Wildland Urban Interface Areas Research Articles

Predicting conditional maximum contaminant level exceedance probabilities for drinking water after wildfires with Bayesian regularized network ensembles

The severity and frequency of wildfires have increased throughout the Pacific Northwest in recent decades, costing lives and destroying large amounts of valuable resources and assets. This trend is predicted to persist because of climate change and the associated increased fire risk caused by prolonged droughts in combination with changes in land cover and land use, including rapid increases in wildland urban interface areas. The threat of benzene and other contaminants in drinking water from water distribution systems after wildfires is a relatively recently discovered problem that gained attention because of the significant health hazards that high levels of benzene in drinking water pose for humans. Driving processes leading to post-fire benzene contamination in water distribution systems are largely unknown. Currently, no deterministic process models exist to predict the risk of exceeded benzene levels in water distribution systems after wildfires. To address the lack of predictive models, we developed and tested an approach based on neural network models to spatially predict the conditional probabilities of exceeding maximum contaminant levels for benzene after wildfires. The Bayesian regularized neural networks were trained using high-resolution data layers comprising topography, soil properties, landcover, vegetation, meteorological parameters, fuel load, and infrastructure data for two wildland urban interface areas in northern California. The generalized model ensemble encompassing data from both communities exhibits an accuracy of 83% to 88% in spatially predicting the post-fire exceedance of benzene levels, offering a planning tool for emergency response and future risk mitigation efforts.

Homeowners willingness to pay to reduce wildfire risk in wildland urban interface areas: Implications for targeting financial incentives

This study estimated homeowner's willingness to pay for public and private fuel reduction programs in wildland urban interface areas using a choice experiment implemented in California. A multinomial logit (MNL) model was estimated and indicated that homeowners living in subjectively perceived high-risk areas would pay for new wildfire risk mitigation programs. This suggests the importance of risk perceptions in adoption of risk mitigation behavior. Prior research has indicated that demographic factors influence risk perceptions. Therefore, the heterogeneity of homeowner preferences regarding wildfire risk perceptions and mitigation behavior, not explicitly revealed in the basic MNL model, was investigated using Latent Class (LC) and Random Parameter Latent Class (RPLC) models. Results from the LC model indicated that homeowners with lower income/education levels are more likely to ignore risk factors in making wildfire mitigation decisions, and generally prefer the status quo to paying the costs of new wildfire risk mitigation programs. Similar results were found in the RPLC model, except for gender is no longer significant. These results suggest that many low income/education level homeowners in the study area will require accessible and persuasive information on wildfire risk as well as significant financial incentives to undertake private wildfire risk mitigation efforts on their property and to support broader public efforts to protect communities. In contrast, many higher income/education households are more sensitive to risk factors when making wildfire mitigation decisions and would pay a substantial amount for public and private programs, making the existing cost share approach for these types of households workable.

Parallel Implementation of the Algorithm to Compute Forest Fire Impact on Infrastructure Facilities of JSC Russian Railways

Forest fires have a negative impact on the economy in a number of regions, especially in Wildland Urban Interface (WUI) areas. An important link in the fight against fires in WUI areas is the development of information and computer systems for predicting the fire safety of infrastructural facilities of Russian Railways. In this work, a numerical study of heat transfer processes in the enclosing structure of a wooden building near the forest fire front was carried out using the technology of parallel computing. The novelty of the development is explained by the creation of its own program code, which is planned to be put into operation either in the Information System for Remote Monitoring of Forest Fires ISDM-Rosleskhoz, or in the information and computing system of JSC Russian Railways. In the Russian Federation, it is forbidden to use foreign systems in the security services of industrial facilities. The implementation of the deterministic model of heat transfer in the enclosing structure with the complexity of the algorithm O (2N2 + 2K) is presented. The program is implemented in Python 3.x using the NumPy and Concurrent libraries. Calculations were carried out on a multiprocessor cluster in the Sirius University of Science and Technology. The results of calculations and the acceleration coefficient for operating modes for 1, 2, 4, 8, 16, 32, 48 and 64 processes are presented. The developed algorithm can be applied to assess the fire safety of infrastructure facilities of Russian Railways. The main merit of the new development should be noted, which is explained by the ability to use large computational domains with a large number of computational grid nodes in space and time. The use of caching intermediate data in files made it possible to distribute a large number of computational nodes among the processors of a computing multiprocessor system. However, one should also note a drawback; namely, a decrease in the acceleration of computational operations with a large number of involved nodes of a multiprocessor computing system, which is explained by the write and read cycles in cache files.

