WUI state of the art and regulatory needs in Europe

The document summarizes the state of the art of the regulationsrelevant to WUI in Europe, providing an organized set of references to the specific regulatory documents. It is focused on three main relevant topics: i) fuel-reduced fringes; ii) Building codes and standards; iii)Wildland-Industrial Interface. Current regulations are analysed and compared, leading to the identification of important needs and limitations of the current European regulatory frameworkPreprin

San Diego, 2050 is Calling: How Will We Answer?

Recent public opinion surveys have found that an overwhelming majority -- 84% -- of San Diego County residents believe climate change is happening, and almost as many expect the impacts to affect them, their families and future generations. This report is meant to provide those who live, do business and govern in our region with up to date scientific understanding of how the impacts of climate change are likely to affect our region and how regional leaders are already responding to those impacts. Better understanding can help us, individually and collectively, decide which paths will define the kind of future we want to create. Information for this report was provided by a group of more than 40 multidisciplinary experts from local universities, governments, public sector agencies, nonprofits and private sector organizations throughout the San Diego region. Working together, these experts collected the most up to date science based on historical data and current trends, as well as complex models that project the various impacts of climate change expected in the region related to extreme weather events, water supply, wildfires, natural resources and public health

Estimating Private Incentives for Wildfire Risk Mitigation: Determinants of Demands for Different Fire-Safe Actions

In this article we develop a general conceptual model of a property-owner’s decision to implement actions to protect his property against wildfire threat. Assuming a prospective-utility maximizing decision maker, we derive a system of demand functions for fire-safe actions that characterizes factors affecting individual decision making. We then empirically estimate the demands for various fire-safe actions functions using survey data of property owners facing a wildfire threat in Nevada. We find that the probability of individuals implementing some fire-safe action increases with value of the residence, previous experience with wildfire, the property being used as the primary residence, positive attitude towards wildfire management methods on public lands, and connectedness of community members. A lower probability of implementing fire-safe actions is found for those who value pristine nature and privacy that nature provides.Risk and Uncertainty,

The relationship between well-being and wildfire

In this study, the well-being evaluation method, a technique for measuring individual utility, was used to study how people in the wildland urban interface of Colorado (USA) felt about their lives before and after two hypothetical wildfire scenarios. Variables such as age, family size, fire frequency, and property value were found to affect initial well-being levels. However, if a wildfire were to occur, many variables that initially affected well-being were no longer significant. It was found that after wildfire, the frequency of wildfire occurrence became the most important influence on well-being. These results have several implications for wildfire managers. First, the well-being of Colorado wildland urban interface residents would be enhanced by a reduction in the frequency of high-intensity wildfires. Secondly, an extremely high percentage of respondents were in favor of prescribed burning. Therefore, the reduction of high-intensity fires could not only be accomplished by conducting a rotation of prescribed fires, but that prescribed burning would be accepted by the public living in the wildland urban interface

Review of California Wildfire Evacuations from 2017 to 2019

Between 2017 and 2019, California experienced a series of devastating wildfires that together led over one million people to be ordered to evacuate. Due to the speed of many of these wildfires, residents across California found themselves in challenging evacuation situations, often at night and with little time to escape. These evacuations placed considerable stress on public resources and infrastructure for both transportation and sheltering. In the face of these clear challenges, transportation and emergency management agencies across California have widely varying levels of preparedness for major disasters, and nearly all agencies do not have the public resources to adequately and swiftly evacuate all populations in danger. To holistically address these challenges and bolster current disaster and evacuation planning, preparedness, and response in California, we summarize the evacuations of eleven major wildfires in California between 2017 and 2019 and offer a cross-comparison to highlight key similarities and differences. We present results of new empirical data we collected via an online survey of individuals impacted by: 1) the 2017 October Northern California Wildfires (n=79), 2) the 2017 December Southern California Wildfires (n=226), and 3) the 2018 Carr Wildfire (n=284). These data reveal the decision-making of individuals in these wildfires including choices related to evacuating or staying, departure timing, route, sheltering, destination, transportation mode, and reentry timing. We also present results related to communication and messaging, non-evacuee behavior, and opinion of government response. Using the summarized case studies and empirical evidence, we present a series of recommendations for agencies to prepare for, respond to, and recover from wildfires

