Analysis of the Role of Land Cover Type on Peat Fire Potential Based on Ignition Moisture Content

Conversion of tropical peat swamp forests into cultivation areas, particularly oil palm plantations, often involves drainage, altering the natural hydrological regime. This study quantitatively analyzed the relationship between land cover type (Young Oil Palm, Mature Oil Palm, Old Oil Palm, and Forest) and peat maturity level in terms of peat fire potential. The analysis focused on key hydrophysical parameters. Maximum Moisture Content (MMC), Ignition Moisture Content (IMC), and daily Actual Evapotranspiration (AET). Field and laboratory analyses were conducted in West Kalimantan, Indonesia. The duration for peat to reach ignition conditions post-rain was calculated by dividing the allowable water column height loss (WCHL) (MMC - IMC) by the daily AET. It was found that AET was the only statistically significant parameter across all land cover types (LCT). The highest daily AET value was recorded in young oil palm plantations (9.61 mm/day), while the lowest was recorded in forest areas (4.42 mm/day). Consequently, peat in young oil palm plantations reached flammable conditions the fastest (28 days) post-rain. This was followed by old oil palm (44 days), mature oil palm (46 days), and Forest (50 days). These findings underscore the crucial role of high AET in young oil palm plantations as the dominant factor determining peat fire vulnerability, guiding effective water management and mitigation strategies. For fire mitigation, it is recommended that Ground Water Table (GWT) checks be conducted immediately at 2/3 of the peat’s post-rain drying duration. If GWT > 40 cm, immediate wetting should be performed until GWT reaches 40 cm.