Wildland Fire Hazard Research Articles

Reducing wildland fire hazard exploiting complex network theory: A case study analysis

We discuss a new systematic methodology to mitigate wildland fire hazard by appropriately distributing fuel breaks in space. In particular, motivated by the concept of information flow in complex networks we create a hierarchical allocation of the landscape patches that facilitate the fire propagation based on the Bonacich centrality. Reducing the fuel load in these critical patches results to lower levels of fire hazard. For illustration purposes we apply the proposed strategy to a real case of wildland fire. In particular we focus on the wildland fire that occurred in Spetses Island, Greece in 1990 and burned the one third of the forest. The efficiency of the proposed strategy is compared against the benchmark of random distribution of fuel breaks for a wide range of fuel breaks densities.

Modelling static fire hazard in a semi-arid region using frequency analysis

Various fire hazard rating systems have been used by many countries at strategic and tactical levels for fire prevention and fire safety programs. Assigning subjective weight to parameters that cause fire hazard has been widely used to model wildland fire hazard. However, these methods are sensitive to experts’ judgements because they are independent of any statistical approaches. Therefore, in the present study, we propose a wildland fire hazard method based on frequency analysis (i.e. a probability distribution model) to identify the locations of fire hazard in north-eastern Iran, which has frequent fire. The proposed methodology uses factors that do not change or change very slowly over time to identify static fire hazard areas, such as vegetation moisture, slope, aspect, elevation, distance from roads and proximity to settlements, as essential parameters. Several probability distributions are assigned to each factor to show the possibility of fire using non-linear regressions. The results show that approximately 86% of MODerate-resolution Imaging Spectroradiometer (MODIS) hot spot data are located truly in the high fire hazard areas as identified in the present study and the most significant contributing factor to fire in Golestan Province, Iran, is elevation. The present study also reveals that approximately 14% of the total study area (~20 368 km2) has a fire hazard of 66%, which can be considered very high. Therefore, this area – located mostly in the central, west and north-east regions of Golestan Province – should be considered for an effective conservation strategy of wildland fire.

Using fine-scale fuel measurements to assess wildland fuels, potential fire behavior and hazard mitigation treatments in the southeastern USA

The inherent spatial and temporal heterogeneity of fuelbeds in forests of the southeastern United States may require fine scale fuel measurements for providing reliable fire hazard and fuel treatment effectiveness estimates. In a series of five papers, an intensive, fine scale fuel inventory from the Savanna River Site in the southeastern United States is used for building fuelbeds and mapping fire behavior potential, evaluating fuel treatment options for effectiveness, and providing a comparative analysis of landscape modeled fire behavior using three different data sources including the Fuel Characteristic Classification System, LANDFIRE, and the Southern Wildfire Risk Assessment. The research demonstrates that fine scale fuel measurements associated with fuel inventories repeated over time can be used to assess broad scale wildland fire potential and hazard mitigation treatment effectiveness in the southeastern USA and similar fire prone regions. Additional investigations will be needed to modify and improve these processes and capture the true potential of these fine scale data sets for fire and fuel management planning.

Decision support system for forest fire protection in the Euro-Mediterranean region

This paper describes the development of a decision support system (DSS) for prevention planning and emergency management of forest fire events that incorporates weather data management, a geographical data viewer, a priori danger forecasting and fire propagation modeling, automatic fire detection, and optimal resource dispatching. Collection, input, storage, management, and analysis of the information rely on advanced and automated methodologies using remote sensing, GPS, digital mapping, and geographic information systems. The results included short-term dynamic fire danger indices developed for improved and realistic prevention and pre-suppression planning. An automatic fire detection technology based on infrared video was developed and successfully tested on site. Several models for understanding fire propagation on forest fires have been proposed for practical application. Additionally, a DSS was developed with the innovation of covering wildland fire hazard management entirely, providing a complete coverage of technical and administrative activities that support decision makers in real time. The DSS was tested for high fire seasons in two different sites in South Europe.

Guiding preventative wildland fire mitigation policy and decisions with an economic modeling system

The protection of private residences from wildland fire produces high levels of cost and safety risk to firefighters, especially with the expanding ex-urban settlement pattern in the wildland urban interface (WUI). Economic information on probable structure losses can help guide efficient wildfire management, policy, and investments. However, no single existing modeling tool is capable of accurately predicting existing wildland fire ignition risk to WUI residences, nor are there broadly accepted models to calculate needed investments to reduce risk to WUI structures. To fill this void, a representative set of rural residences in western Montana was selected to estimate a baseline, 30-year wildland fire ignition hazard and the cost effectiveness of optional investments to reduce risk from wildfire damage to these residences. The study applied a modeling system combining outputs from a structure ignition assessment model (SIAM) with wildland fire probabilities from an ecological disturbance model (SIMPPLLE). Results indicate that the probability of structure damage to a home when a fire visits a residence is 1.0 under conditions of extreme wildland fire weather. This contrasts with the low probabilities (0–0.05) that wildland fire will reach vegetation surrounding the residence. Cost-effectiveness analysis of two suites of preventative mitigation strategies demonstrated that home mitigation zone investments (modifying houses or fuels within 30.5 m (100 ft) of a residence) are generally more cost effective in reducing risk to WUI structures than investments in silvicultural operations in surrounding forests (within 2.4 km (1.5 mi) of homes). The effectiveness of the mitigation options in modifying average home loss due to wildfire ranges from negative 19.6% to positive 63% (some silvicultural treatments did increase the probability of wildfire in simulations). While both home ignition zone mitigations and silvicultural treatments can markedly reduce wildland fire hazard estimates, the former appear to provide a more pronounced reduction in hazard as correlated with expenditures.

