Supplementary material for Simulation of fire behavior in combustible material from dry tropical forest of the Caatinga biome
Description
The combustible material collections were carried out in areas of preserved caatinga, as they present a greater amount of plant material and because they are more susceptible to forest fires (Fig S1). In each area, three plots measuring 20 m x 20 m (400 m²) were randomly installed and then georeferenced with a GPS (Fig S2). The collection of combustible material, in each plot, was launched a template with dimensions of 1.0 m x 1.0 m at random, and this procedure was performed 3 times in the areas, establishing an interval of 100 m between each plot. The combustible material collections were carried out in September 2018, the beginning of the dry season in the region, with the combustible material being dry to facilitate the collection and handling of this material for subsequent monitoring of the burnings. The removal of vegetation was carried out using a machete and pruning shears to facilitate the removal of all superficial combustible material up to 1.8 m in height that was inside the template (Fig. S3). The material collected in each plot was placed in properly labeled nylon bags. To obtain the ash content, initially, 1.6 g of each sample were weighed in each crucible on an analytical balance of 0.01 g precision. Then, it was placed in an oven at 105º C, for 24 hours. After this procedure, the same crucibles with material were placed in a muffle furnace at a temperature of 600º C for a period of 6h40min. The crucibles were removed, placing them in a desiccator for approximately one hour, until stabilization at room temperature (Fig. S5). It is observed that the values of organic matter, ash content and calorific power, on average, are important parameters in estimating the flammability of vegetables. In organic matter, there was no significant difference between combustible materials in the regions evaluated. Organic matter values ranged from 94.86 to 89.52%. Regarding the ash content (Table S1), it was found that there was no difference between the values that ranged from 10.49% to 6.25%. The low ash content in the material evaluated in this study justifies that all combustible materials in geographic regions are suitable for energy generation, that is, the lower the ash content value, the greater the burning power. In the calorific value (Table. S1), there was no difference in the values of the materials evaluated. The values obtained were high and ranged from 17877.86 kJ kg-1 to 21663.55 kJ kg-1, which proves that, in case of forest fires in these areas, the energy that maintains the combustion reaction is high, which favors greater intensity Of fire. The low moisture content of the fuel material directly influenced the increase in calorific value. This is related to the low energy requirement for the evaporation of combustion gases in the form of water vapor.