Forest Fire Control Division

2.1 Type, Duration and Occurrence

Forest fires in Thailand annually occur during the dry season from December to May with their peak in February-March. Fires, Mostly classified as surface fires, mainly take place in; Mixed Deciduous Forest, Dry Dipterocarp Forest, and Forest Plantations, and to some extent in Dry Evergreen Forest, Hill Evergreen Forest or event in some parts of the Tropical Rain Forest. In certain extremely dry sites, double burning in one season is common. These surface fires consume surface litter, other loose debris on the forest floor and small vegetation.

Table 1. Area burnt in each type of forests in 2000

Although other types of fire are not typical to the forest of these region, in recent years a notable number of crown fires took place in Pine Plantations. Also ground fires occurred in swamp forest. Such incidents of swamp forest fires are clear indication that climatic changes already have occurred in Thailand.

2.2 Duration

Forest fires in Thailand annually occur during the dry season from December to May with their peak in February-March. (Figure1)

Figure 1. Fire duration (data average from 1998-2003)

During the day, most fire activities concentrate from noon to 4 pm.

Figure 2. Fire frequency round the clock.

2.3 Fuel types and loads

Since fires mainly taking place in seasonal forests, therefore it largely depend on dead fuel accumulated on forest floor during dry season especially dry litter and dead grass. However, undergrowth and dry twig also contribute to loads of fuel. Fuel load in Dry Dipterocarp is est. 4,000-5,000 kg/ha., while Mixed Deciduous contains 5,000 kg/ha. (Table 2)

Table 2. Fuel types and loads

Table 3. Fire behaviors

2.4 Fire behaviors

The common surface fires in Dry Dipterocarp as well as Mixed Deciduous Forests are quite moderate in intensities. Rate of fire spread approximately 2-4 metre/minute in fair condition. However rate of spread increases shapely upon the increase of slope. While in grasslands and dry-out bamboo forests, fires behave in a much more severe manner, flame length can reach 15-20 metres in steep slope or strong wind. Some data from experimental fires were shown in Table 3.

Table 3. Fire behaviors

[Type and Duration] [Causes] [Annual burnt areas] [Fire Impacts]

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Department All Rights Reserved.

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E-mail:: fire@dnp.go.th, forestfire_th@yahoo.com