A wildfire is an unplanned, unwanted wild land fire (including unauthorized human-caused fires). Vegetation fires are caused by slash/burn land clearing, clearing of plantations following logging operations, and by natural events such as lightning or extreme drought. The dry seasons provide peak conditions for wildfires to occur, and it is during this time that they are most prevalent and present a transboundary problem when prevailing winds disperse the smoke across borders to other countries. Wildland fires are usually signaled by dense smoke that fills the area for miles around.
Characteristics/Measurements:
There are three different classes of wildland fires:
1. A surface fire is the most common type and burns along the floor of a forest, moving slowly and killing or damaging trees.
2. A ground fire is usually started by lightning and burns on or below the forest floor.
3. Crown fires spread rapidly by wind and move quickly by jumping along the tree tops.
Impacts/Causes of Injury and Damage:
Destruction of vegetated, and eventually inhabited areas and construction sites, can potentially lead to large areas with ecological and economical losses. A major wildland fire can leave a large degree of scorched and barren land. These areas may not return to pre-fire conditions for decades. If the wildland destroys the ground cover, then erosion becomes one of several potential problems.
Smoke and other emissions contain pollutants that can cause significant health problems. The short-term effects include destruction of timber, forage, wildlife habitats, scenic vistas, and watersheds. The long-term effects can include reduced access to recreational areas; destruction of community infrastructure and cultural and economic resources.
Emergency Action/Control Techniques:
Bushfires are usually fought by numerous trained volunteers and a core team of professional firefighters with vehicle-mounted equipment (in accessible terrain). Observation is often provided by light aircraft and helicopters. Water-bombing is also provided by helicopters with buckets which lift water from dams, lakes or swimming pools. They are effective in stopping spot fires ignited by windborne firebrands, sometimes kilometres ahead of the main fire-front. This greatly assists and contributes to the safety of firefighting crews. In large bushfires, bulldozers and graders are used to create emergency firebreaks ahead of firefronts. Back-burning from firebreaks is frequently effective in slowing or stopping the spread of fire.
Mitigation includes any activities that prevent an emergency, reduce the chances of an emergency occuring, or lessen the damaging effects of unavoidable emergencies. Investing in preventive mitigation steps now, such as installing a spark arrestor on your chimney, cleaning the roof surfaces and gutters regularly and using only fire-resistant materials on the exterior of your home, will help reduce the impact of wildland fires in the future. For more information on mitigation, contact your local emergency management office.
Source:
IFFN: Recent Trends of Forest Fires in Central Asia and Opportunities for Regional Cooperation in Forest Fire Management (http://www.fire.uni-freiburg.de/iffn/iffn_31/16b-IFFN-31-Central-Asia-2.pdf)
USGS: Wildfire Hazards – A National Threat (https://pubs.usgs.gov/fs/2006/3015/2006-3015.pdf)
EMA: Hazards, Disasters and your Community (http://www.emergencyvolunteering.com.au/docs/Hazards_Disasters_and_your_Community.pdf)
Further Information: Emergency Management Australia (https://www.ag.gov.au/EmergencyManagement/Emergency-Management-Australia/Pages/default.aspx)