Factors Leading to Structure Loss on the Thomas Fire

The recent surge in fire activity and the extent of displaced communities as a result of wildfire has increased awareness of wildfire issues nationwide (Syphard et al., 2017). Climate change, population growth, and continued development in the wildland urban interface (WUI) has contributed to a growing body of research into the underlying causes of this continued destruction (Kramer et al., 2019). There is no doubt that statewide policies, such as defensible space or building regulations, are associated with home survival (Keeley & Syphard, 2019). However, the relative effectiveness of wildfire mitigation depends on a myriad of factors specific to individual communities impacted by wildfire. This study focuses on factors that contributed to structure loss as a result of the 2017 Thomas Fire in Ventura, CA. Through spatial analysis utilizing GIS software, we were able to determine that defensible space played a minimal role in structural survivability during the Thomas Fire. Our research shows that fence type (noncombustible, combustible, or none) is a more significant factor at decreasing the odds of structure loss for homes experiencing wildfire under similar conditions. Effective wildfire mitigation relies on multiple factors, and government agencies must take a holistic approach rather than singular, “one size fits all” approaches to reduce the impact of future catastrophic wildfire

Socially Vulnerable Populations Experiences with Wildfire Preparation Programs at Lake Tahoe

Wildfires have been increasing in size and severity, with more people being impacted each year. To prepare communities, wildfire agencies and organizations across the United States are receiving significant public and private funding to expand the amount of information and support services they provide to community members, such as free defensible space inspections, public workshops, and print and online resources. Although wildfire itself does not discriminate against specific community members, wildfire agencies and organizations have failed to adapt existing programs to provide individualized support to socially vulnerable populations, including Spanish-speakers, older adults, and persons with disabilities, who are disproportionately impacted by wildfires each year. Lake Tahoe has experienced several large-scale wildfires in recent years, with the 2021 Caldor Fire having impacted communities significantly. This study seeks to identify how Lake Tahoe wildfire agencies and organizations can adapt their programs to prepare socially vulnerable populations for the inevitable impacts of wildfires

Integrated Framework for Wildfire Risk Mitigation Planning at the Wildland/Urban Interface

Past suppression-based wildfire management practices have increased the frequency and intensity of wildfires. Advocates for the re-introduction of natural wildfire regimes must also prioritize wildfire damage protection, especially for vulnerable communities located near forests. Areas where urban and forest lands interdigitate are called the Wildland Urban Interfaces (WUIs). In the United States, the area of the WUIs is increasing, making more people vulnerable to wildfires. By responding to four research objectives, this dissertation proposed and tested an integrated framework for wildfire risk mitigation decision making at WUIs. Decision makers who could benefit from the results of this dissertation include WUI homeowners, community planners, insurance companies, and agencies that provide financial resources for managing wildfire. The first objective investigated the complex relationship between wildfire and property values in a WUI community affected by a catastrophic wildfire event. The analysis focused on evaluating whether the damage from a previous wildfire, and the risk from a potential future wildfire are negatively capitalized in the housing market of a WUI community. A Hedonic Pricing Method (HPM) was applied on homes in Los Alamos County located in Northern New Mexico. Los Alamos is the home of a highly educated and high income community which experienced the Cerro Grande fire in 2000. Results showed that wildfire damage has a negative impact on the housing price, whereas future wildfire risk is a positive driver in the Los Alamos housing market. These findings support the wildfire mitigation paradox that states that WUI homeowners tend to underinvest for mitigating wildfire risk on their properties. The second objective investigated the optimal investment required for mitigating the vulnerability of residential buildings to wildfire. The optimal retrofit plan for individual homes was estimated using an integer programming method. The evaluation function for this optimization is based on a multi-attribute vulnerability assessment system that yields a wildfire vulnerability rating for all properties in the study area. A feasible solution to this optimization problem is one that decreases the vulnerability rating of the house to an acceptable rating. Additional data included: (i) vulnerability assessment cards of the properties, (ii) building and site characteristics of the properties, and (iii) unit costs of implanting appropriate retrofit measure on each element of the property. These datasets were collected for 389 properties in Santa Fe County’s WUIs. Using an integer programing model, the total cost of reducing the vulnerability ratings from “high” and “very high” to “moderate” vulnerability level was estimated for each property. To account for uncertainties in the costs of implementing a specific retrofit measure, a Monte-Carlo sampler was used to generate 2,400 cost scenarios from cost probability distributions. Using a regression analysis on the property data, a cost function for vulnerability mitigation through retrofitting was derived. The cost function allows estimation of the retrofitting cost per area of the house and considering the initial vulnerability rating of the house. The third objective was to investigate wildfire optimal mitigation investment schedules for homeowners. Two types of investments for mitigation were analyzed, namely self-insurance and market insurance. Self-insurance is represented financially as the amount homeowners spend to implement retrofit measures to reduce their property’s vulnerability to wildfires. Market insurance is the transfer of wildfire damage liability to a third party or insurance company. The investment decision of homeowners over a multi-year investment plan considering the effects of budget and market insurance policy constraints was formulated. The effectiveness of self-insurance improvements was modeled as a damage probability function. Using a mixed-integer programming model, the optimal annual investment for market and self-insurance was estimated. The case study in this chapter demonstrated the effect of various parameters on the investment schedule of honeowners. This case study considered the time value of money and insurance companies’ contingency policies and budget constraints. The results showed that in the absence of budget constraints and mandates on mitigation, the homeowner’s optimal choice would be to fully invest on insurance and to purchase the broadest wildfire hazard insurance coverage. When a minimum mitigating retrofit effort is required by insurance companies, homeowners would invest more at the beginning of the period and decrease their investment through time. In this case results showed that a homeowner would achieve a higher expected value of investment than a homeowner with whose investments increase through time. In the fourth objective, an Agent Based Model (ABM) is proposed to account for heterogeneity in homeowners’ attributes and behaviors when confronting wildfire risk hazard. The success of the community to reduce wildfire risk was evaluated by aggregating the impact of each individual agent’s behavior. The investment behavior of each homeowner for a five-year planning period was retrieved from the optimization model proposed in the third objective. A neighborhood of six homeowners was used to test the proposed ABM. When a wildfire occurs, the wildfire may or may not damage the property. Therefore, the loss accrued by each homeowner was stochastically simulated for each year in the simulation. The probability of loss was formulated as a function of the initial vulnerability rating of the property and the homeowners’ cumulative investment on mitigation. The analyzed scenarios considered different types of homeowners (i.e. mitigating or non-mitigating). The spatial impact of neighboring properties on the loss potential of a homeowner was modeled using a conceptual fire spread model based on a Cellular Automata propagation model. Results suggest that (i) the location of the property in combination with (ii) the investment behavior of the homeowner influences the neighborhood’s aggregate loss to wildfire. Policy-makers can better mitigate aggregate loss to wildfire by prioritizing certain locations over others

