至8月12日,参加内蒙古大兴安岭火场扑火的人员已超过8000人。当日,北部原始林区雷击火5大火场基本控制,但其中危险最大、火区面积最大的1号火场仍有3条火线在燃烧,其它4个火场的火点均得以全面和局部控制。 入夏以来,内蒙古北部林区持续高温干旱,干雷暴活动异常活跃。7月底以来,乌源、温河、珠中、伊利吉气等地区先后出现7处火点,均为雷击引发。 和以往的森林火灾不同,这次大兴安岭北部原始林区大火,是地表和地下同时燃烧,形成立体火。地下火是由一定厚度的“腐殖质土”被地表火引燃后形成的,很难有效扑打。对付这种“立体火”的有效办法,只能是开挖隔离带。 由于地形复杂,植被干燥,火场清理和加宽隔离带难度很大,异常活跃的干雷暴 By August 12, more than 8,000 people had joined the fire in the Daxinganling Fire Station in Inner Mongolia. On the same day, the basic forest fire control system for the five primary fireplaces in the northern primeval forest area was basically controlled. However, among the most dangerous fire areas, there were still three fire lines in the No. 1 fire area with the largest fire area burning while the fire points in the other four fire areas were fully and partially controlled. Since the beginning of summer, the northern part of Inner Mongolia has suffered from high temperature and drought in dry and thunderstorm activities. Since the end of July, there have been seven fire spots in Wuyuan, Wenhe, Zhuzhong and Yiliji areas, all of which are caused by lightning strikes. Different from previous forest fires, the fire in the virgin forest area in the northern part of Daxinganling Mountains burns at the same time on the surface and underground to form a three-dimensional fire. Underground fire is formed by a certain thickness of “humus soil” is ignited by the surface fire, it is difficult to effectively beat. An effective way to deal with this kind of “three-dimensional fire” can only be to excavate the isolation belt. Due to the complex topography, dry vegetation, clean-up of the fire field and widening of the isolation zone are very difficult and unusually dry thunderstorms