Analysis of In-Depth Spread of Smouldering Peatland Wildfire using Neutron Radiography and Multiphysics Computational Study

Smouldering is the driving mechanism in peat wildfires and the most persistent type of combustion phenomena. Peat fires require massive suppression efforts in terms of logistics (~tons of water) and duration (~months). In terms of fuel consumption, peat fire is one of the largest fires on earth, releasing massive ancient carbon that has not been participating in the global carbon cycle for milennia, thus contributing to the acceleration of climate change and further increasing the risk of peat wildfire across the globe. Challenges during firefighting are the relatively low ignition heat source in drought season and the subsurface spread due to the peat porosity that allows for oxygen diffusion into the ground. The structures of in-depth smouldering fronts have been studied by using limited thermocouple arrays and infrared camera, unable to see the actual in-depth propagation. The neutron radiography instrument detects visual footage based on the amount of Hydrogen atom. Our hypothesis is that the in-depth visual footage of a smouldering peat will vary according to the wet peat, dry peat, char, and ash fronts, as the density of Hydrogen in those fronts varies. Thus, allowing the visual investigation of in-depth smouldering spread which can validate multiphysics smouldering computational model. A better understanding of in-depth spread mechanisms allows for a better plan in preventing and mitigating this challenging and widespread phenomena of peat wildfires.