Trends in Fire Danger and Population Exposure along the Wildland–Urban Interface

The increased risk of wildfires and associated smoke exposure in the United States is a growing public health problem, particularly along the Wildland-Urban Interface (WUI). Using the measure of fire danger, the Energy Release Component, we define fire danger as the onset and duration of fire season, in the continental US, between 1979 and 2016. We then combine the measure of fire danger with census data to quantify changes in population fire exposure across the WUI. We determined that the largest increases in fire danger were observed in the Southwest, Intermountain, and Pacific Southwest regions. The increased fire danger, specifically during peak fire season, accounted for 6.1 more fires each year and 78,000 more acres burned each year, underscoring the link between fire danger and the risks of large fire occurrence and burn acreage. Finally, we observed significant population growth (121.2% between 1990 and 2010) within high-danger WUI areas, further implying significant increases in potential fire exposure.

Growth of the wildland-urban interface within and around U.S. National Forests and Grasslands, 1990–2010

The wildland-urban interface (WUI), where housing is in close proximity to or intermingled with wildland vegetation, is widespread throughout the United States, but it is unclear how this type of housing development affects public lands. We used a national dataset to examine WUI distribution and growth (1990–2010) in proximity to National Forests and created a typology to characterize each National Forest’s combination of WUI area and housing growth. We found that National Forests are hotspots for WUI growth, with a 38% increase in WUI area and 46% growth in WUI houses from 1990 to 2010, in excess of WUI growth for the conterminous U.S. Growth within National Forests was higher than the surrounding area. Diffuse intermix WUI, where houses are intermingled with wildland vegetation, is common within National Forests, but WUI houses around National Forests were primarily in denser interface WUI areas, which lack substantial wildland vegetation. WUI was more prevalent within and around National Forests in the East, while National Forests in the West experienced higher rates of WUI growth. National Forests with the most challenging WUI issues—extensive WUI area and rapid growth in intermix and interface—were found primarily in the South and interior West. Given the diversity of WUI landscapes, effectively responding to current and future WUI challenges will require both engagement with individual homeowners dispersed throughout National Forests, as well as increased emphasis on mitigating denser interface development around National Forests. At a time when wildfire risks are expected to intensify due to climate change, and 75% of privately owned land within and around National Forests is not yet WUI, understanding WUI growth patterns in proximity to public lands is vital for land management and human well-being.

A Comparative Analysis of Two Major Approaches for Mapping the Wildland-Urban Interface: A Case Study in California

The Wildland Urban Interface (WUI) is where human settlements border or intermingle with undeveloped land, often with multiple detrimental consequences. Therefore, mapping the WUI is required in order to identify areas-at-risk. There are two main WUI mapping methods, the point-based approach and the zonal approach. Both differ in data requirements and may produce considerably different maps, yet they were never compared before. My objective was to systematically compare the point-based and the zonal-based WUI maps of California, and to test the efficacy of a new database of building locations in the context of WUI mapping. I assessed the spatial accuracy of the building database, and then compared the spatial patterns of WUI maps by estimating the effect of multiple ancillary variables on the amount of agreement between maps. I found that the building database is highly accurate and is suitable for WUI mapping. The point-based approach estimated a consistently larger WUI area across California compared to the zonal approach. The spatial correspondence between maps was low-to-moderate, and was significantly affected by building numbers and by their spatial arrangement. The discrepancy between WUI maps suggests that they are not directly comparable within and across landscapes, and that each WUI map should serve a distinct practical purpose.

