Large Forest Fires Research Articles

The design and manufacture of a remotely piloted aircraft

The article is a compilation of data regarding the process of designing an UAV wing, generally speaking, and an iteration of the stress calculations made during the research. Therefore, we use the best materials and a design that fits the necessities and requirements of such an airplane. The purpose of the UAV is to have a precise goal, namely to be used by the authorities for the people. Example: flying at low height for the surveillance of a large forest fire or a highway, or even for collecting data regarding the air quality and the percentage of noxious particles in different urban and nonurban areas.

Forest Fire Monitoring System Based on Image Analysis

Large forest fires are very hazardous and often cause greater losses. However, due to the vast coverage of forests and the environmental complexity, monitoring which relies on sensor detection of direct contact almost cannot achieve its monitoring function. In this paper, the author proposes that long-range images will first be acquired and so do the images of a larger dynamic range of the observed region, then an embedded video monitoring system will be formed realizing a dynamic monitoring. With the techniques of dynamic image analysis and processing, dynamic image alarms and control signals can be obtained and such videos will be transmitted over the Internet in real-time. Experiments shows this system respond to fires with a fast speed of less than 20ms and the control of fire is highly accurate with a dynamic image area that is less than 1% of the background area.

Investing in Natural Capital: Using Economic Incentives to Overcome Barriers to Forest Restoration

A legacy of fire suppression and the impacts of climate change have induced a worsening pattern of large and severe forest fires across the western United States. This has spurred action to jump‐start wildfire risk mitigation initiatives. Despite an increase in resources and attention, the persistence of economic impediments has forestalled the successful expansion of forest restoration to a landscape level. The failure to properly account for the full range of costs and benefits from restoration treatments has contributed to the asymmetry between needed action and actual implementation. The valuation of non‐market ecosystem services such as carbon sequestration, along with the ability of ecological restoration to act as an agent of economic stimulus, should be incorporated into the policymaking process. We demonstrate how institutionalizing the economic benefits from both the process and products of forest restoration can strengthen policies for advancing long‐term forest health.

강원 영동지역 봄철 산불대형화 영향 기상요소 분석

In this study, we analyzed the meteorological elements, when large forest fires were occurred, The rate of precipitation was 13% of annual average precipitation. Especially, the stronger wind speed, lower humidity and rainfall than average annual record were the distinct feathers on the year when large forest fire occurred in east coast area in Kangwon region. The average, maximum and maximum instantaneous wind speed was 5.9 m/s, 11.3 m/s and 20.9 m/s when large forest fires occurred. The average, maximum and maximum instantaneous wind speed on large fire occurred were 1.8 m/s, 3.0 m/s and 6.9 m/s faster than and average wind speed when whole forest fires occurred. The results indicated that the large forest fire occurrence had a close correlation with meteorological elements.

Os sistemas de informação geográfica no planeamento estratégico de infra-estruturas de prevenção e supressão de incêndios florestais. Caso de estudo: concelho da Serta

Os grandes incêndios florestais têm sido o fenómeno com mais impacto na perturbação dos espaços florestais. A modelação do comportamento e desenvolvimento espacial de uma frente de fogo contribui para melhorar as decisões de localização de infra-estruturas de apoio à supressão de incêndios florestais.

Combining spectral mixture analysis and object-based classification for fire severity mapping

This study shows an accurate and fast methodology in order to evaluate fire severity classes of large forest fires. A single Landsat Enhanced Thematic Mapper multispectral image was utilized in this study with the aim of mapping fire severity classes (high, moderate and low) using a combined-approach based in an spectral mixing model and object-based image analysis. A large wildfire in the Northwest of Spain is used to test the model. Fraction images obtained by Landsat unmixing were used as input data in the object-based image analysis. A multilevel segmentation and a classification were carried out by using membership functions. This method was compared with other simplest ones in order to evaluate the suitability to distinguish between the three fire severity classes above mentioned. McNemar’s test was used to evaluate the statistical significance of the difference between approaches tested in this study. The combined approach achieved the highest accuracy reaching 97.32% and kappa index of agreement of 95.96% and improving accuracy of individual classes.

