Backgrounders

Initial Attack Crews: Initial attack fire fighters are usually the first crews on the scene of a new fire. The crews generally respond to small fires and are the key reason we are able to contain more than 94 percent of British Columbia's fires at a size of less than four hectares.

With specialized training, IA crew members can be quickly deployed via helicopter to parachute drop.

Unit Crews: Each year, a small percentage of fires grow to a significant size, which require additional fire fighters and resources. Twenty-member unit crews were developed to serve as a highly trained and coordinated fire fighting force for these larger fires. Each crew is made up of one crew leader, four squad bosses and fifteen crew members. The 20-person unit may also be broken into smaller groups depending on the nature of the fire activity.

Unit crews are often called sustained action crews because of their specialized skills for fighting larger blazes as well as their ability to be self-sufficient on a fire for up to 72 hours.

Weather conditions are one of the most critical factors in fire behaviour. The forest service maintains a network of weather stations across the province that provide key information on humidity levels, wind speed, direction and rainfall.

Lightning is one of the major causes of wildfires. On average, about 50 percent of all forest fires in B.C. are caused by lightning. The Canadian Lightning Detection Network, provided by Environment Canada, consists of a network of lightning locators that provide complete coverage of the province. This network can detect more than 90% of all lightning strikes occurring in B.C.

To collect the data, the lightning locators continuously detect and record all cloud-to-ground lightning strikes as they occur within or near British Columbia. Lightning data is triangulated and the approximate location of the lightning strike is determined. After triangulation, the data is sent to a large main-frame computer. All of this takes about 60 milliseconds. The information is then sent to Protection.

Forest Service personnel create maps that show the location, day, and time for any lightning strike, and these maps let crews check lightning hot spots for new wildfires. Information from this system is also used by fire managers to route and schedule air patrols and to determine standby and resource allocation.

Lightning can strike almost anywhere, even as far as 15 kilometres away from a storm cell, so ground conditions around the strike may not be affected by rain. Dry lightning can also occur under the storm cell when the base of the cloud is so high that the rain evaporates before reaching the ground. Dry lightning is a potent ignition source because if the fuels are dry there will not be enough moisture to interfere with ignition or fire spread.