Understanding Social Complexity Within the Wildland–Urban Interface: A New Species of Human Habitation?

The lack of knowledge regarding social diversity in the Wildland Urban Interface (WUI) or an in-depth understanding of the ways people living there interact to address common problems is concerning, perhaps even dangerous, given that community action is necessary for successful wildland fire preparedness and natural resource management activities. In this article, we lay out the knowledge and preliminary case study evidence needed to begin systematically documenting the differing levels and types of adaptive capacity WUI communities have for addressing collective problems such as wildland fire hazard. In order to achieve this end, we draw from two theoretical perspectives encompassing humans' interactions with their environment, including (1) Kenneth Wilkinson's interactional approach to community, (2) and certain elements of place literature. We also present case study research on wildfire protection planning in two drastically different California communities to illustrate how social diversity influences adaptive capacity to deal with hazards such as wildland fire. These perspectives promote an image of the WUI not as a monolithic entity but a complex mosaic of communities with different needs and existing capacities for wildland fire and natural resource management.

Wildland fire hazard and risk: Problems, definitions, and context

The risks, hazards, and relative severity of wildland fires are presented here within the ecological context of historical natural fire regimes, time, space, and process. As the public dialogue on the role and impacts of wildland fire increases, it is imperative for all partners to converge on clear and concise terminology that defines risk, hazard, and the characteristic (or uncharacteristic) nature of wildland fire. These terms must be defined in the context of scale—both spatial and temporal. The concept of historical natural fire regimes involves a classification of the characteristic, or “natural” processes and effects associated with wildland fire occurring in sustainable ecosystems. When a wildland fire occurs within the time, space, and severity parameters of the historical natural fire regime, the fire can be called natural, or “characteristic”. The milieu of disturbance effects we call catastrophic, such as economic losses, damages to communities and structures, or impacts on short-term aesthetic values involve social, cultural, and economic values and risks—none is directly associated with ecological values, damages, or risks. In the context of technical risk assessments, the term “risk” considers not only the probability of an event, but also includes values and expected losses. However, within the fire community it refers only to the probability of ignition (both man- and lightning-caused). ‘Hazard’ refers to the state of the fuel, exclusive of weather or the environs in which the fuel is found. Unlike many common uses of the term ‘severity’, fire severity refers specifically to the effect a fire has on wildland systems. It is inappropriate to use the term severity to describe the behavior of the fire phenomenon itself. Instead, we should confine its use to that relating only to a fire's effect. Finally, I discuss the limitations and conflicts to integrating all social, cultural, economic, health, and safety values in our public and policy-forming dialogue relating to fire risk, hazard, and severity. Typical risk assessments consider all relevant endpoints, including socio-economic, management, as well as ecological elements. Herein, I use the Black Mountain 2 Fire from August 2003 in the northern Rockies to illustrate the spatiotemporal extent of fire's impacts on the endpoints. When expressed over all affected spatiotemporal scales, the overlay of all endpoints from this synthetic scenario results in a “decision space” ranging in time from an hour to a century, and in space ranging from a few square meters to the continent.

MAPPING FUELS AND FIRE REGIMES USING REMOTE SENSING, ECOSYSTEM SIMULATION, AND GRADIENT MODELING

Maps of fuels and fire regimes are essential for understanding ecological relationships between wildland fire and landscape structure, composition, and function, and for managing wildland fire hazard and risk with an ecosystem perspective. While critical for successful wildland fire management, there are no standard methods for creating these maps, and spatial data representing these important characteristics of wildland fire are lacking in many areas. We present an integrated approach for mapping fuels and fire regimes using extensive field sampling, remote sensing, ecosystem simulation, and biophysical gradient modeling to create predictive landscape maps of fuels and fire regimes. A main objective was to develop a standardized, repeatable system for creating these maps using spatial data describing important landscape gradients along with straightforward statistical methods. We developed a hierarchical approach to stratifying field sampling to ensure that samples represented variability in a wide variety of ecosystem processes. We used existing and derived spatial layers to develop a modeling database within a Geographic Information System that included 38 mapped variables describing gradients of physiography, spectral characteristics, weather, and biogeochemical cycles for a 5830-km2 study area in northwestern Montana. Using general linear models, discriminant analysis, classification and regression trees, and logistic regression, we created maps of fuel load, fuel model, fire interval, and fire severity based on spatial predictive variables and response variables measured in the field. Independently evaluated accuracies ranged from 51 to 80%. Direct gradient modeling improved map accuracy significantly compared to maps based solely on indirect gradients. By focusing efforts on direct as opposed to indirect gradient modeling, our approach is easily adaptable to mapping potential future conditions under a range of possible management actions or climate scenarios. Our methods are an example of a standard yet flexible approach for mapping fuels and fire regimes over broad areas and at multiple scales. The resulting maps provide fine-grained, broad-scale information to spatially assess both ecosystem integrity and the hazards and risks of wildland fire when making decisions about how best to restore forests of the western United States to within historical ranges and variability.

