UB study links fire prevention efforts to fire and burned area reduction in Catalonia
The number of fires and burned hectares in Catalonia has decreased since 1970, although temperature increase and other climate variables raise the risk of fires. A study led by the University of Barcelona (UB) and the Italian National Research Council (CNR) and published in the journal Climate Change, proves that the decrease is due to fire management and prevention measures and citizensʼ awareness campaigns. Researchers have applied a mathematic framework that allows differentiating the influence of climate variables from changes in human fire suppression measures. In addition, they have used this methodology to predict how climate change will affect wildfires in the next years; an increase in the number of fires but a decrease in burned hectares has been forecast. The study is one of the first works on wildfire prediction and is signed by Maria del Carme Llasat, professor from the Department of Astronomy and Meteorology of UB, and researchers Marco Turco, Jost von Hardenberg and Antonello Provenzale, from the Institute of Atmospheric Sciences and Climate (ISAC).
The number of fires and burned hectares in Catalonia has decreased since 1970, although temperature increase and other climate variables raise the risk of fires. A study led by the University of Barcelona (UB) and the Italian National Research Council (CNR) and published in the journal Climate Change, proves that the decrease is due to fire management and prevention measures and citizensʼ awareness campaigns. Researchers have applied a mathematic framework that allows differentiating the influence of climate variables from changes in human fire suppression measures. In addition, they have used this methodology to predict how climate change will affect wildfires in the next years; an increase in the number of fires but a decrease in burned hectares has been forecast. The study is one of the first works on wildfire prediction and is signed by Maria del Carme Llasat, professor from the Department of Astronomy and Meteorology of UB, and researchers Marco Turco, Jost von Hardenberg and Antonello Provenzale, from the Institute of Atmospheric Sciences and Climate (ISAC).
The mathematical framework designed by researchers relates the number of fires that burned more than 0.5 hectares with burned area from 1970 to 2007, according to temperatures (maximum and minimum), precipitations and the number of consecutive dry days. “This framework enables us to know how wildfires would have evolved considering only climate variables; then, we compare it with how they really evolved”, explains Maria del Carme Llasat, head of the group Meteorological Hazard Analysis (GAMA) of UB. “Therefore, we will be able to know the influence that humans have exerted on wildfire control and management. Results show a decrease in the number of fires and burned hectares in the studied period of time”, points out the author.
According to Llasat, results are very positive because they show us what would have happened without human intervention: “The decrease in the number of fires is mainly due to fire prevention and management efforts; measures like the generation of daily maps of fire risk, the presence of fire-guard in areas of risk of fire, the use of specific aerial means, the increasing awareness of population, and its coordination with fire-fighters are some of the measures taken”. Moreover, the researcher highlights that “the reduction is not so remarkable in burned area because once a fire has started and spread, climate conditions like wind and high temperatures unable to control the fire until a change in these conditions occurs”.
In a previous study, researchers proved that summer fires, besides being related to summer climate conditions, are correlated with antecedent climate conditions, especially winter and spring ones with a lag time of two years. Results suggest that precipitation and temperature conditions regulate the amount of fuel, as well as its humidity and structure and, thus, forest flammability.
Data concerning fires for these two studies were obtained from the Forest Fire Prevention Service of the Government of Catalonia (SPIF); the information about precipitations and temperatures were got from the high resolution (20 km x 20 km) gridded data set, called Spain02, used to validate climate change scenarios in Spain and is produced by the Spanish Meteorological Agency (AEMET).
Future predictions: more fires but less burned hectares
Departing from this model, the study also makes long-term prediction about the evolution of wildfires. Researchers used temperature, precipitation and dry day forecasts of different future climate change scenarios in Catalonia. Then, they introduced this information into their mathematical model in order to observe the evolution of the number of fires and burned hectares up to 2050. Conclusions show a slight increase in the number of fires but a reduction in burned surface. “It is surprising to observe a reduction in burned hectares in a future scenario characterised by high temperatures and more fires. We find a possible answer to this question in vegetation which acts as fire fuel: climate conditions affect vegetation making it poorer”, explains Llasat.
This prediction does not take into account future improvements regarding fire prevention and suppression measures. “It is necessary to continue implementing prevention measures in order to revert increasing trends”, alerts the researcher.
A model for all Mediterranean countries
The next step that the research team will make is to apply this methodology to a European database of wildfires. “We are working together with the European Commission in order to apply our model to the Mediterranean region. The first phase is about homogenizing data because criteria to record fires change throughout time”, says the researcher. The Mediterranean region is a climate change hot-spot. In this area, wildfires have a significant impact; nearly 50,000 fires burn around 400,000 hectares every year.