Hazards BK 6 - Fires in Nature

Question 1

when do fires occur

Answer 1

when oxygen combines with carbon, hydrogen and other organic material, producing flame, heat and light

Question 2

what percentage of fires actually accounts for the 95% of areas burnt

Answer 2

3%

Question 3

what are crown fires

Answer 3

fires that pass from one tree to another

Question 4

what’s a surface fire

Answer 4

where a wall of fire along what’s called either a combustion front or flaming combustion

Question 5

what’s a ground fire

Answer 5

one that moves slowly at ground level through what can be known as glowing combustion

Question 6

how hot can ground temperatures get during surface fires

Answer 6

over 1000 degrees

Question 7

what four things can impact the nature of the fire

Answer 7

plants involved
strength of winds
topography of the area
behaviour of the fire

Question 8

what’s a retardant

Answer 8

chemicals sprayed on to fires in order to slow them down

Question 9

define pyrophytic vegetation

Answer 9

phrophytes are plants adapted to tolerate fire, such as having thick bark etc

Question 10

what temperatures do forest fires burn at

Answer 10

between 540 and 1100 degrees

Question 11

what’s pyrolysis

Answer 11

a chemical reaction causing organic material to decompose as a result of high temperatures

Question 12

what does flaming combustion do

Answer 12

burn wood and organic matter which releases energy

Question 13

how can fire be used as a positive for regeneration

Answer 13

farmers and national park rangers around the world have used controlled burning for years and the minerals that are released from the burning of vegetation are beneficial to the soil

Question 14

what’s a type of species that can withstand fire

Answer 14

baobab tree, because their bark tissue and high moisture content

Question 15

what’s the three stages of a fire

Answer 15

preheating
flaming combustion
glowing combustion

Question 16

what happens during preheating

Answer 16

temperature begins to rise, gases begin to be released and wood breaks down by the process of pyrolysis

Question 17

what happens during flaming combustion

Answer 17

fast burning of wood, cracks develop in wood and releases more gases
energy is released by convection and radiation

Question 18

what happens during glowing combustion

Answer 18

wood burns more slowly and at lower temperature, the fire consumes itself instead of the gases released by pyrolysis

Question 19

what are the two biggest causes of wildfires

Answer 19

an ignition source
fuel

Question 20

what are some examples of ignition sources of wildfires

Answer 20

lightning
climate change
arson
controlled burning
disposable bbq
lava flows

Question 21

are fires usually caused by more natural or human causes

Answer 21

himan

Question 22

what’s the main sauce of fuel for a wildfire

Answer 22

plants or vegetation

Question 23

what’s 5 factors that will affect whether wildfires will start

Answer 23

presence of vegetation
climate
recent weather
wind
topography

Question 24

what percentage of fires are triggered by people

Answer 24

80-90%

Question 25

where do wildfires tend to happen

Answer 25

in rural areas usually but now because of humans they are occurring more in urban areas

Question 26

what two things makes an area most likely to be affected by wildfires

Answer 26

dry vegetation and lightning strikes

Question 27

what 3 semi arid locations are likely to have a wildfire

Answer 27

parts of austria lie USA and canada southern europe like france and italy etc

Question 28

are wild fires seasonal or yearly

Answer 28

usually seasonal

Question 29

what side of the equator do wildfires tend to occur on

Answer 29

south, such as south mercian and africa etc

Question 30

what are species called that can withstand fire

Answer 30

pyrophytic

Question 31

have wildfires impacted tropical rainforests yet

Answer 31

no, due to the humid climate but recent burning for forest clearing have got out of hand

Question 32

what’s a specific area that wildfires have increasingly been a threat too

Answer 32

LA, California

Question 33

what’s three reasons LA suffered many wildfires

Answer 33

-much of the area is covered by drought resistant chaparral, as the area is too dry for much tree growth -a dry wind called santa ana that descends from local mountains increases dryness -consists of low density buildings where vegetation is exposed to fire risk

Question 34

what’s 3 social impacts of wildfires

Answer 34

-people may become trapped and killed -communities may be split up if people move away following a fire -visibility will be reduced by smoke and can cause accidents

Question 35

what’s 3 economic impacts of wildfires

Answer 35

-wildfires are very expensive for emergency services to tackle -infrastructure can be damaged and needs to be replaced -timber can be burned the industry provides jobs and income

Question 36

what’s 3 environmental impacts of wildfires

Answer 36

- some fires may benefit the ecosystem by clearing vegetation -the structure of soil can be altered even it is exposed to high temperatures -larger species of wildfire may be driven from an area by fire

Question 37

what’s two responses to wildfires in terms of preparedness

Answer 37

-education, governments tend to provide guidance for people for explain warning systems and evacuation routes etc -computer modelling, to understand and predict fire behaviour, studying ways to prepare for fires etc

Question 38

what’s a response to fires in the short term

Answer 38

-sending out humanitarian aid, search and rescue teams, emergency services etc

Question 39

what’s an example of a response to fires in terms of mitigation

Answer 39

The colarado state forest service, encourage the creation of fire adapted communities, providing home wonders and communities with advice on how to reduce property damage by fire

Question 40

what’s an example of adaptation in response to a wildfire

Answer 40

Montecito, residents have to adapt by having a 35 meter space around their home built out of ember and fire resistant materials