wildfires revision guide
TRANSCRIPT
Wildfires Revision Help
Distribution of Wildfires Areas where it is hot and dry.A belt across the Sahel in Africa California( eastern USA)Parts of Australia
Causes of WildfiresNatural causes
• Lightning• Spontaneous heating ( material is
heated to a point that a spark is not needed)due to large amounts of plant build up.
• Volcanic eruptions• Spread quickly in hot dry weather ,
fallen branches and leaves dry and catch fire easily especially when there are strong winds e.g. Santa Ana winds (140 km per hour).
• South facing slopes -sun dries out the vegetation increasing risk of fires
• Steep slopes means fires spread quickly
Human Causes• Accidents children playing
with matches, camp fires cigarettes
• Broken bottles act as magnifying glass
• Slash and burn• Arson • Sparks from train wheels ,
machinery military training• barbeques
Causes of wildfires in New South Wales Australia
• Arson 37%• Farming 10%• Campfires 13%• Lightning 23%• Other 16%• Trains 1%
Effects of Californian WildfiresPrimary effects
• 9 people killed • 85 injured• 640,000 people had to
evacuate • 1,800 homes
destroyed($1.6billion damage)
• 200,000 hectares of grassland destroyed
• Water air pollution( 3 times normal level)
• Breathing problems for people
Secondary effects
• Loss of jobs and income for farm workers
• Loss of habitats for animals to survive
• Loss of income from businesses
Reducing the effects of wildfires
• Prevention educate people ( Smokey Bear campaign), how to reduce the risks of sparkes from vehicles, and how to dispose of cigarettes.
• Making homes as fire proof as possible .• GIS to forecast • Fire lines to prevent breaks
Responses to wildfires
• Fire fighters put out fires with water and gel• Fire resistant chemicals are released from aircrafts onto
wildlife • Areas ahead of fires are sprayed to stop it spreading• Helicopters are fitted with large buckets filled up with water
from lakes or the sea • Fire lines are created, without a supply of fuel the wildfire will
eventually burn out• Backfires is set alight to remove the fuel in the direction the
fire is spreading
Will there be more wildfires in the future
yes• Due to global warming
oceans have increased by 0.5C
• Last 30 years more tropical storms with wind speeds of 200km/hr
• Number of tropical storms has increases in last 100 years
no• We do not have evidence to
support this
• Satellite technology has only been used since 1960.
• There appears to be a natural cycle of variations in the number of hurricanes.
• 1995-2005 average wind speeds of storms increased by 15% and the length increased by 60%
• More tropical storms reaching category 4 and 5
Cost of damage is increasing
• More people are affluent ( well off) and choose to live or spend their holidays near the coast ..... The value of property has increased....... There is more infrastructure ( due to the increase in population)..... This has meant there is greater potential damage and the economic costs of hurricanes are increasing
More wildfires to come?
yes By 2007 the length of wildfire
season in USA had increased by 78 days
• Average size of wildfires and total area destroyed has increased
• Global warming • Increased temperatures
no• Part of a natural cycle
Cost of damage is increasing
• Cost of the damage of wildfires is increasing (MEDC).
• In USA over 10 million homes have been built in wildland-urban interface. More people are more affluent and choose to live or have a second home in remote rural areas