Impact of wildfire on heat and moisture transfer in a seasonally thawed layer of soil studied by numerical simulation

Numerical simulation was applied to the processes of heat and moisture transfer and for ice-water phase transition in a season-thawed soil layer. Analysis was performed for consequences of natural wildfire on the soil temperature and the thawing depth as a function of water retention by soil for the condition of Siberian permafrost zone. Calculations demonstrate that the permafrost thawing depth increases due to burnouts in the top organic horizon. The quantitative indexes of natural wildfire impact depend on water retention properties of the upper organic horizon of soil.