Lecture 10 Wild fires

Question 1

what is the history of wildfires

Answer 1

increase 10,000 years ago maybe due to warmer drier climate, increased used of fire by humans

Question 2

what are the requirements for wildfires

Answer 2

fuel, oxygen, heats, if any are lost fire will dissipate

Question 3

descrbe the pre ignitation phase

Answer 3

pre heating: vegeation reaches a temp at which can ignite
pyrlysis: chemical process of the degration of large hyrocarbons into smaller ones occurs in the presence of heat
preheating and pyrolyss result in feul that is prone to ignite,

Question 4

describe the combustion phase

Answer 4

starts with ignition (not a single process, not every ignition will result in a while fire) two types of combustion; flaming and smoldering

Question 5

describe flaming combustion

Answer 5

shifts rapidly, high temp converison of fuel into heat, flames and large amounts of burned material

Question 6

describe smoldering combustion

Answer 6

occurs in area with burend material as ash covers is a new fuel

Question 7

what are the transfers of heat

Answer 7

condition, moleucle to molecule contact
radiation; transfer of heat in the for of invisble waces
convection; transer of heat by movement of liquf or gas

Question 8

describe the heat transfer by wildfires

Answer 8

heat fors raadiation in inainly radiation an onection, as the air is heated it becomes less dense and rises, the rising are removes heat fro the zone of flaming and is replaced by fresh air, this fresh air oxxygen sustains cobustion

Question 9

what is the extinction phase

Answer 9

point at which combustion ceases, there is no longer heat of feul to sustain a fire

Question 10

describe feul

Answer 10

anything off the ground, dieases and stroms leads to more ecaying matieral that burns easy

Question 11

how does fuel conent vary by slope orientation

Answer 11

in NA south facing slopes are relativety warm and dry, slopes ecosed to prevailing winds are often drier, wildfire burin on steep sloes preheat fuel upslope reultin in spreading of fire upslope

Question 12

what are dry thunderstorms

Answer 12

lighenting prodces whildfries by the rain evaporates before reaching the ground, wind carried embers that ignite spot fires

Question 13

what are the types of wildfies

Answer 13

calissifed accordin o the layer of fuel
surface; ravel close to the round burning shrubs and leaves
crown fires: move rapidly throgh the forest canopy byflaming combustion

Question 14

what are the types of crown fires

Answer 14

intermittent crown fires; consume tops of some trees

contionious corwn fire; consumes the tops of all tree

Question 15

wwhat are the effects of wildfires

Answer 15

fires that burn soil leave behind a hydrophobic layer at the surface which increases runoff an erosion, may persist for several years,
wildfires increae the amount of particle sin the atmosphere which can persist for weeks

Question 16

what are the linages to climate change

Answer 16

may increase the intensity of wildfires
cause severe drought
forest will expand northward
insect infectation can cause disease making forests more vulnerable

Question 17

what is the mointain pine bettle

Answer 17

destyes canadian forests, 80% of all mature ress are impacted, consequencewill be felt for decades in BC

Question 18

what are the impact of wildfire

Answer 18

an lea to evacuation of entire towns, road closures, airport closures, severe property loss, organized evacation has minimized amount of deaths

Question 19

wha are the impacts of wildfires to animals

Answer 19

most can escape unharmed, rodents can take refuge undergound, can produce open areas sutied for grazing (natural ervice function)

Question 20

what are the naural service function of wild fires

Answer 20

emprally reduces competition for sunught, some speices triggers relsease of seeds, ash is carbon rich, can remoe microorganisms, removes surface litter

Question 21

describe yellow stone national park

Answer 21

j

Question 22

what is fire mamagement

Answer 22

objective is to control wildfires for the benefit of ecosystes while preenting them from harming people and property reuqires research of the fire regine (otential for a wild fire)

Question 23

wat is fire supression

Answer 23

a stregety to steer the fire into an area with no fuel (natural breaks). reliance of fire supression leds to a buildup of fuel in forest and potential for intense fire

Question 24

what are perscribed burns

Answer 24

one way to conter the buildup of fuel, purpsofuly ignited to reduce the amount of fuel in forests