Mapping values at risk, assessing building loss and evaluating stakeholder expectations of wildfire mitigation in the wildland-urban interface

2020 Fall.Includes bibliographical references.The Wildland-Urban Interface (WUI) is an area where residential development extends into undeveloped land. When WUI development occurs in hazard-prone fire-adapted ecosystems, wildfires can have detrimental impacts on human communities by destroying buildings and infrastructure. Wildfires that cause substantial building loss are known as WUI disasters because of their high social and economic costs. WUI disasters tend to occur when wildfires ignite under extreme burning conditions and threaten a large number of homes in hazardous conditions relative to firefighting resources. This combination of factors can lead to significant home loss. WUI disasters annually result in billions of dollars in fire suppression costs and destroy thousands of homes Governments, land managers, and effected stakeholders respond to this threat in numerous ways as they attempt to mitigate the impacts of wildfires and reduce losses in WUI communities. Although wildfire mitigation efforts emphasize the removal of nearby flammable vegetation and the use of nonflammable building materials, one of the critical steps involves developing a map of communities and buildings at risk in the WUI. Despite broad-scale mapping efforts, most WUI maps do not identify building locations at sufficiently fine scales to estimate fire exposure and inform wildfire planning. Defensible space is promoted as the most effective way to reduce home ignition; however, questions remain surrounding its interactions with fire response, and its efficacy under the wide range of potential fire behavior to which homes could be exposed. This dissertation sought to realize three goals: first, it examined the potential of new technologies to map the WUI and the buildings within it at fine scales; second, it evaluated how well existing WUI mapping efforts capture the pattern of building loss observed during WUI disasters; and third, it examined stakeholder perspectives on the efficacy and interactions of defensible space and fire response with regards to protecting homes from WUI disasters. Chapter two evaluates the ability of Object Based Image Analysis to extract WUI building locations from orthoimagery of the wildland-urban interface by testing accuracy and error at multiple scales. I found the approach can extract building locations with high rates of accuracy, and minimal user input. Extracting building locations using this approach can lead to comprehensive datasets of building locations in the WUI, which can be used to create more detailed maps of buildings exposed to wildfires. Such maps have utility for risk mapping, fuel treatment prioritization, and incident management, and can lead to a better understanding regarding the spatial patterns of home loss. Chapter three leverages building location data to quantify the impacts of WUI disasters and evaluate the accuracy of WUI maps. I compare how well existing polygon-based SILVIS WUI maps and point-based WUI maps capture the pattern of building loss and assess building loss in relation to the core components of the WUI definition. Findings can be used to improve existing WUI maps, create point-based WUI maps from building location datasets, identify which homes are most in need of defensible space, and refine risk mapping and identification of wildfire exposure zones. Finally, chapter four assesses stakeholder perspectives regarding the efficacy of defensible space and its interactions with fire response with regards to the stakeholders' ability to protect homes from WUI disasters. This is related to the prior mapping efforts because it speaks to the ways stakeholders co-manage wildfire risk with fire protection authorities, and the actions they take to protect threatened homes mapped using the methods evaluated in chapters one and two. These qualitative methods suggest a wide range in expectations of defensible space efficacy, both in theory and in practice. It is likely that numerous factors reduce the perceived and actual efficacy of defensible space