Abstract:

Lightning is a main natural fire source. Understanding the occurrence pattern of lightning fires in Daxing'anling is a base for the effective fire management. Based on the data of flashes and fires monitored during 2007—2009, the fire conditions when fires broke and lightning fire cases were studied to improve our understanding of the lightning fires in this region. The daily fire danger indexes for 11 weather stations in the study area were calculated with the method of Canadian fire weather index system to analysis the relationship among fires, flashes and fire danger. The results showed that there were 195 wildfires during 2007—2009, of which the 148 were forest fires. The fires mainly occurred in April, May and August and flashes occurred in a period from May to September, and mainly in June, July and August. The area with high flash density located in the northeast of the study region. Most of the lightning activity associated with rainfalls, but in drought years there were prone to dry thunderstorms, which may cause lightning fires. According to the distribution of wildfires and flashes in past 24 hours the lightning fires were identified, which accounted for 5.1% of the total wildfires. Therefore, the lightning fire is not the main fire resources in the region. Lightning fires mainly occurred in the day with high fire danger and frequent lightning activity without any effective rainfall.

Key words: Daxing'anling, lightning fires, flash, forest fires