NUMERICAL ANALYSIS OF TRANSIENT SOIL TEMPERATURE VARIATION DURING WILDFIRES

In this study, transient behavior of soil temperature during large forest fires is analyzed using the Comsol© software package. The increase in soil temperature during large wildfires can be very critical, especially when oil or gas pipelines have been laid at a certain depth in the soil in or near forests. During forest fires, the temperature of the soil surface can reach extreme levels that penetrate deep into the ground if the fire is not extinguished within a short period of time. This increase in temperature on the soil surface can lead to extremely dangerous situations if the laying depth of the pipeline is not sufficient, since the heat conducted through the soil causes the surface temperature of the pipeline and therefore that of the fluid inside to also reach very high values. This can lead to a sudden rupture of the pipeline and ultimately lead to catastrophic consequences. Although the present study is conservative due to the assumptions made in structuring the numerical model, it is believed to provide invaluable information about the considerations in selecting gas pipeline locations and pipeline laying depths, while also taking into account extreme temperatures due to wildfires, seismic impacts and traffic loads. Future research could include extensive study on the energy content of different species of forest trees, considering their time-dependent heat release rates (HRR) during a forest fire, as well as experimental work if a realistic setup could be designed.