Houses & WUI

The hazards-of-place model posits that vulnerability to environmental hazards depends on both biophysica and social factors. Biophysical factors determine where wildfire potential is elevated, whereas social factors determin where and how people are affected by wildfire. We evaluated place vulnerability to wildfire hazards in the coterminou US. We developed a social vulnerability index using principal component analysis and evaluated it against existin measures of wildfire potential and wildland–urban interface designations. We created maps showing the coincidence o social vulnerability and wildfire potential to identify places according to their vulnerability to wildfire. We found tha places with high wildfire potential have, on average, lower social vulnerability than other places, but nearly 10% of al housing in places with high wildfire potential also exhibits high social vulnerability. We summarised our data by states t evaluate trends at a subnational level. Although some regions, such as the South-east, had more housing in places with hig wildfire vulnerability, other regions, such as the upper Midwest, exhibited higher rates of vulnerability than expected. Ou results can help to inform wildfire prevention, mitigation and recovery planning, as well as reduce wildfire hazard affecting vulnerable places and populations.

One challenge in the effort to conserve biodiversity is identifying where to prioritize resources for active land management. Cost–benefit analyses have been used successfully as a conservation tool to identify sites that provide the greatest conservation benefit per unit cost. Our goal was to apply cost–benefit analysis to the question of how to prioritize land management efforts, in our case the application of prescribed fire to natural landscapes in Wisconsin, USA. We quantified and mapped frequently burned communities and prioritized management units based on a suite of indices that captured ecological benefits, management effort, and the feasibility of successful long- term manage-ment actions. Data for these indices came from LANDFIRE, Wisconsin’s Wildlife Action Plan, and a nationwide wildland–urban interface assessment. We found that the majority of frequently burned vegetation types occurred in the southern portion of the state. How-ever, the highest priority areas for applying prescribed fire occurred in the central, north-west, and northeast portion of the state where frequently burned vegetation patches were larger and where identified areas of high biological importance area occurred. Although our focus was on the use of prescribed fire in Wisconsin, our methods can be adapted to prioritize other land management activities. Such prioritization is necessary to achieve the greatest possible benefits from limited funding for land management actions, and our results show that it is feasible at scales that are relevant for land management decisions.

Following the loss of homes to wildfire, when risk has been made apparent, homeowners must decide whethe to rebuild, and choose materials and vegetation, while local governments guide recovery and rebuilding. As wildfires ar smaller and more localised than other disasters, it is unclear if recovery after wildfire results in policy change and adaptation decreasing assets at risk, or if recovery encourages reinvestment in hazard-prone areas. We studied three wildfires on th Colorado Front Range from 2010 to 2012 that each destroyed over 150 homes, describing policy response and characterisin the built environment after wildfire. In each location, we found some adaptation, through better-mitigated homes an stronger building and vegetation mitigation standards, but also extensive reinvestment in hazard-prone environments, wit governmental support. Despite suggestions that disaster can lead to substantial policy change and elevate the role of land-us planning, we saw only modest reforms: local governments did not revise land-use regulations; a statewide task forc considered but did not require standards for building and vegetation mitigation; and only one jurisdiction strengthened it building and vegetation mitigation standards. Experiences in Colorado suggest that time after wildfire either does no provide extensive opportunities for adaptation in the built environment, or that these opportunities are easily missed.

Context Wildfires destroy thousands of building every year in the wildland urban interface. However fire typically only destroys a fraction of the building within a given fire perimeter, suggesting more coul be done to mitigate risk if we understood how t configure residential landscapes so that both peopl and buildings could survive fire Objectives Our goal was to understand the relativ importance of vegetation, topography and spatia arrangement of buildings on building loss, within th fire’s landscape context Methods We analyzed two fires: one in San Diego CA and another in Boulder, CO. We analyzed Googl Earth historical imagery to digitize buildings expose to the fires, a geographic information system t measure some of the explanatory variables, an FRAGSTATS to quantify landscape metrics. Usin logistic regression we conducted an exhaustive mode search to select the best models Results The type of variables that were importan varied across communities. We found complex spatia effects and no single model explained building los everywhere, but topography and the spatial arrangemen of buildings explained most of the variability i building losses. Vegetation connectivity was mor important than vegetation type Conclusions Location and spatial arrangement o buildings affect which buildings burn in a wildfire which is important for urban planning, building siting landscape design of future development, and to target fire prevention, fuel reduction, and homeowner educatio efforts in existing communities. Landscap context of buildings and communities is an importan aspect of building loss, and if taken into consideration could help communities adapt to fire.