Wildfire risk inferred from tree rings in the Central Laurentians of boreal Quebec, Canada

Abstract Recent fire years 2002 and 2005 have been, in the context of the past 40 years, exceptional in Quebec, with area burned totalling over 1.8 million hectares. Without prolonged fire statistics and meteorological records, it remains difficult to place these events in the contexts of climate change and variability. How frequently does this type of year occur? In this study, chronologies of radial increment measurements of Pinus spp., considered reliable back to at least 1821, were calibrated to develop an index of past moisture in ground surface fuels in the Baie-Comeau area of the Central Laurentians ecoregion, Quebec (namely the Canadian Drought Code (CDC)). Over 37% of the variance in CDC observations (period 1901–2000) was recovered by the tree-ring estimates. These estimates in turn correlated well (R2=0.39) with annual area burned (AAB) by large forest fires (size >200 ha; 1959–1999) in the Central Laurentians ecoregion. The smoothed reconstruction showed the prevalence of periods of drier conditions than average from the 1840s to the 1920s, followed by an episode of moister conditions from the 1930s to the 1960s. The minimum occurrence rate of years of extreme wildfire risk in the Baie-Comeau area was estimated in the 1940s at 0.04 yr−1, while the maximum was estimated in the 1910s at 0.21 yr−1. Occurrence rate at the turn of the 21st century (0.21 yr−1) was closely similar to that recorded during the 1890–1910s (within the uncertainty bands). These long-term variations matched temporal variations in a previously published time-since-fire distribution. The combined information from these ecological sources of data provides meaningful insights for future management of wildfire risk in the Baie-Comeau area, notably to increasing adaptation capacity in response to climate change.

Circulation patterns, wildfire risk and wildfire occurrence at continental Spain

Daily weather variability is a major factor affecting the behaviour of wildfires. This paper analyzes the links between atmospheric circulation at synoptic scale, weather conditions influencing fires at regional scale and the occurrence of very large forest fires in continental. A synoptic climatology of the 850 hPa geopotential heights was derived employing multivariate techniques (Principal Component Analysis and Clustering). The catalogue displays the spatial and temporal variability of the atmospheric circulation over the area, reproducing distinctive pressure patterns and seasonal frequency variations. Each pattern shows substantial region-wide differences in the magnitude of weather-related fire risk conditions, corresponding to combinations of controlling climatic factors. Finally, the results emphasise the obligation to combine both short term and long term climate variability to explain the occurrence of episodes of very large wildfires.

Factors influencing the formation of unburned forest islands within the perimeter of a large forest fire

Large forest fires have recently increased in frequency and severity in many ecosystems. Due to the heterogeneity in fuels, weather and topography, these large fires tend to form unburned islands of vegetation. This study focuses on a large forest fire that occurred in north-eastern Spain in 1998, which left large areas of unburned vegetation within its perimeter. Based on a satellite post-fire severity map we searched for the relative influence of biotic and abiotic factors leading to unburned island formation. We divided the area of the fire into individual units we called “slopes” which were meant to separate the differential microclimatic effects of contrasted aspects. The number of unburned islands and their areas were related to 12 variables that influence their formation (i.e. land cover composition, aspect, steepness, forest structure, two landscape indices and weather variables). We hypothesized that unburned vegetation islands would concentrate on northern aspects, in less flammable forests (i.e. broadleaf species) and higher fragmentation to interrupt the advance of fire. While north and western aspects did have a higher presence of unburned vegetation islands, our study suggests greater presence of islands in slopes that are larger (i.e. more continuous areas with relatively homogeneous aspect), with greater proportions of forest cover, with higher wood volumes and with lower proportions of broadleaf species. Climate also played a role, with relative humidity and wind speed positively and negatively correlated to island formation, respectively. Unburned vegetation was more frequent on slopes with lower diversity of land covers and higher dominance of one land cover in the slope. Since slopes with only one land cover (i.e. forests) had more islands than slopes with multiple cover types, we infer that under severe meteorological conditions, fragmented forests can be more affected by wind and by water stress, thus burning more readily than forests that are protected from this edge phenomenon. These results would reinforce forest management strategies that avoid linear features (fire-lines and fire-breaks), to enhance fuel treatments that focus on areas and minimize fragmentation.

