Peat fire occurrence

Abstract

In this chapter, various peat combustion properties, temporal and spatial peat fire occurrence in Kalimantan, and the peat fire index (PFI) for the early warning of peat fire were discussed. Firstly, tropical peat was sampled from Mega Rice Project (MRP) area in Central Kalimantan and analyzed in the laboratory. The flash point, ignition temperature and calorific value of tropical peat were measured by using a thermogravimetry and differential thermal analysis (TG-DTA) and a bomb calorimeter. The ignition probability of tropical peat was estimated by using literature values. In fields of the study area, peat ignition test, surface temperature measurement of actual burning peat and peat fire propagation measurement were carried out to identify actual peat fire conditions. Secondly, recent seasonal and special fire occurrence trends in Kalimantan were discussed using analysis results of MODIS hotspots data (fires) and precipitation data (the 10 years data, from 2002 to 2011). The two provinces of Central and West Kalimantan have the different severe fire periods. The fire season in West Kalimantan started in early August and lasted until early September. On the other hand, the fire season in Central Kalimantan started in middle August and continued until early November. Finally, peat fire index (PFI) derived from monthly and daily rainfall data was proposed to estimate peat fire conditions. The PFI has a linear relationship to the annual lowest groundwater level in peatland with the coefficient of determination R2=0.84, and to the total number of hotspots observed byMODIS during the dry season from June to November in Central Kalimantan with R2=0.74. The PFI was found to be useful for the early warning of peat fire in tropical peatlands. The depth of combustible peat layer increased linearly with lowering of groundwater level in tropical peatlands.