Treesearch

Smoke caused by wildland fire events is an important public health issue, involving major risks to the health of people and the environment. Smoke from wildland fires can travel hundreds of kilometers, affecting air quality far from the flames. Through a partnership with Health Canada, Manitoba Health's Office of Disaster Management (ODM) has undertaken a number of multi-year projects to improve our understanding of some of the aspects of these scientific and social issues related to wildland fire smoke. Through these projects, ODM will meet the following objectives: 1) develop specific...

Despite increasing proportions of governmental budgets allocated to fire suppression resources, wildfires annually destroy great numbers of homes and critical infrastructure in the wildland-urban interface (WUI). Since 2002, the largest fires in the histories of California, Arizona, Colorado, New Mexico, Utah, Oregon, and Texas have occurred in spite of increased fire agency staffing, equipment, and training (National Interagency Fire Center 2013). To aid policy development that reduces these losses, we propose to evaluate how risk changes through time in communities expanding into...

The increasing occurrence and extent of large-scale wildfires in the Mediterranean have been linked to extended periods of warm and dry weather. We set out to assess Lebanon's wildfire potential in association with current and future climatic conditions. The Keetch-Byram Drought Index (KBDI) was the primary climate variable used in our evaluation of climate/fire interactions and conditions. A comparison between the average monthly values (2006-2010) of the Fire Weather Index (FWI) for Eastern Mediterranean and the monthly KBDI average values for Lebanon showed a strong correlation,...

Hazardous fuel reduction treatments conducted both through prescribed fire and mechanical means are a critical part of the mitigation of wildland fire risk in the United States. The US Federal Government has spent an average of $500t million each year on fuel reduction, from 2002-2012 (Gorte 2011). At present, however, rigorous experimental measurement of the effectiveness of such efforts, as they impact wildfire intensity and spread rate, has been limited. The project presented here is aimed at addressing this knowledge gap by taking a combined experimental and numerical modeling approach...

Wall-to-wall remotely sensed data are increasingly available to monitor landscape dynamics over large geographic areas. However, statistical monitoring programs that use post-stratification cannot fully utilize those sensor data. The Kalman filter (KF) is an alternative statistical estimator. I develop a new KF algorithm that is numerically robust with large numbers of study variables and auxiliary sensor variables. A National Forest Inventory (NFI) illustrates application within an official statistics program. Practical recommendations regarding remote sensing and statistical issues are...

Long-term trends in forest attributes are typically assessed using strategic inventories such as the US Department of Agriculture (USDA) Forest Service’s Forest Inventory and Analysis (FIA) program. The implicit assumption of any trend analysis is that data are comparable over time. The 1998 Farm Bill tasked FIA with implementing nationally consistent protocols, including a spatially and temporally balanced sample design, whereas previous inventory methods varied spatially and temporally. To disentangle the artifacts of changing inventory designs from real forest change, this study...

Theory suggests that natural fire regimes can result in landscapes that are both self-regulating and resilient to fire. For example, because fires consume fuel, they may create barriers to the spread of future fires, thereby regulating fire size. Top-down controls such as weather, however, can weaken this effect. While empirical examples demonstrating this pattern-process feedback between vegetation and fire exist, they have been geographically limited or did not consider the influence of time between fires and weather. The availability of remotely sensed data identifying fire activity...

Land use legacies and climate have altered fire regimes across montane forests of much of the southwestern US (Allen and others 2002), and several recent wildfires have been extremely large and severe (Dennison and others 2014). Large openings resulting from high-severity fire in former ponderosa pine (Pinus ponderosa) and mixed conifer forests may be persistent given the lack of sufficient tree seed sources, climatic constraints on reproduction and survival, and competition from herbaceous and shrubby vegetation (Bonnet and others 2005; Haire and McGarigal 2010). Additionally, subsequent...

How well can we expect to predict the spread rate of wildfires and prescribed fires? The degree of accuracy in model predictions of wildland fire behaviour characteristics are dependent on the model's applicability to a given situation, the validity of the model's relationships, and the reliability of the model input data (Alexander and Cruz 2013b#. We examined the error statistics associated with 13 operational wildland fire rate of spread models developed in Australia and North America #see Cruz and Alexander 2013, Table 1#. We used 49 fire spread model evaluation datasets comprising...

The objective of the present study is twofold. First, the last developments and validation results of a hybrid model designed to simulate fire patterns in heterogeneous landscapes are presented. The model combines the features of a stochastic small-world network model with those of a deterministic semi-physical model of the interaction between burning and non-burning cells that strongly depends on local conditions of wind, topography, and vegetation. Radiation and convection from the flaming zone, and ambient radiative heat loss are considered in the preheating process of unburned cells....