Cluster analysis of structural stage classes to map wildland fuels in a Madrean ecosystem

Geospatial information technology is changing the nature of fire mapping science and management. Geographic information systems (GIS) and global positioning system technology coupled with remotely sensed data provide powerful tools for mapping, assessing, and understanding the complex spatial phenomena of wildland fuels and fire hazard. The effectiveness of these technologies for fire management still depends on good baseline fuels data since techniques have yet to be developed to directly interrogate understory fuels with remotely sensed data. We couple field data collections with GIS, remote sensing, and hierarchical clustering to characterize and map the variability of wildland fuels within and across vegetation types. One hundred fifty six fuel plots were sampled in eight vegetation types ranging in elevation from 1150 to 2600 m surrounding a Madrean ‘sky island’ mountain range in the southwestern US. Fuel plots within individual vegetation types were divided into classes representing various stages of structural development with unique fuel load characteristics using a hierarchical clustering method. Two Landsat satellite images were then classified into vegetation/fuel classes using a hybrid unsupervised/supervised approach. A back-classification accuracy assessment, which uses the same pixels to test as used to train the classifier, produced an overall Kappa of 50% for the vegetation/fuels map. The map with fuel classes within vegetation type collapsed into single classes was verified with an independent dataset, yielding an overall Kappa of 80%.

Modeling Urban/Wildland Interface Fire Hazards within a Geographic Information System

Abstract This paper models and assesses the risk of a class of uncontrollable fire, firestorms in the East Bay hills, San Francisco Bay, California. A Geographic Information System (GIS) is constructed which provides R frame-work For quantifying fine hazard in a heterogeneous landscape. Two models, one to assess the wildland fire hazard and the other to assess the urban/residential fire hazard, are integrated and embedded within the GIS to map regional and neighbourhood risk. The models generate a hazard assessment map comprised of polygons which represent the results of quantitative multivariate analysis. The system allows for future adjustment of one or all of the parameters as policy is implemented and hazardous conditions are mitigated. This features provides a mechanism for accounting and feedback allowing for the appraisal of the success of mitigation.

The risk perceptions and policy response toward wildland fire hazards by urban home-owners

Expanding urban areas have brought an increasing number of people into close proximity to extensively managed wildland, creating a new natural hazard — the wildland fire hazard. Public officials in Southern California, for example, have suggested programs for protecting urban residents. This study examines why the urban public has not been receptive to adopting these programs. Results from an analysis which links fire awareness, risk perceptions and policy preferences indicate that urban residents have a low initial awareness to fire severity, assign low probabilities to occurrences, and prefer policy strategies that shift the hazard management responsibility to public resource managers.

Fire Management in Coastal Sage-scrub, Southern California, USA

Wildland fire management directly affects the forces of natural selection to which plant taxa become adapted. Changes in a fire regime will often result in changes in the relative abundance of particular species, and may cause the extinction of some of them. Life-history characteristics are important indicators of adaptation to recurrent disturbance, such as may be produced by fire. The incorporation of these characteristics in a computer simulation allows of the projection of species abundance under different fire regimes.Through prescribed burning and fire suppression, fire interval and fire intensity can be controlled to some extent. The fire intensity for given sets of fuel, site, and meteoro-logical conditions, representing given fire-intervals, is calculated with the use of a fire behaviour computer simulation. These results are incorporated in computer simulation of the demographic competition of the five dominant shrub species of coastal sage-scrub in the Santa Monica Mountains of southern California:Artemisia californica, Encelia californica, Eriogonum cinereum, Salvia leucophylla, andS. mellifera. The model incorporates resprouting proportions, seedling establishment, and growth, and assumes survivorship rates in simulating scramble competition for space. Foliar cover-values of the five species are projected for nine different fire regimes. Short fire-intervals of the order of 10–20 years, such as might occur under a regime of prescribed burning, may eliminate or greatly reduce some species, whereas longer intervals allow the maintenance of a more diverse community especially of shrubs. Fixed and variable interval-lengths do not produce appreciably different results.This study suggests that prescribed burning at 10–20 years' intervals should not be used indiscriminately to reduce wildland fire hazard in southern California. The fire intervals that will reduce the hazard, may eliminate some dominant native shrub species. A ‘natural’ fire regime which would maintain the natural vegetation while constituting only a minimum hazard to homesites may, unfortunately, be mutually exclusive goals in the coastal sage-scrub of southern California.