Every year, landscape fires cause damages to ecosystems and also threaten residential areas like farms, villages and the perimeters towns and cities. There are many factors that contribute to an increased fire risk, such as high temperatures and prolonged drought periods, the strong winds, the configuration of the fuels on the ground and the extremely flammable vegetation.
The “Fire Triangle” is a simple way of understanding how landscape fires occur. Each side of the triangle represents one of the three components needed to have a fire – oxygen, heat, and fuel. When there is not enough heat generated to sustain the process, when the fuel is exhausted, removed, or isolated, or when oxygen supply is limited, then a side of the triangle is broken and the fire will extinguish.
Heat
A heat source is required for the initial ignition of fire, and heat is also needed to maintain the fire and permit it to spread. Heat allows fire to spread by removing the moisture from nearby fuel, warming the surrounding air, and preheating the fuels in its path, enabling it to spread with greater ease.
Fuel
Fuel is any kind of combustible material. Its readiness for ignition and spread is determined by its moisture content (how wet the fuel is), size and shape, quantity, and the arrangement in which it is distributed within an ecosystem or over the landscape.
Oxygen
Air contains about 21% oxygen, and landscape fires require at least 16% oxygen content to burn. Burning fuels react with oxygen from the surrounding air and release heat and combustion products, e.g. smoke (gas and fine particle emissions), which is dangerous to human health, and glowing embers, which may start new fires).