS 
Future availability of better spatial, spectral and 
temporal resolution sensors will overcome 
some of the present limitations of satellite data 
for fire management. MODIS data will 
increase spatial and spectral detail currently 
provided by the AVHRR sensor for both short- 
term fire danger estimation and fire mapping. 
This sensor, along with the Meteosat Second 
Generation, will also very valuable for 
operational fire detection, even in European 
countries. The growing tendency toward the 
combined analysis of GIS and Remote Sensing 
data will benefit fire risk and fire effects 
assessment as well. 
8. REFERENCES 
Belward, A.S, 1991. Remote sensing for 
vegetation monitoring on regional and global 
scales. In: Remote Sensing and Geographical 
Information Systems for Resource Management 
in Developing countries, (A.S.Belward, and 
C.R.Valenzuela, editors), Kluwer Academic 
Publishers, Dordrecht, pp. 169-187. 
Burgan, R.E. and Rothermel, R.C., 1984. 
BEHAVE: Fire Behaviour Prediction and Fuel 
Modeling System. Fuel Subsystem, USDA 
Forest Service, Ogden, Utah. 
Burgan, R.E. and Shasby, M.B., 1984. 
Mapping broad-area fire potential from digital 
fuel, terrain and weather data. Journal of 
Forestry, Vol. 82, pp. 228-231. 
Chou, Y.H. 1992. Management of wildfires 
with a Geographical Information System. 
International Journal of Geographic 
Information Systems, Vol. 6, pp. 123-40. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B6. Vienna 1996 
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