Dr. Eduardo Peña F.
Specialist in Fire Ecology
Faculty of Forestry Sciences
University of Concepción
In current climate conditions favourable for their occurrence and high spreading, rural wildfires can’t be controled and extinguished, putting in risk not just vegetation but also villages and entire cities. The cases of mega wildfires with severe impact are already long-established and countless in Australia, the United States, Spain, Portugal and Russia. In Chile, this big hazard showed its worst face in 2017 when the biggest rural wildfire in our history happened, but three years earlier, the worst urban wildfire happened in Valparaíso, burning more than 2.900 homes.
The current 2019-2020 fire season shows a threatening start for Valparaíso. Fire affects every type of vegetation, despite the existence of a belief that native vegetation doesn’t burn at the same intensity as a forest plantation does, but the Cochrane wildfire in February 2019 (more than 15.000 hectares) and the big wildfire still affecting the Amazon are a proof that there are no zones free of fire action.
On the other side, it’s proved in all these events that technical means for combat are not enough or, technically, there is no capacity to control these big events effectively. Neither traditional prevention like education, dissemination and legislation have had a major impact on reducing the problem, either in Chile or throughout the world.
As a result, it’s clear that we must switch from a protection strategy to one more adapted to climate change and a human community still making fires irresponsibly.
As done in Australia in 2009, when big wildfires killed more than 170 people, it’s assumed since then that, when having fuel, wildfires can’t be stopped. For this reason, it was decided that the best prevention is demanding by law that every rural owner must eliminate fuel within the limits of their properties. Without fuel, there are no fires, and if they happen, fire can be controlled more easily.
Personally and according to my technical knowledge of the issue, we must resign ourselves that rural areas will always burn at different recurrence periods, which are reaching three-to-five-year periods as in the case of the Penco-Dichato area in the Bío Bío Region and some areas in Valparaíso.
For now and as a main solution, we must focus efforts on protecting urban communities, whether they are large towns or small villages. From now on, territory planning must include, as one of many decisive factors for the planning of populated areas, the occurrance of wildfires as a real threat to homes and human lives.
My proposal for Chile is developing isolation rings for communities, leaving 30 metres cleared around each populated area, the enough distance to avoid energy radiation from igniting homes or fire advancing through surface fuel.
But this is not enough, because rural wildfires becoming urban wildfires are mostly caused by ashes flying to the interior of populated areas or houses (they can fly up to 2 km). Therefore, beyond the cleared 30 metres, at other 30-to-50 metres, they must work on reducing forest density (trimming at 4.5 mts. and thinning to leave less than 400 trees per hectare), eliminating fuel to avoid crown fires, those that make the most ashes at longer distances.
But also, the city must clean any trace of fine fuel in backyards and homes, because that’s where ashes get to start urban wildfires. Also, it’s required that every housing complex must have a road or a park at the border with a rural area, in order to have other 15 to 20 metres of safety, which can also facilitate access to fire fighting forces.
The problem is very clear and has been glimpsed since 2000, it has emphasised in the last decade and we don’t have efective actions to mitigate rural wildfires. The cost of these urban isolation rings must be assumed by both sectors; the cities, by sacrificing a part of their urban territory (not building up to the rural limit), and rural owners, by not planting or having forest at city, village or road borders.
Protection from wildfires must be done through laws, in a way to anually check safety conditions in the urban-rural interface or, in the contrary, they don’t do maintenance; recent results from a research work indicate that, in fire-affected areas in Quillón, at least 70% of homes don’t meet prevention measures. For the coming future, cities and rural areas will need to redesign homes and use materials that reduce the burning risk.