Characterization of Firebrands Released From Different Burning Tree Species

The number, dimensions, and initial velocity of the firebrands released from burning Quercus suber, Eucalyptus globulus, Quercus robur, and Pinus pinaster trees were analyzed in laboratory experiments using a particle image velocimetry system. Additionally, the flame height, tree mass decay, vertical flow velocity, and temperature at the top of the trees were measured during the experiments. The relationship between the various parameters was analyzed and a good connection was found. The specimens burnt were mostly young trees, so large particles (e.g., pine cones, thick trunk barks, branches) were not included in this study as they were not present. Actually, the firebrands produced in the laboratory tests, mainly burning leaves, had a cross-sectional area of <1,600 mm2, having the potential to cause short distance spotting (up to tens of meters). Quercus trees are often considered to have a lower fire risk than eucalyptus or pine trees. However, in this study, Quercus suber and Quercus robur were the species that produced more firebrands, both in terms of number and total volume. The tests with Quercus suber were the only ones using specimens from an adult tree, confirming the great importance of the age of trees in the propensity to release firebrands. The results obtained with Quercus robur confirmed the high tendency of this species to originate spot fires at a short distance. Thus, these results are of great relevance to afforestation plans and to evaluating the risk of the presence of these species in wildland–urban interface areas.

Open data repositories and Geo Small Data for mapping the wildfire risk exposure in wildland urban interface (WUI) in Spain: A case study in the Valencian Region

The risk of forest fires in areas of wildland urban-interface (WUI.) is increasing due to the increase in urbanized areas and the progressive abandonment of traditional farming and forest uses. The global increase in catastrophic episodes in regions with a Mediterranean climate is worrying. Resilient towns and villages have given way to extensive and scattered residential estates that are in contact with forest fuel. These changes in the landscape when added to those of the climate, increase the danger of what some call ‘igneous storms’. The risk in many areas has increased greatly in the last few decades. It is necessary to limit the growing exposure to this type of risk – and geographical information resources are essential for determining the territorial magnitude of the problem. Official libraries offering remote sensing data or geographical databases on land use and land cover (LULC) may be the best option (although accessing this data is complex for many end users). This research proposes identifying areas exposed to fire risk in the wildland-urban interface (WUI) through the automated integration of massive data from official geographic information sources. The application of this study to the region of Valencia (Spain) shows that the integration of these official sources of geographical information can achieve the objective at a detailed scale with relatively short processing times and for large geographical areas (approximately 8 h required to process about 70 Gb of LIDAR data). Geo Small Data techniques for the process of large datasets and its application to the objective of the study have been the best way to automate the analysis of lidar point clouds, with more than 5 billion echoes, through the use of free and open tools, containerization technologies, parallel processing and specific python libraries for geospatial data management. The LIDAR data has provided the necessary geometric definition to complement and improve the WUI area map from the reclassification of hundreds of thousands of polygons from the official Spanish land use geodatabase (SIOSE), achieving a map scale of more than 1: 25,000, for its part, the quality of the SIOSE geodatabase has allowed us to reduce the total LIDAR data to process by 97.8%.

Building Extraction and Number Statistics in WUI Areas Based on UNet Structure and Ensemble Learning

Following the advancement and progression of urbanization, management problems of the wildland–urban interface (WUI) have become increasingly serious. WUI regional governance issues involve many factors including climate, humanities, etc., and have attracted attention and research from all walks of life. Building research plays a vital part in the WUI area. Building location is closely related with the planning and management of the WUI area, and the number of buildings is related to the rescue arrangement. There are two major methods to obtain this building information: one is to obtain them from relevant agencies, which is slow and lacks timeliness, while the other approach is to extract them from high-resolution remote sensing images, which is relatively inexpensive and offers improved timeliness. Inspired by the recent successful application of deep learning, in this paper, we propose a method for extracting building information from high-resolution remote sensing images based on deep learning, which is combined with ensemble learning to extract the building location. Further, we use the idea of image anomaly detection to estimate the number of buildings. After verification on two datasets, we obtain superior semantic segmentation results and achieve better building contour extraction and number estimation.

