Fighting against fires
Fighting against fires
As the winter weather gets colder and drier, forest fires occur more frequently. The dry wind lowers moisture of fallen leaves; hence, dry leaves or grass are quick to catch fires even by cigarette ashes.
Usually, the leaves start to burn yellow at 150~180℃, carbonized at 200℃ and spark into flame at over 400℃. Forest fires spread faster with the wind under 5m/second. It is similar to blowing or fanning the flame when making fires.
Fires in pine or shrub forests are more intensive. Fires in those forests create a big flame caused by high temperature ascending the air. When the fire becomes intensive, the flame shots up with the whirlwind by air, rising up. The flame could reach to 100m in height. California forest fire last year, causing $2 billion damage and forest fires in Gang-won province of Korea in year 2000 are the cases.
The fires caused by updraft sparks flames. Flying sparks, such as pinecones, branch and bark catch fires and fly to the head direction of the fire movement. There were flying sparks, flying 1.5~2km high during the Donghae-an fire in 2002.
Extensive forest fires are hard to control and cause severe damage. There are about 3.4ton of soil loss per ha in burned areas. It takes at least 3-4 years to recover from the soil loss.
Once the forests are damaged by fires, it takes about 40 years of restoration and 50 years of ecosystem recovery. According to the research by University of Sao Paulo, in Amazon, the temperature is dropping by 3℃ annually due to the black dirt or dust from forest fires.
Consequently, countries worldwide are developing high technologies for forest fire prevention. One of widespread tools is using satellite known as GPS. GPS enables early detection of forest fires.
The U.S. National Oceanic and Atmospheric Administration (NOAA) developed Wildfire Automated Biomass Burning Algorithm system in cooperation with Space Science and Engineering Center at UW-Madison, using GOES for tracking the movement of fires. The system provides real time imagery and data.
Korea also has developed forest fire watch satellite system, using BIRD satellite of Germany. This system detects forest fires, sensing infrared rays from the fires. BIRD can track 2mX2m size of forest fires with its ray detection camera.
Robot technology is also broadly used. One of the recent developments is a remote control aviation robot which has helicopter or air-moving body, and it detects the progress of fires.
There are two ways of recovering damaged areas from forest fires: artificial regeneration and natural regeneration.
An artificial regeneration method is to replant trees in contour lines, cutting the burned parts off. This method could prevent landslides and water pollution caused from soil disturbance. Also, it provides wildlife with habitat.
On the other hand, burned areas with fertile soil are likely to take natural regenerating process. In mixed forests, pine forest with young oak trees, stumps of burned trees begin to develop new shoot.
To achieve complete recovery, both artificial regeneration and natural regeneration methods will be applied after the environmental research by experts.
Major causes for forest fires in Korea are by human activities: accidental fires in mountains (42%) and agricultural burns (18%).
We always need to watch out fires in and outside home.
(Lee, Myung-bo, Director of Forest Fire)