Fire Assessment

Once fires are extinguished, a combination of low resolution images (AVHRR) and higher-resolution images (SPOT, Landsat and Radar) can be used to assess the extent and impact of the fire. Radar has proved effective in monitoring and assessing the extent and severity of fire scars in the boreal forests (Kasischke et al., 1994), for quantifying biomass regeneration in tropical forests (Luckman et al., 1997) and for modeling ecosystem recovery in Mediterranean climates (Vietma et al., 1997). Low resolution visible and infrared sensors such as AVHRR have proved useful for automated fire mapping (Fernandes et al., 1997) and for evaluating the impact of fire on long-term land cover change (Ehrlich et al., 1997). Multi-resolution studies incorporating both AVHRR and Landsat images reveal the scale-related influences of analyzing post-fire vegetation regeneration (Steyaert et al., 1997).

Information related to new fire scars and vegetation succession within the scars can be used to update the baseline vegetation map used for fire prediction. Continued monitoring of the fire scars provides extensive information on land cover transitions involving changes in productivity and biodiversity, which in turn influence fire potential. Knowledge of the extent and intensity of fire scars provides important information for the rehabilitation of the burn areas.

Globally no reliable statistics about the exact location and annual areas burnt by forest fire are available. The information required and what can be achieved using Remote Sensing data are presented as Table 3.

Table 3. Forest Fire Assessment

Class of Information

Type of Information

a) alpha type

Fire : start and end dates, location, size and cause

b) beta type

Fuels biome classification and fuel loading forest inventory (number), age class, size class

c) gamma type

Fire characterisation (crown, surface etc.), fuel consumption and structural involvement (wildland urban interface)

d) delta type

Number of fires, areas burnt (by forest type), cause of fires (number)

e) epsilon type

Gas and aerosol emission data

f) eta type

Total expenditure of fire programme, total fire suppression costs and total direct losses of merchantable timber, structure losses

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