FLAMMABILITY OF ORNAMENTAL SPECIES FOR FIRE MANAGEMENT IN WILDLAND-URBAN INTERFACE IN PARANÁ STATE

The objective of this work was to evaluate the flammability of ornamental species as a tool for fire management in areas of wildland-urban interface in Paraná. For this, native ornamental species and exotic species were selected. Initially, the following morphological characteristics of the leaves, which are associated with the flammability of the selected species were evaluated: texture, exudates, hairiness and enervation. The flammability characteristics of the species were analyzed through burning experiments. Fifty 1g burns of freshly harvested plant material of each species were conducted in an epiradiator. The variables collected were: ignition frequency (FI), time to ignition (TI), combustion duration (DC) and combustion index (CI). These variables were statistically analyzed by the SNK test at 95% probability. The Cluster test was also performed to identify different levels of flammability of the species tested as a function of the morphological characteristics and the flammability parameters obtained in the epiradiator tests. The results showed that FI and TI were lower in most native species (except Verbena rigida ), differing statistically from exotic ones. There were differences among the species as a function of the species leaf morphology and the flammability parameters measured during the burning. It can be inferred that most native species may have been considered slightly flammable and exotic as flammable, with the exception of the species Euonymus japonica , classified as zero flammability, concluding that native species are the most suitable for use in fire management in wildland-urban interface areas in Paraná, and should be intensively used in landscaping.

LES Simulation of Wind-Driven Wildfire Interaction with Idealized Structures in the Wildland-Urban Interface

This paper presents a numerical investigation of the impact of a wind-driven surface fire, comparable to a large wildfire, on an obstacle located downstream of the fire source. The numerical modelling was conducted using FireFOAM, a coupled fire-atmosphere model underpinned by a large eddy simulation (LES) solver, which is based on the Eddy Dissipation Concept (EDC) combustion model and implemented in the OpenFOAM platform (an open source CFD tool). The numerical data were validated using the aerodynamic measurements of a full-scale building model in the absence of fire effects. The results highlighted the physical phenomena contributing to the fire spread pattern and its thermal impact on the building. In addition, frequency analysis of the surface temperature fluctuations ahead of the fire front showed that the presence of a building influences the growth and formation of buoyant instabilities, which directly affect the behaviour of the fire’s plume. The coupled fire-atmosphere modelling presented here constitutes a fundamental step towards better understanding the behaviour and potential impacts of large wind-driven wildland fires in wildland-urban interface (WUI) areas.

Integrating wildfire risk management and spatial planning – A historical review of two Australian planning systems

Recent wildfires burning throughout Australia highlight the vulnerability of settlements located in wildland urban interface (WUI) areas. Spatial planning has a critical role in operationalising wildfire risk reduction considerations in a territorial manner across the WUI. Accordingly, more integrated approaches to wildfire management and spatial planning are necessary. However, there is limited literature examining the historical interactions between wildfire and spatial planning policy sectors and how institutions and policy instruments adapt over time to integrate mutually dependent considerations. To address this gap, this research examines how Australian spatial planning institutions and instruments evolved since European settlement to incorporate wildfire considerations, through a qualitative comparative case study approach of two Australian states. Based on the findings of the case study comparison, this paper presents a conceptual framework of the pathways towards increased policy integration of spatial planning and wildfire risk reduction that consists of six phases. It is argued that the path to greater policy integration is grounded on the development of common knowledge, a cross-disciplinary understanding, and agreed policy goals between different policy sectors, that, with time, translate into new institutional arrangements and instruments that integrate the work and decision-making processes of different sectors.

Modelling of wildland-urban interface fire spread with the heterogeneous cellular automata model

Fire safety in urban areas is gaining more attention along with the rapid development of urbanization and the increasing complexity of urban structures. Many fire spread models have been developed to support emergency decision making. However, most of them only investigate on single scenarios (forest fire or house fire) and usually have difficulty in balancing model accuracy and timeliness, which makes it hard to apply these models to large-scale heterogeneous scenarios. In this paper, we developed a fire spread model based on the heterogeneous Cellular Automata model for large-scale complex wildland-urban interface (WUI) areas. The model flexibly integrates a forest fire model and a house fire model based on thermal principles and empirical statistics. A software platform is developed based on the fire spread model correspondingly to validate its performance. Taking a real WUI fire occurred in California as a case study, we conducted comparative simulation experiments based on our software platform and widely used forest fire simulation software FlamMap6. The experimental results show that our model can simulate fire spread process with high efficiency, strong timeliness, and competitive accuracy, providing support on emergency decision-making of large-scale complex fire scenarios.