Spatio-temporal perspectives of forest fires regimes in a maturing Mediterranean mixed pine landscape

It has been suggested that during the past several decades, the frequency and the intensity of wildfires have markedly increased in the Mediterranean basin. We came to assess this postulation in the forested region of Mount Carmel, Israel. This region is characterized by Quercus spp. and Pistacia spp. maquis and has been intensely afforested with Pinus spp. stands since the 1920s. We compiled a GIS-based database of the fires recorded in the region since 1983, in addition to archiving data beginning from the 1940s. The data were collected from land stewardship agencies’ archives, fire departments and aerial photographs. Prior to the early 1980s, no systematic documentation of the fires was available, rather just sporadic qualitative documentation of the large forest fires that occurred. Between 1944 and 1982, only 6 large fires were documented, while after that 11 large fires occurred. Analysis indicated that the spatial distribution of the fires does not occur at random, and their locations are significantly closer to roadsides compared to an expected random distribution. The annual number of fires and the areas burned during the last two decades were not correlated with annual precipitation in any manner. Accordingly, we suggest that the increased number of large forest fires during the last decades is associated with the maturation and senescence of the planted forest coupled with increased human activities.

California's Climate Change Program: Lessons for the Nation

I. INTRODUCTION II. THE IMPERATIVE OF STATE CLIMATE ACTION A. Exercise of a State's Police Powers to Protect Public Health and Its Natural Resources B. Exercise of the State's Policy Prerogative: Laboratory of Democracy C. Future National Climate Policy Framework: A Federal-State-Local Partnership III. CALIFORNIA'S MODEL OF POLICY DEVELOPMENT: LEADERSHIP, CROSS-AGENCY ENGAGEMENT, AND STAKEHOLDER INVOLVEMENT A. Consistent Leadership B. Efforts by California's State Agency Climate Action Team C. Stakeholders: Local Governmental Agencies, Industry, NGOs and Individuals IV. MULTIPLE CHALLENGES, MULTIPLE TOOLS A. Governor Arnold Schwarzenegger's Climate Change Executive Orders B. California's Assembly Bill 32 Framework: Markets and Mandates C. California's Upcoming Development of a Cap-and-Trade Program V. COMPREHENSIVE POLICY EXAMPLE: TRANSPORTATION SECTOR A. California's Passenger Vehicles Greenhouse Gas Regulation: The Parley Standards B. California's Low-Carbon Fuel Standard C. Senate Bill 375: Land Use, Vehicle Miles Traveled, and Greenhouse Gas Reductions Through Incentives VI. CALIFORNIA'S HARD-WON CLIMATE CHANGE LESSONS FOR THE NATION A. Demonstrate Clear and Determined Leadership B. Act Now C. Set a Specific, Declining Emissions Cap D. Engage Government and the Private Sector at All Levels and in All Silos. E. Federal Policy Must Engage the Effort of Stakeholders and Citizens from Across the Political and Economic Spectrum I. INTRODUCTION Climate change is a real and urgent threat to our communities, our states and our nation. California, like many other states, is already experiencing its impacts. Over the past 100 years, the Golden State has seen a seven-inch rise in sea level, eroding our coastal communities and threatening critical infrastructure. (1) In the winter, more of our precipitation now falls as rain rather than snow, leading to less water availability in the critical spring and summer months--an impact that threatens one of the most productive agricultural regions in the world and a pillar of the nation's export economy. (2) Climate change is also a major factor in California's longer and more severe wildfire season--an impact dramatically illustrated in 2008 when over 1 million acres burned and air quality monitors were overwhelmed in efforts to measure record-breaking levels of particulate matter. And these effects are merely a preview. It is predicted that without major efforts to reduce greenhouse gases, in this century California will see an additional one- to two-foot rise in sea levels, a doubling in the frequency of drought years, a 55 percent increase of large forest fires and a 75 percent loss in California's snowpack, our state's biggest natural reservoir. (3) These threats are mirrored around our nation and around the globe. I emphasize them to underscore my contention that the nation must follow California's lead by taking swift, decisive and comprehensive action to address climate change. Not only is climate change an urgent and dire threat, it is also a complex one. The combustion of fossil fuels is a major source of greenhouse gas emissions, but by no means the only one. Sources as diverse as agriculture, forestry and industrial processes also contribute to climate change. Cutting emissions from these sources will require a multifaceted response that includes a variety of regulatory, market-based and voluntary actions undertaken at all levels of government, industry and society. And, like the diversity of sources that contribute to climate change, the opportunities to reduce emissions--and the economic opportunities to create new, clean technologies--vary between different industries, regions and individuals. …

A stochastic forest fire growth model

We consider a stochastic fire growth model, with the aim of predicting the behaviour of large forest fires. Such a model can describe not only average growth, but also the variability of the growth. Implementing such a model in a computing environment allows one to obtain probability contour plots, burn size distributions, and distributions of time to specified events. Such a model also allows the incorporation of a stochastic spotting mechanism.

