The Effect Of The Growth Of The Wildland Urban Interface On Wildfire Occurrence Patterns In Arizona

The wildland urban interface (WUI) increases wildland fire suppression expenditures and impedes land managers' ability to reduce fire risk. Policies to reduce these WUI impacts are hindered by jurisdictional externalities -- federal agencies are charged with protecting homes from wildland fires, while local governments decide where and how development can occur. Policymakers therefore need an understanding of WUI characteristics that drive firefighting expenditures to develop effective solutions for existing and future WUI development. Despite a growing body of literature indicating that the spatial pattern of development impacts the efficiency and cost of public service provision, the effect of WUI development pattern on fire suppression expenditures has received only cursory treatment in the literature. I address this gap by empirically modeling the relationship between fire suppression expenditures and the spatial pattern of residential development. I use data on 280 fires in the Northern Rockies (CO, MT and WY) to estimate a regression model relating suppression expenditures to fire characteristics, management characteristics, and the spatial pattern of development. I find that the effect of WUI development on suppression expenditures is highly dependent on spatial pattern. Though past research has confirmed that the presence of structures influences expenditures, my results indicate that the effect of development on fire suppression expenditures cannot be accurately assessed without considering the spatial pattern of development. A unit increase in the complexity of development pattern increases expenditures by approximately six percent. The difference in expenditures between fires with dispersed or clustered structures can be as much as $620,000. My results indicate that policies that control the spatial pattern of WUI development can be nearly as effective as policies that completely restrict WUI development.

Flame and Fortune in the American West creatively and meticulously investigates the ongoing politics, folly, and avarice shaping the production of increasingly widespread yet dangerous suburban and exurban landscapes. The 1991 Oakland Hills Tunnel Fire is used as a starting point to better understand these complex social-environmental processes. The Tunnel Fire is the most destructive fire—in terms of structures lost—in California history. More than 3,000 residential structures burned and 25 lives were lost. Although this fire occurred in Oakland and Berkeley, others like it sear through landscapes in California and the American West that have experienced urban growth and development within areas historically prone to fire. Simon skillfully blends techniques from environmental history, political ecology, and science studies to closely examine the Tunnel Fire within a broader historical and spatial context of regional economic development and natural-resource management, such as the widespread planting of eucalyptus trees as an exotic lure for homeowners and the creation of hillside neighborhoods for tax revenue—decisions that produced communities with increased vulnerability to fire. Simon demonstrates how in Oakland a drive for affluence led to a state of vulnerability for rich and poor alike that has only been exacerbated by the rebuilding of neighborhoods after the fire. Despite these troubling trends, Flame and Fortune in the American West illustrates how many popular and scientific debates on fire limit the scope and efficacy of policy responses. These risky yet profitable developments (what the author refers to as the Incendiary), as well as proposed strategies for challenging them, are discussed in the context of urbanizing areas around the American West and hold global applicability within hazard-prone areas.

This text is an introduction to the study of towns and cities. The book synthesizes a wealth of material to provide a comprehensive introduction for students of urban geography, drawing on a rich blend of theoretical and empirical information, to advance their knowledge of the city. For the first time in the history of humankind, urban dwellers outnumber rural residents and this trend is destined to continue. Urban places, towns and cities are of fundamental importance: for the distribution of population within countries; in the organization of economic production, distribution and exchange; in the structuring of social reproduction and cultural life; and in the allocation and exercise of power. Even those living beyond the administrative or functional boundaries of a town or city, will have their lifestyle influenced to some degree by a nearby or distant city.