Zoneamento de incêndios florestais na estação ecológica Águas Emendadas, Distrito Federal (Brasil)

O aumento no número de ocorrências de incêndios florestais no bioma Cerrado é considerado uma ameaça à sua conservação. Dessa forma, as áreas protegidas por meio das Unidades de Conservação (UC) são fundamentais para a proteção dos biomas brasileiros. No entanto, mesmo essas áreas são acometidas por incêndios que comprometem suas integridades. Neste sentido, este estudo teve como objetivo elaborar o zoneamento do risco de incêndio florestal da UC Estação Ecológica Águas Emendadas por meio do método multicritério aditivo, validá-lo com as cicatrizes dos incêndios ocorridos entre os anos de 2011 a 2015 e avaliar a espacialidade do risco a incêndios florestais. Foi observado que nenhuma área da UC estudada foi classificada como zona de risco Extremo, no entanto mais de 60% da UC foi classificada em zonas de Alto ou Muito Alto risco a incêndios. A validação mostrou que 80% dos incêndios ocorreram sobre áreas com risco mediano a incêndios florestais como formações savânicas ou campestres. Foi obtido um Índice Global de Moran para o risco de incêndios florestais no valor de 0.83 indicando uma elevada autorrelação espacial, além disso, o Índice Local de Moran identificou como regiões mais críticas as áreas de interface de vegetação nativa e áreas urbanas.

Urban expansion into native forests in Patagonia, Argentina: assessing stakeholders’ perceptions regarding spatial planning

Argentina’s Native Forests Protection Act No. 26,331 (NFPA) enforces the use of spatial planning to regulate land use in native forests. However, guidelines regarding the spatial planning of native forests in urban and wildland-urban interface (WUI) areas are lacking. Taking the city of Ushuaia as a case study, we used a mixed-methods approach (online survey, individual interviews, and focus groups) to assess stakeholders’ perceptions regarding native forest land use planning in urban and WUI areas. Results revealed that regulations addressing native forest land use in urban and WUI areas are lacking but considered important. Communication between stakeholders, public participatory processes, and current forest zoning criteria were identified as challenging aspects of native forest policy. Among the strategies to address these challenges, stakeholders emphasized developing: new opportunities for stakeholder communication, mechanisms for community engagement, specific guidelines for native forest land use planning in urban and WUI areas, and dissemination and education.

Vulnerability of peri‑urban and residential areas to landscape fires in Greece: Evidence by wildland-urban interface data

We provide a map of wildland urban interface (WUI) areas at national scale in Greece, using as primary data the Corine Land Cover (CLC) 2018 product. The WUI areas distribution in Greece is calculated for all the regional units of the county. The regional units correspond to NUTS (Nomenclature of Territorial Units for Statistics) level 2 for Greece, being important for the national to regional fire risk management and mitigation within the country. Furthermore, spatially explicit information regarding the fire affected areas and the changes in WUI areas between 2006 and 2018 on the basis of the CLC data for each regional unit is also provided.This geospatial information can provide valuable, concurrent information at no-cost to all responsible and competent authorities involved in landscape fire management in Greece and represent a valuable contribution to assist in national and regional scale planning.

