Lesson 3: What’s necessary for a fire to start?
Discover how fires and wildfires start. Including the Fire Triangle, the main causes of wildfires in Portugal and ideal conditions for Cold Fire.
Lesson 3: What’s necessary for a fire to start?
Discover how fires and wildfires start. Including the Fire Triangle, the main causes of wildfires in Portugal and ideal conditions for Cold Fire.
What’s necessary for a fire to start
We will need to have three components:
- the vegetation which is the fuel,
- the oxygen, as oxidant
- the source of ignition which is the heat
Vegetation (fuel)
Oxygen (oxididant )
Ignition Source (heat)
How wildfires start in Portugal
In Portugal we have a lot of dry thunderstorms: there are no thunderstorms without having humidity and clouds that will cause them, what happens is that the water does not reach down here.
But the great number of ignitions are those that result from human activity, mainly activity that has to do with agricultural practices or that have to do with bonfires or accidents with machinery.
Small Branches
Weeds
Leaves
Pinecones
Pine needles
What burns more easily?
They are thin and dry fuels, such as grass and leaves, because the behaviour of the fire will depend a lot on the humidity that the plants have, and it is these smaller, thinner ones that dry more easily.
So, we’ve already seen that, to burn, the behaviour of fire will depend on the vegetation and the weather, because the weather will affect the vegetation.
What burns more easily?
Small Branches
Weeds
Leaves
Pinecones
Pine needles
They are thin and dry fuels, such as grass and leaves, because the behaviour of the fire will depend a lot on the humidity that the plants have, and it is these smaller, thinner ones that dry more easily.
So, we’ve already seen that, to burn, the behaviour of fire will depend on the vegetation and the weather, because the weather will affect the vegetation.
IPMA
Queimas e Queimadas
What to do if we want to burn? – in Portugal
If we are going to burn, we are going to make a bonfire or we are going to make an extensive burn, one of the first steps we must take is:
- Go to the IPMA➚ website to see if we have conditions to burn. If we’re up to high fire risk, we can burn. For other countries in Europe, we can check the page Before a Fire.
- We always must ask for authorization, either at the city council, or go to the Queimas e Queimadas➚ (ICNF) website and ask for authorization to burn on the specific day and knowing if we have the ideal conditions to make this fire.
What to do if we want to burn? – in Portugal
If we are going to burn, we are going to make a bonfire or we are going to make an extensive burn, one of the first steps we must take is:
- Go to the IPMA➚ website to see if we have conditions to burn. If we’re up to high fire risk, we can burn. For other countries in Europe, we can check the page Before a Fire.
- We always must ask for authorization, either at the city council, or go to the Queimas e Queimadas➚ (ICNF) website and ask for authorization to burn on the specific day and knowing if we have the ideal conditions to make this fire.
IPMA
Queimas e Queimadas
Ideal conditions for Cold Fire
Humidity
Temperature
Wind
What are the ideal conditions for burning?
On the IPMA website we can find out what the humidity, temperature and wind are.
To burn we must have ideal conditions, so that the fire does not escape. In this case we will have:
- the humidity must be between 30% and 70%. If it’s more than 70%, it probably won’t burn, if it’s less than 30% it could burn very easily and very intensely and we don’t want that.
- The wind must be less than 15 km/h, which is the moderate wind, if it is too strong, the flame may jump and may cause a wildfire.
- And the temperature, more than 25ºC, it’s already summer, we don’t want to burn in summer. And therefore, we must have a temperature between 0 and 20 degrees.
- If we have the weather wheel all green, we can safely burn.
The fire is yours, the responsibility is yours.
What are the ideal conditions for burning?
On the IPMA website we can find out what the humidity, temperature and wind are.
To burn we must have ideal conditions, so that the fire does not escape. In this case we will have:
- The wind must be less than 15 km/h, which is the moderate wind, if it is too strong, the flame may jump and may cause a wildfire.
- And the temperature, more than 25ºC, it’s already summer, we don’t want to burn in summer. And therefore, we must have a temperature between 0 and 20 degrees.
- If we have the weather wheel all green, we can safely burn.
The fire is yours, the responsibility is yours.
Ideal conditions for Cold Fire
Humidity
Temperature
Wind
