Презинтация на тему "Природные катаклизмы.Пожар."

Wildfire

What is a wildfire?

A wildfire also known as a wildland fire, vegetation fire or hill fire is an uncontrolled fire often occurring in wildland areas, but which can also consume houses or agricultural resources. Wildfires often begin unnoticed, but they spread quickly igniting brush, trees and homes.

What causes a wildfire?

Common causes of wildfires include lightning, human carelessness, arson, volcano eruption, and pyroclastic cloud from active volcano. Heat waves, droughts, and cyclical climate changes can also have a dramatic effect on the risk of wildfires. Although, more than four out of every five wildfires are caused by people.

Where can wildfires occur?

Wildfires can occur anywhere, but are common in the forested areas of the United States and Canada. Fires are particularly prevalent in the summer and fall, and during droughts when fallen branches, leaves, and other material can dry out and become highly flammable. Wildfires are also common in grasslands and scrublands.

What is a fire tornado?

A fire tornado or fire whirl is just a tornado made of fire. It happens when certain conditions (depending on air temperature and currents), acquires a vertical vorticity and forms a whirl, or a tornado-like effect. Fire tornadoes may be whirlwinds separated from the flames, either within the burn area or outside it. A fire tornado can make fires more dangerous.

How do firefighters put out the wildfires?

Firefighters use a tool known as a pulaski. Its a combination of an ax and hoe used to dig a fireline. A fireline is a strip of land from which all brush and debris have been cleared to rob a wildfire of its fuel.

How do firefighters put out the wildfires?

Firefighters also use hotshots and smoke jumpers to clear a large path in a big circle around the fire so the blaze is contained in a ring of dirt. When the fire reaches this area, it runs out of fuel and starves to death. If the fire is too large, however, planes and helicopters fly overhead, dropping water and special chemicals that

smother the flames. This pink,

fire-retardant chemical is called

sky jell-o.

Wildfire Safety Tips

DURING A WILDFIRE: If you’re advised to evacuate then do so immediately. Wear protective clothing and lock your home. Tell someone you left and where you are going. Choose a safe route away from fire hazards. Watch for changes in the speed and direction of fire and smoke.

AFTER A WILDFIRE: Stay away from wildfire areas until it is safe.