Carlos G. Rossa

Instituto Politécnico de Leiria | ESTG · Departamento de Engenharia Mecânica

Fire spread rate in the absence of wind or slope is a function of fuel characteristics and a reasonable surrogate for back fire spread, which is representative of relevant sections of wildfire fronts. We developed two simple empirical functions for estimating fire spread rate under windless conditions in flat terrain, using a total of 421 fires (la...

Aim of study: To develop a fuel moisture content (FMC) attenuation factor for empirical forest fire spread rate (ROS) models in general fire propagation conditions. Methods: The development builds on the assumption that the main FMC-damping effect is a function of fuel ignition energy needs. Main results: The generic FMC attenuation factor was succ...

Predicting wind-driven rate of fire spread (RoS) has been the aim of many studies. Still, a field-tested model for general use, regardless of vegetation type, is currently lacking. We develop an empirical model for wind-aided RoS from laboratory fires (n = 216), assuming that it depends mainly on fire-released energy and on the extension of flame o...

Currently, there is a dispute on whether live fuel moisture content (FMC) should be accounted for when predicting a real-world fire-spread rate (RoS). The laboratory and field data results are conflicting: laboratory trials show a significant effect of live FMC on RoS, which has not been convincingly detected in the field. It has been suggested tha...

Background: Fireline intensity (If) quantifies the power of the fireline and is used for various purposes. If and flame length (Lf) are relatable to each other using an empirical power function, which has been considered fuel-specific. Aims: The aim of this study was to develop generic Lf−If relationships based on a robust set of field head fires f...

Background The study of wildfire interactions (i.e., spread limitation and reburns) is gaining traction as a means of describing the self-limiting process of fire spread in the landscape and has important management implications but has scarcely been attempted in Europe. We examined to what extent previously burned areas restricted the development...

Background The study of wildfire interactions (i.e., spread limitation and reburns) is gaining traction as a means of describing the self-limiting process of fire spread in the landscape and has important management implications but has not been attempted in Europe. We examined to what extent previously burned areas restricted the development of la...

Prescribed burning (PB) is increasingly recognised as a viable, cost-effective technique for reducing wildfire risk. Yet, quantification of the effect of PB on the reduction of wildfire extent in southern Europe is non-existent. We used 35 years of fire mapping data in Portugal to analyse wildfire regime metrics in nine landscapes before (1985–2004...

Adoption of prescribed burning is increasing as the treatment chosen to decrease fuel hazard in southern Europe but little is known about how it affects wildfire activity. We assessed the effectiveness of prescribed burning treatments by analysing the survival of treatment units to wildfire in mainland Portugal (2005-2017). We examined the time-dep...

This study evaluates the effects of prescribed burnings on soil physico-chemical and biological properties in the short term since it is still in the process of evaluation and their effect in Mediterranean pine forest is not understand completely. Prescribed burning was carried out in three plots of mixed Pinus halepensis and Pinus pinaster stands...

Eucalypts, especially blue gum (Eucalyptus globulus), have been extensively planted in Portugal and nowadays dominate most of its forest landscapes. Large-scale forestation programs can intensify fire activity, and blue gum plantations are often viewed as highly flammable due to the nature and structure of the fuel complex. The role of eucalypt pla...

In this work, we present results of laboratory experiments to analyse fire spread in basic ROS (n = 220) and wind-aided (n = 108) conditions and the development of empirical ROS models for a fire front in a generic fuel bed. We built fuel beds from natural vegetation, mimicking real-world litter and shrubs. Shrub-like fuel beds were composed of ver...

Fire behaviour characteristics define the impacts on society and the environment. While wildland fire science has expanded to include the analysis of fire activity and effects across the globe, an understanding of global fire behaviour patterns and its drivers remains incomplete. We utilized the literature and unpublished datasets as sources for co...

We analysed the role of some fuel bed properties on forest fire-spread rate based on the thermal energy balance upon which the well-known fire-spread rate model of Rothermel (1972) was developed, showing that neither fuel bed height, load or density directly influence the thermal energy balance. The influence of such parameters, often inferred from...

Aim of study: To reconcile the effects of live fuel moisture content (FMC) on fire rate of spread (ROS) derived from laboratory and field fires. Methods: The analysis builds on evidence from previous fire-spread experimental studies and on a comparison between two functions for the FMC damping effect: one derived from field burns, based on dead FMC...

