Assessing rainfall pattern, groundwater level, and peat hydraulic conductivity for effective peat prevention measure

Abstract

Severe drought and less precipitation during a prolonged dry season and El-Nino events has been observed as a main trigger of the decrease of groundwater level leads to the dryness of the degraded peat and exacerbates burning conditions. To get a better understanding of this issue, we studied fire conditions in a portion of the ex-Mega Rice Project (MRP) area, Central Kalimantan. Here, we examine fire season and hydrology factors affecting peat fires by using Terra/Aqua MODIS hotspots dataset and groundwater level data from 300 dipwells and 15 staff gauges established in the MRP area. We use the Interpolation Data Weighting (IDW) to explain the fire risk in the area based on its hydraulic conductivity. Our results clearly show that even the moderate to high rainfall intensity is not enough to rewet the dry-degraded peat and thus to leave them in dry condition. Here, we highlight the importance of considering the rainfall pattern of previous successive dry and rainy season for fire risk assessment. Most of the fires occurred in the area between 1.1×10-6 and 2.1×10-6 cm/s hydraulic conductivity and below -10 cm groundwater level, sharply pointing out the importance to keep degraded peat in wet condition for fire prevention.