✅HAZARDS 3.1.5.6 - Fires in Nature

Question 1

What is a wildfire?

Answer 1

A bushfire or rural fire which is uncontrollable and spreading

Question 2

What are the three things needed for fires to burn?

Answer 2

Heat, Fuel and Oxygen

Question 3

What can sources of fuel include?

Answer 3

Trees
Logs
Dry Grass
Petrol
Aerosols
Leaves

Question 4

What can sources of heat include?

Answer 4

Cigarette ends
Matches
Barbecues
The sun
Electrical storms
Broken glass
Arson

Question 5

How can the seasons affect the likelihood of wildfires?

Answer 5

The drier and windier the season, the more likely the wildfire

Question 6

What is the most common cause of wildfire?

Answer 6

Arson

Question 7

Which factors can worsen wildfires?

Answer 7

Dry vegetation
Ladder fuels
Hilly areas
Homes with wooden/timber cladding
Flammable fertilisers

Question 8

How can wildfires be prevented?

Answer 8

Remove ladder fuels
Control of vegetation
Natural 'breaks' or borders
Removal of fuel sources
Burn off crops after harvest

Question 9

What phenomenon can make conditions warmer and drier?

Answer 9

El Nino and the Indian Ocean Dipole

Question 10

What is El Nino?

Answer 10

A climate cycle in the Pacific Ocean with a global impact on weather

Question 11

How does vegetation type affect wildfires?

Answer 11

Water strong plants eg Cacti are much harder to burn while Eucalyptus use the nutrients released from ash and the additional light from surrounding vegetation being burned, so promote wildfire

Question 12

How can wildfires be mitigated against?

Answer 12

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

Question 13

What are some of the guidelines set in Colorado?

Answer 13

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

Question 14

What is the most popular wildfire education campaign in the US?

Answer 14

Smokey Bear

Question 15

What are the five rules in the Smokey Bear song?

Answer 15

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

Question 16

How effective has Smokey Bear been?

Answer 16

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.

Question 17

What do NFPA do in the US?

Answer 17

The National Fire Protection Agency runs fire community preparedness days annually to help reduce fuels and educate communities

Question 18

How can wildfires be detected?

Answer 18

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

Question 19

What does the law state in California?

Answer 19

The residents must clear out all flammable materials such as bush or vegetation around 100ft of the property to create defensible space

Question 20

What does the law state in Scotland?

Answer 20

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

Question 21

Crown fires

Answer 21

Burn up trees the entire length, most intense and dangerous
Up to 1,100°C

Question 22

Surface Fires

Answer 22

Burn only surface litter
Easiest to put out
900°C

Question 23

Ground Fires

Answer 23

AKA underground or subsurface fires
occur in deep accumulations of humus, peat, etc.
Very slow, hard to put out
Can smoulder underground in winter and emerge in spring
540°C

Question 24

How vegetation affects wildfires

Answer 24

Denser, drier, taller = more flammable
Some vegetation has flammable sap like eucalyptus and acacia

Question 25

How climate affects wildfires

Answer 25

Dry (under 7% humidity) and windy for more fires
Temporal Variation, like El Niño (wet S American, dry SE Asian, warmer North America as jet streams head south) can make conditions more favourable

Question 26

How topography effects wildfires

Answer 26

Air from mountains gets compressed and warmed, so less humid, dries out vegetation.
Fires travel faster upwards than forwards, so hills = faster travel

Question 27

Australian Wildfires Dec 2019- Jan 2020

Answer 27

Positive Indian Ocean Dipole caused temps to rise to 41°C in Australia

Question 28

Positive effects of wildfires

Answer 28

Some plants are adapted against fires, pyrophytic plants, like Baobab Tree with resistant bark
Clearing vegetation makes way for new grass, breaks down vegetation into nutrients for soil

Question 29

How fires impact soil and land

Answer 29

Can damage soil structure and nutrient content
Like in Georgia, US, 2017, 55000m^2 damaged
LT, less evapotranspiration, less rain

Question 30

How wildfires impact health

Answer 30

Breathing problems
in SE Asia, 1997/8 fires caused 60 000 to need hospital treatment for this

Question 31

Example of wildfires emergency response

Answer 31

Greece 2007, 9000 firefighters used to cover 200,000 hectares of devastated land