A laboratory experimental program addressing fire spread in fuel beds composed of dead foliage litter and vertically placed quasi-live branches, representative of many natural fuel complexes, was carried out for either still air or wind conditions. Fuel bed characteristics, fire spread rate, flame geometry and fuel consumption were assessed and emp...

Most studies on the effect of fuel moisture content (FMC) on forest fire behaviour focus on dead fuel moisture; mechanisms of fire spread in live vegetation have been considered unexplained by current theory and modelling. In this work, an empirical model for quantifying the effect of FMC on the ratio between spread rate and fuel bed height of fire...

Observational evidence of an effect of live vegetation moisture content on fire-spread rate remains extremely scarce despite the significance of fire activity in fuel complexes dominated by live components. This study assessed the moisture content effect of quasi-live fuels on fire-spread rates measured in laboratory experiments. Fuel beds were bui...

This poster illustrates fire behaviour in blue gum (Eucalyptus globulus) plantations in Portugal under low-to-moderate fire danger as per the Canadian Forest Fire Weather (FWI) System. The observations result from an experimental burning program in 7 to 11-year-old stands carrying fuel loads of 10-15 t ha-1 and with minimum understorey cover (<20%)...

Many methods exist for estimating the moisture of dead fine fuels but the same does not happen for live fuels, since their water content is largely controlled by internal physiological mechanisms within the plant and therefore more difficult to assess. The commonly accepted reference method for measuring fuel moisture content is oven drying, which...

Laboratory experiments of backing fires with slope (-60 to 0°) and wind (-4.5 to 0ms-1) were carried out in fuel beds of dead Pinus pinaster Ait. needles and straw at a 0.6-kgm-2 fuel load, evaluating rates of spread and flame geometry. Wind velocity measurements inside and above the fuel beds were also carried out. Increase in fuel moisture conten...

Eruptive fires are one of the main causes of human losses in forest fire fighting. The sudden change in fire behaviour due to a fire eruption is extremely dangerous for fire-fighters because it is unpredictable. Very little literature is available to support either modelling or occurrence prediction for this phenomenon. In this study, an unsteady p...

The first aim of this work is to provide an analytical expression to calculate the rate of spread of surface fires under no wind and no slope conditions. A previous simplified model was improved for this particular case of fire propagation. The test of this proposed model was performed by using two complete sets of experimental results with several...

Fire eruption is a significant threat to the safety of wildland fire fighters. Over the last few years, several accidents have caused important human losses. Generally, these fire fighters are surprised by the sudden acceleration of the head fire and they are not prepared for facing it. We characterize eruptive fires by an unexpected increasing of...

When two fires approach each other, convective and radiative heat transfer processes are greatly enhanced. The interaction between two linear fire fronts making an angle θoi between them is of particular interest as it produces a very rapid advance of their intersection point with intense radiation and convection activity in the space between the f...

The first aim of this work is to provide an analytical expression to calculate the rate of spread of surface fires under no wind and no slope conditions. A previous simplified model was improved for this particular case of fire propagation. The test of this proposed model was performed by using two complete sets of experimental results with several...

The concepts of fire line rotation and fire line extension are introduced as a complement to the usual rate of spread to describe the movement of surface fires. It is shown that both rotation and translation of the fire line elements contribute to increasing their length and reducing the curvature of the fire line. It is shown that in the case when...

Human activities namely forest management interact with natural conditions to determine fire occurrence and fire impact in a complex form. Climate change tends to facilitate even larger and more dangerous fires. The wildland urban interface is an emerging problem derived from the expansion of urban areas associated to high risk fire conditions. Ext...

The biggest fire fighting accident in the history of Croatia happened on August 30, 2007. The routine fire fighting operation ended with 12 dead and 1 badly injured fire-fighter. That was the biggest human loss in the history of fire fighting in Croatia. In order to understand the Kornati accident a research team was formed and independent scientif...

The interaction of wind, terrain and a fire burning in a landscape can produce a variety of unusual yet significant effects on fire propagation. Moreover, there is strong evidence to suggest that such effects played an important role in driving the spread of large wildfires such as the January 2003 alpine fires over southeastern Australia, the Febr...