Wildfires in California play an important role in many ecosystems; however, when frequency rises, they can have deleterious effects on native flora and fauna. For humans living in vulnerable areas, wildfire can threaten the property and lives of residents. This is of particular concern for those living in the wildland-urban interface (WUI), where urban and open lands meet. Identifying areas making up the WUI and assessing fire risk is critical for proper land management. However, common definitions of these areas are quite general, often relying solely on a distance from housing structures to wildland vegetation or a threshold population density. In California, where wildfire occurrence has become prolific in recent years, the most recent effort to map high risk areas was carried out in the early '90s and has not been updated since. This study employed a method of WUI delineation developed by Lampin-Maillet et al. (2009) using housing density, vegetation aggregation, and terrain criteria to identify factors that contribute to wildfire risk (ignition density) and severity (burned area). In addition, classification of the interface area based on these factors allowed for an exploration of their interactions and the identification of areas that face particularly high wildfire risk or severity. This was done with the goal of determining where fire prevention resources and practices could be employed with the greatest benefit. It was determined that the WUI area in a subsection of Los Angeles County occupied 208,718 ha. Fire occurrence data including 1,802 fire ignition points and fire perimeters covering 139,178 ha were used to explore the relationship between fire risk and severity between classes of three risk factors. In addition 18 different WUI types were defined by combining classes of each risk factor to identify the combination of risk factors that results in the greatest wildfire risk or severity. It was found that housing density was the most important factor in determining wildfire risk, while slope was the most important in determining severity. Areas of intermediate housing density (1.2 houses/hectare) were at the greatest risk and experienced the greatest severity. Areas of high vegetation aggregation experienced the greatest severity, but the lowest risk. Finally, due to significantly high wildfire risk, the Castaic, Acton/Agua Dulce, and Leona Valley areas were identified as being ideal candidates for fire prevention programs focused on resident education and awareness. Given continued urban growth in Los Angeles County and the spread of urban development into wildland territory, this information will be critical to future decisions in urban planning and land management as well as to the direction of fire prevention resources.

It is essential to study the relationship between environmental features and human land-use activities that can provide a better understanding of human-environment interactions. In a response, this dissertation addresses the human-environment issues from different perspectives in three essays. The first essay conducts an integrated analysis to investigate the impacts of human activities and environmental features on wildfire occurrence at the Wildland-Urban Interface in a changing climate. We focus on the impacts of land use changes as measured by their density, connectivity, and mix. The conceptual model builds on a theoretical framework developed by Woodward (1987) and Neilson (1995) that characterizes the functioning mechanism of ecosystems. The empirical models identify the key factors that influence wildfires. Hypotheses are tested to demonstrate the spatial heterogeneity of human land-use impacts on wildfires. Results can inform the design of policies that aim to identify community vulnerabilities, reduce wildfire uncertainties, strengthen firewise community development, and inform future land-use decision making in response to wildfire threats. The second essay analyzes the impacts of wildfire risk on urban development. It builds on and expands the monocentric-city framework developed by Wu (2006) and Wu (2010) by introducing wildfire risk into this model. We calibrate the model and examine the urban spatial profiles changes under different assumptions of wildfire risks and natural amenities. We find that wildfire risk can take on various aspects of urban spatial profiles at a much broad scale that go beyond the fire-prone areas and affects both households and public decision sectors. Even without inconsistency in fire-zone designation policy, over-development can occur in fire-hazardous area. The third essay models the role of amenity in interregional migration and spatial distribution of economic activities. Extending the new economic geography model of Helpman (1998) by including locational amenities, we present a multi-market equilibrium framework that includes consumption, production, and trade. Results suggest that the effects of amenities are significantly affected by household preferences, trade barriers, and other regional economic characteristics. This study contributes to the amenity-driven migration literatures and informs the debate about the effect of amenities on interregional migrations and regional economic development.

A compilation and summary of four research studies is presented. They were aimed at developing a theoretical and practical understanding of homeowners' attitudes and behaviors in the wildland-urban interface (WUI) in relation to the threat from wildland fires. Individual studies focused on models and methods that measured (1) value orientations (patterns of basic beliefs) toward natural processes, (2) attitudes toward wildland fire policies, and (3) behavioral intentions to adopt defensible space activities or support agency policies/actions. This report presents some of the key findings from these studies, highlights the practical consequences of adopting a theory-based approach to understanding wildland fire management in urbanized areas, and suggests strategies for successful wildfire-prevention education programs.

A wildfire of variable severity swept through 717 acres (290 ha) of ponderosa pine forest in north-central Arizona in May 1972. Where the fire was intense it killed 90% of the small trees and 50% of the sawtimber, burned 2.6 in (6.5 cm) of forest floor to the mineral soil, and induced a water-repellent layer in the sandier soils. The reduced infiltration rates, which greatly increased water yield from severely burned areas during unusually heavy fall rains, caused soils to erode and removed some nutrients which had been mineralized by the fire. Water yields have declined each year toward prefire levels.