Mapping the Wildland-Urban Interfaces for Forest Fire Prevention in the Province of Mila (Algeria)

Areas where the habitat is in contact with the forest represent danger and become a real concern for managers who need location tools to act and limit fire risks in these territories. In this context, our study focuses on determining and mapping the different types of wildland-urban interface (WUI) existing in the Zouagha forest. The methodology integrates four types of a housing structure, limited to a radius of 100 meters around each house and three classes of vegetation aggregation. The GIS tool maps and identifies twelve types of WUI in the study area. Our results show that WUI areas in the Zouagha forest increased rapidly over the last decade. New houses were the main cause for new WUI. In 2019, the number of buildings in the study area was 51% higher than in 2009. These urban areas are more exposed to wildfire risks due to their proximity to flammable fuels. The spatial analysis allows highlighting the WUI type most sensitive to a fire risk that needs the interventions of environment protection institutions to limit the damage of wildfires.

An examination of the social-psychological drivers of homeowner wildfire mitigation

Wildfire events have been impacting many parts of the United States. Of particular importance are the Wildland-Urban Interface (WUI) areas, where residential development exposes residents to increased risk from the threat of wildfire. However, evidence shows that WUI homeowners do not adequately mitigate risk through participation in programs such as Firewise USA®. In this investigation, we examined social-psychological factors that influence homeowners' intentions to adopt Firewise activities. Data were collected from a random sample of 1633 households in three wildfire-prone WUI areas of southern California. Structural equation modeling results illustrated that homeowners' perceived effectiveness of Firewise activities, along with their perceived risk of wildfire, significantly influenced their intentions to adopt suggested activities. We also found that respondents' past experience with wildfire and home attachment increased their intentions to adopt Firewise activities. Furthermore, the congruence between agency's and individuals' values (i.e., salient value similarity) increased homeowners' trust in agency management and information, and, subsequently, their perceptions of the effectiveness of wildfire risk mitigation activities. Alternately, past experience with wildfire diminished trust in agencies responsible for wildland fire mitigation. Our findings shed light on the ambiguities surrounding the role of past experience, risk perception, and place attachment in hazard preparedness. In addition to risk communication and promoting action effectiveness, our findings illustrate the importance of integrating cognitive heuristics and emotional bonds along with existing rational, evaluative models of decision-making to encourage homeowners' wildfire risk mitigation behavior.

My Place or Yours? Using Spatial Frames to Understand the Role of Place in Forest Management Conflicts

Vegetation treatment projects in wildland urban interface (WUI) areas are highly visible to public scrutiny, which can lead to stakeholder conflicts (e.g. land managers, public) that block a treatment’s implementation, and possibly expose residents to wildfire risk. This study proposes that research on environmental conflicts should account for physical spaces. We develop a conceptualization of spatial frames by combining theorizing on conflict frames and place attachment. The empirical case tracks the re-implementation of Forsythe, a US Forest Service vegetation treatment project in Colorado. Data include public meeting observation (N = 11), and interviews and focus groups with N = 31 residents. The findings about spatial frames illustrate that physical landscapes inscribe retrospective memories of past activities, and prospective aspirations for future actions. The temporal orientation of spatial frames (i.e., retrospective, prospective) configures frame repertoires in particular ways to heighten intractability. Land manager recommendations provide forward-looking opportunities for stakeholder engagement.

Resistance and Representation in a Wildland–Urban Interface Fuels Treatment Conflict: The Case of the Forsythe II Project in the Arapaho-Roosevelt National Forest

Land treatments in wildland–urban interface (WUI) areas are highly visible and subject to public scrutiny and possible opposition. This study examines a contested vegetation treatment—Forsythe II—in a WUI area of the Arapaho-Roosevelt National Forest in Colorado. An initial phase of the research found vocal opposition to Forsythe II. The purpose of the present study was to understand how well the resistance narrative represented the broader community in the WUI area affected by the Forsythe II treatments. More than one third (36%) of households responded to a census survey focused on Forsythe II, demographics, wildfire risk perceptions, and variables associated with generic land management activities and place attachment. Overall, while public opposition to Forsythe II has resulted in a nearly 25% reduction in the project’s size, the survey data demonstrate that just over a quarter of respondents (27%) opposed or strongly opposed the Forsythe II project, and the majority of survey respondents reported broad support for forest management approaches similar to those detailed in the project plans. Notably, a similar portion (28%) did not report an opinion on the project. Results include a systematic comparison of opinion/no opinion respondents.