PAST AND FUTURE CHANGES IN CANADIAN BOREAL WILDFIRE ACTIVITY

Climate change in Canadian boreal forests is usually associated with increased drought severity and fire activity. However, future fire activity could well be within the range of values experienced during the preindustrial period. In this study, we contrast 21st century forecasts of fire occurrence (FireOcc, number of large forest fires per year) in the southern part of the Boreal Shield, Canada, with the historical range of the past 240 years statistically reconstructed from tree-ring width data. First, a historical relationship between drought indices and FireOcc is developed over the calibration period 1959-1998. Next, together with seven tree-ring based drought reconstructions covering the last 240 years and simulations from the CGCM3 and ECHAM4 global climate models, the calibration model is used to estimate past (prior to 1959) and future (post 1999) FireOcc. Last, time-dependent changes in mean FireOcc and in the occurrence rate of extreme fire years are evaluated with the aid of advanced methods of statistical time series analysis. Results suggest that the increase in precipitation projected toward the end of the 21st century will be insufficient to compensate for increasing temperatures and will be insufficient to maintain potential evapotranspiration at current levels. Limited moisture availability would cause FireOcc to increase as well. But will future FireOcc exceed its historical range? The results obtained from our approach suggest high probabilities of seeing future FireOcc reach the upper limit of the historical range. Predictions, which are essentially weighed on northwestern Ontario and eastern boreal Manitoba, indicate that, by 2061-2100, typical FireOcc could increase by more than 34% when compared with the past two centuries. Increases in fire activity as projected by this study could negatively affect the implementation in the next century of forest management inspired by historical or natural disturbance dynamics. This approach is indeed feasible only if current and future fire activities are sufficiently low compared with the preindustrial fire activity, so a substitution of fire by forest management could occur without elevating the overall frequency of disturbance. Conceivable management options will likely have to be directed toward minimizing the adverse impacts of the increasing fire activity.

Solar activity as a possible cause of large forest fires — A case study: Analysis of the Portuguese forest fires

Fires of large dimension destroy forests, harvests and housing objects. Apart from that combustion products and burned surfaces become large ecological problems. Very often fires emerge simultaneously on different locations of a region so a question could be asked if they always have been a consequence of negligence, pyromania, high temperatures or maybe there has been some other cause. This paper is an attempt of establishing the possible connection between forest fires that numerous satellites registered and activities happening on the Sun immediately before fires ignite. Fires emerged on relatively large areas from Portugal and Spain on August 2005, as well as on other regions of Europe. The cases that have been analyzed show that, in every concrete situation, an emission of strong electromagnetic and thermal corpuscular energy from highly energetic regions that were in geo-effective position had preceded the fires. Such emissions have, usually, very high energy and high speeds of particles and come from coronary holes that also have been either in the very structure or in the immediate closeness of the geo-effective position. It should also be noted that the solar wind directed towards the Earth becomes weaker with deeper penetration towards the topographic surface. However, the results presented in this paper suggest that, there is a strong causality relationship between solar activity and the ignition of these forest fires taking place in South-western Europe.

A distributed framework for multi-risk assessment of natural hazards used to model the effects of forest fire on hydrology and sediment yield

Within the European Commission-funded MEDIGRID project, Grid computing technology is used to integrate various natural hazard models and data sets, maintained independently at different centres in Europe, into a single system, accessible to users over the internet. Each centre forms a process (application) or data storage node and has been fitted with the Globus toolkit, which provides the distributed computing environment functionality that is required for the system set up. In addition, several Grid data management components were developed to allow the system to operate on different computing platforms. Access to the data and application management services is enabled through a Grid Portal. A series of portlets enable users to access the system, providing a personalised interface to the Grid. Integration of the individual models required them to be modified as web services, so as to be run remotely over the internet. As the models have different data characteristics, a common data format was adopted for creating harmonised data sets and allowing the exchange of data between the models. As an example, the Fire Spread Engine model is used to derive a map of areas that have been burnt by fire. This forms an input to the SHETRAN hydrology, soil erosion and landslide model, which in turn could provide data for other models such as vegetation regeneration. The use of the system is demonstrated for a site in south-west Spain where a large forest fire occurred on 2 August 2003. The MEDIGRID system marks an advance in the integration of independently constructed models to provide improved hazard assessment technology.

