Nature of wildfires

What does the nature of the fire depend on?

• types of plants involved

• strength of the winds

• topography of the area in question

• behaviour of the fire itself

what will it largely depend on?

wind as the largest fires occur in dry windy weather with low humidity

pyrophytic(vegetation)

are plants adapted to tolerate fires.Methods of survival include thick bark,tissue with high moisture content and underground storage structures

retardants

chemical sprayed on to fires in order to slow them down.They are composed of nitrates,ammonia,phosphates,sulphates and thickening agents

for a natural fire to occur what two things are needed?

• an ignition source

• fuel

ignition source

in the case of natural fires lightning is by far and away the main cause.Climate will affect the frequency of electrical storms,particularly one in which there is hardly any rainfall.Increasingly fires are the result of human intervention.

what type of human interventions cause fires

• falling power lines

• carelessly discarded cigarettes,children playing with matches

• camp fires

• barbecues

• agricultural fires

fuel

the fuel has to be in sufficient quantity and dry enough to burn. Climate affects the frequency and duration of droughts during which the vegetation and plant litter have an opportunity to accumulate and dry out

climate also affects the type of vegetation that will grow in the area

what areas are the most in risk of wildfires?

Mediterranean and tropical wet season/dry season climates

in Mediterranean climates winter rainfall encourages vegetation growth but hot dry summers with occasional thunderstorms result in a fire hazard

Savana regions it is the summers that are wet and dry winters

primary effects of wildfires

• loss of crops,timber and livestock

• loss of life

• loss of property

• release of toxic gases and particulates

• loss of wildfires

• damage to soil structure and nutrient content

secondary effects

• evacuation

• increased flood risk

preparedness

• education

  in areas affected by fires, governments often produce comprehensive guidance to help authorities and people prepare for fire hazards e.g familiarisation with evacuation routes and roads

• community action

• computer modelling

  this has been employed to understand and predict fire behaviour it involves studying how fires behave to comprehend and predict fire behaviour.

mitigation

to reduce the risk of fire damage to both property and forest long term mitigation must be undertaken

prevention

• education

  can help advise people on how to avoid starting fires e.g not leaving a fire or barbecue unattended and not discarding a lighted cigarette out of a car windows

• managing the vegetation

  clearing areas between trees and other vegetation ahead of wildfire events to create firebreaks helps prevent the spread of a wildfire

dealing with the event as it happens

once a fire has started it has to be dealt with.This involves fighting the fires as they happen which can be potentially very risky and dangerous

adaptation

communities have to adapt in order to live with wildfires

e.g houses must maintain 35m space around the home and heat resistant materials

risk management designed to reduce impacts of wildfires

• ecological restoration

• thinning

• education

ecological restoration

prescribes burning with low intensity best strategy as it is cheap and reduces wildfires

strengths

it prevents bigger fires from happening

reduces fuel

low cost -large scale and sustainable as it works with natural fires

weaknesses

lots of smoke in fire season

public opposition in practice

can lead to law suits

thinning

removes tress creating gaps in between trees

its an alright strategy but it takes time and very coslty

strengths

prevents trees from touching and stops the spread of fires

hyper local fuel reduction in scale of fire

weaknessess

expensive and would take too long

doesnt look as appealing

education

mitigation

evacuation

fire adapted communities

collaboration

not a good strategy as it is unreliable and chaotic

strengths

homeowners reduce fuel around home

firefighters can hace access in emergency

weaknesses

not everyone will comply

people become complacent

poorly communicated

expensive

how is the park model helpful

collates info on the impact on quality of life

and the effect of management in the relief, rehabilitation, and reconstruction stages on quality of life

evaluates attempts at management in terms of their success

learn from past events

guide for aid reconstruction spending

promote sustainable lifestyle in the context of hazards

how helpful was it during camp fire 2018?

the fire was put out by winter rains, despite 5000 firefighters tracking the blaze for 3 weeks

evacuation on order law and poorly communicated

fire services say the plan was fully implemented, and only 85 people died

PGE spent millions on maintenance following agreed regulations

impacts of campfire 2018

lasted a week

burned 123000 acres

30000 people lost their homes

85 people died