Influence of moisture and inorganic contents on smouldering spread rates in the lateral and in-depth directions

Abstract

Peat, an organic soil resulting from the accumulation of dead organic matter, is a material that can sustain smouldering fires. Annually, peat fires contribute significantly to wildfire emissions, releasing large quantities of stored organic carbon contributing to positive climate feedback and can be blow into nearby cities causing significant adverse health effects (Hinwood & Rodriguez 2005). This paper, for the first time systematically studies the influence of moisture and inorganic content, two key soil properties, on the horizontal and indepth spread rate simultaneously. A negative linear relationship was found between spread rate and increasing moisture and inorganic contents. While moisture content apeared to increase the indepth spread rate, decreaseing the inorganic content reduces the spread rate, both tendencies are consistent with the results found in literature. These finding greatly improves the understanding of the influence of soil properties on smouldering spread in thin layers.