A Stochastic Model for Forest Fire Growth

We consider a stochastic fire growth model, with the aim of predicting the behavior of large forest fires. Such a model can describe not only average growth, but also the variability of the growth. Fire is modeled as a random phenomenon on a regular spatial grid, specifically, an interacting particle system modeled as a continuous-time Markov chain on a lattice. Each lattice site changes state according to local transition rates, which model the competing physical processes of fire spread, spotting, and burnout. The rate functions, which are currently tentative, could be based on topography, fuel moisture, and local weather. Implementing such a model in a computing environment allows one to obtain probability contour plots, burn size distributions, and distributions of time to specified events. Such a model also allows the incorporation of a stochastic spotting mechanism.

Current perturbations of the north patagonian chilean forest derived of the effects of large forest fires occurred half a century ago. Preliminary study in the andean basin of the Figueroa River

Current perturbations of the north patagonian chilean forest derived of the effects of large forest fires occurred half a century ago. Preliminary study in the andean basin of the Figueroa River

Small-scale mixing processes enhancing troposphere-to-stratosphere transport by pyro-cumulonimbus storms

Abstract. Deep convection induced by large forest fires is an efficient mechanism for transport of aerosol particles and trace gases into the upper troposphere and lower stratosphere (UT/LS). For many pyro-cumulonimbus clouds (pyroCbs) as well as other cases of severe convection without fire forcing, radiometric observations of cloud tops in the thermal infrared (IR) reveal characteristic structures, featuring a region of relatively high brightness temperatures (warm center) surrounded by a U-shaped region of low brightness temperatures. We performed a numerical simulation of a specific case study of pyroCb using a non-hydrostatic cloud resolving model with a two-moment cloud microphysics parameterization and a prognostic turbulence scheme. The model is able to reproduce the thermal IR structure as observed from satellite radiometry. Our findings establish a close link between the observed temperature pattern and small-scale mixing processes atop and downwind of the overshooting dome of the pyroCb. Such small-scale mixing processes are strongly enhanced by the formation and breaking of a stationary gravity wave induced by the overshoot. They are found to increase the stratospheric penetration of the smoke by up to almost 30 K and thus are of major significance for irreversible transport of forest fire smoke into the lower stratosphere.

Integration of socio-economic and environmental variables for modelling long-term fire danger in Southern Europe

In Mediterranean forests fire danger assessment is of crucial importance for any fire prevention policy, both at the local and global scale. The objective of this study is to model large scale structural forest fire danger in Southern Europe. This was done through the identification of those physiographic, socioeconomic and environmental factors that best explain fire occurrence in this region. The modeling process consisted of a multi-step analysis based on multiple regression techniques. In this work, a balance is reached between the objectivity of mechanical methods, and the thoroughness entailed by an exhaustive selection of the variables. Due to the different availability of input data, two different fire danger models were built. One model was derived for Portugal, Spain, France, Italy and Greece, using an initial set of 32 independent variables. A second model was derived for a reduced area (Spain, France and Italy) using these 32 plus another 5 variables. Both models were built using the same methodology, which was based on the search for best intermediate models. The dependent variable used to represent forest fire danger was computed through the annual average of fire occurrence. Statistically, both models performed satisfactorily. The final fits for the first and second model yielded R 2 values of 0.60 and 0.71, respectively. Given the structural condition of the variables considered, the resulting models can be used to support the design of fire prevention policies on the long-term basis.

On large scale forest fires propagation models

The question of the modeling of forest fires at large scales is addressed. Empirical models are compared and it is shown that Rothermel's model describing the rate of spread of a straight front is included in the envelope model which in turn is included in a Hamilton–Jacobi equation description. This result shows that the preceding models could be included in reaction diffusion systems. Then an anisotropic propagation model with a nonlocal radiative term, obtained by asymptotic expansion of a combustion modeling, is proposed. This modeling takes into account the effects of wind and slope and it is shown that this type of modeling is the simplest generalization of the empirical ones.