🌋3.1.5.6 - Fires in Nature Flashcards
What is a wildfire?
A bushfire or rural fire which is uncontrollable and spreading
What are the three things needed for fires to burn?
Heat, Fuel and Oxygen
What can sources of fuel include?
Trees Logs Dry Grass Petrol Aerosols Leaves
What can sources of heat include?
Cigarette ends Matches Barbecues The sun Electrical storms Broken glass Arson
How can the seasons affect the likelihood of wildfires?
The drier and windier the season, the more likely the wildfire
What is the most common cause of wildfire?
Arson
Which factors can worsen wildfires?
Dry vegetation
Ladder fuels
Hilly areas
Homes with wooden/timber cladding
Flammable fertilisers
How can wildfires be prevented?
Remove ladder fuels
Control of vegetation
Removal of fuel sources
Burn off crops after harvest
What phenomenon can make conditions warmer and drier?
El Nino and the Indian Ocean Dipole
How does vegetation type affect wildfires?
Water stroing plants eg Cacti are much harder to burn
However Eucalyptus use the nutrients released from ash and the additional light from surrounding vegetation being burned, so promote wildfire
How can wildfires be mitigated against?
In countries such as Australia and the US, which are prone to fires, organisations produce advice for residents and some states such as Colorado provide residents with a set of guidelines
What are some of the guidelines set in Colorado?
Reduce fuels around the home
Mow grasses and weeds often, to shorter than 6 inches
Use fire resistant materials in the house
Dispose of any excess accumulation of logs
What is the most popular wildfire education campaign in the US?
Smokey Bear
What are the five rules in the Smokey Bear song?
Only you can prevent wildfires
Always be careful with fire
Never play with matches or lighters
Always watch your campfire
Make sure your campfire is out before leaving it
How effective has Smokey Bear been?
It was launched in 1944 and has since been popular with children and adults, teaching the effect of wildfire on the environment. The success has largely been down to the character.
What do NEPA do in the US?
The National Fire Protection Agency runs fire community preparedness days annually to help reduce fuels and educate communities
How can wildfires be detected?
Using traditional manned lookout towers, which can be unreliable and require 24 hour surveillance, or more recently, computer based video analysis which can automatically produce an alert
What does the law state in California?
The residents must clear out all flammable materials such as bush or vegetation around 100ft of the property to create defensible space
What does the law state in Scotland?
The any open fires must be kept under control and must not be lit in prolonged dry periods in areas such as grasslands or forests
What’s the 2 year project called that’s been launched in Europe?
IGNIS (2016)
What’s IGNIS aiming to do?
Improve the fire and rescue response by bringing together knowledge and expertise
Example of a group involved in IGNIS
Northumberland Fire and Rescue Service
Natural Causes of Wildfire
Lightning
Lava
Humans Causes of Wildfire
Falling power lines
Campfires
Fireworks
Arson
Agricultural burning (controlled fires)
Why does the El Nino Effect cause more intense burning?
As it’s drier and hotter
Why does drought favour more intense wildfires?
Low levels of retained water in plants- burns more quickly
Ladder Fuel
Live or dead vegetation allowing a fire to climb from the forest floor to the tree canopy, meaning the fire is more influenced by winds
Preparedness: 2 Countries Techniques on Educating
America- Smokey Bear
Australia- TV Adverts
Preparedness: What are computer simulations used to do?
Model the fires track
Preparedness: 2 Ways of Spotting Wildfires
Aircraft survey large areas
Satellites provide low resolution images
What do Australia have on weather forecasts?
Fire Danger Ratings
Prevention: How does managing vegetation work?
Controlled burning creates fire breaks, stopping a fire during a disaster
Prevention: 3 ways to manage the built environment
Increase gaps between homes
Install fire beaters in areas where barbecues and campfires are common so fire doesn’t rapidly spread
Use more fire resistant burning methods
Why’s it important to replant trees after a wildfire?
To avoid flash floods and mudslides on unprotected slopes
3 Aspects to Conditions needed for Wildfires
Vegetation Type
Climate / Weather
Fire Behaviour
Oxygen Key Points
Strong winds = more oxygen so fire can spread more quickly
Difference between Ground fire, Surface fire, and Crown fire
Ground- slow, smouldering, no flame, little smoke
Surface- leaf litter, low lying vegetation burns, can be low or high intensity
Crown- moves rapidly through canopy, most intense and fastest moving
Heat transfer
. Radiation is the transfer of fire to an adjacent object by causing it to combust without touching it.
. Convection is in an upward direction
What 3 things effect wildfires behaviour
Fuel, topography, weather
