Fire Spread Simulation Modeling to Assess Wildfire Hazard and Exposure to Communities in Northern Iran

The impacts of wildfires have been increasing in the Mediterranean Basin, and Portugal recently experienced some of the most extreme fire seasons on record. It is urgent to shift wildfire management goals by re-balancing wildfire suppression and mitigation efforts, to reduce fire intensity and increase the effectiveness of suppression operations. Our study aims at assessing wildfire hazard in Serra da Cabreira (NW Portugal) by combining landscape-scale wildfire modelling and landscape wildfire connectivity analysis. The impact of two levels of landscape treatment in wildfire hazard decrease was also assessed. We used the 95th percentile historical weather conditions (2001–2019) to simulate fireline intensity (FLI), burn probability (BP) and fire size (FS), using the Minimum Travel Time (MTT) algorithm implemented in FlamMap (Vers.6). We calculated wildfire connectivity using the simulated FLI to: (1) guide the choice of the area of the landscape to be treated; and (2) identify the relative importance of single fuel patches to overall landscape connectivity. Results showed that significant decreases in BP (36%), FS (39%), FLI (61%) and wildfire connectivity (48%) were obtained when 20% of the landscape was treated. For the same treatment level, the median FLI decreases to values below 2000 kW/m, with likely areas to burn at high intensity decreasing by 4.4%. We also estimated ca. 15% decrease in the area with fires larger than 1000 ha. We discuss the results and highlight the relevance of integrating wildfire connectivity into wildfire hazard assessment, to support landscape fuel management plans aiming at decreasing fire intensity and thus the mitigation of its impacts.

Wildfire exposure and risk in pulp paper companies’ plantations under extreme weather conditions: A case study in North-Western Portugal

The occurrence of wildfires within municipal watersheds can result in significant impacts to water quality and ultimately human health and safety. In this paper, we illustrate the application of geospatial analysis and burn probability modeling to assess the exposure of municipal watersheds to wildfire. Our assessment of wildfire exposure consists of two primary components: (1) wildfire hazard, which we characterize with burn probability, fireline intensity, and a composite index, and (2) geospatial intersection of watershed polygons with spatially resolved wildfire hazard metrics. This effort enhances investigation into spatial patterns of fire occurrence and behavior and enables quantitative comparisons of exposure across watersheds on the basis of a novel, integrated measure of wildfire hazard. As a case study, we consider the municipal watersheds located on the Beaverhead-Deerlodge National Forest (BDNF) in Montana, United States. We present simulation results to highlight exposure across watersheds and generally demonstrate vast differences in fire likelihood, fire behavior, and expected area burned among the analyzed municipal watersheds. We describe how this information can be incorporated into risk-based strategic fuels management planning and across the broader wildfire management spectrum. To conclude, we discuss strengths and limitations of our approach and offer potential future expansions.

Fuel fragmentation and fire size distributions in managed and unmanaged boreal forests in the province of Saskatchewan, Canada

We analysed the spatiotemporal patterns of wildfire likelihood and intensity in the Ardabil Province, NW Iran. Wildfire simulation modelling based on the minimum travel time (MTT) fire spread algorithm (Finney 2002) was applied to estimate the fire occurrence, size, flame length, and burn probability in the area within the study period (2005–2018). To inform wildfire simulations, we gathered fuel types, fire weather conditions, and topography input data. Historical hourly wind and weather data for the study period were obtained from the Ardabil weather station. Moreover, we obtained historical ignition data from the Ardabil Natural Resources Department and FRWO, Iran. On average, about 97 ignitions per year were observed in the study area. According to the simulations, the burn probability, conditional flame length, and fire size ranged from 0.0003 to 0.01, 0 to 6.75 m, and 0 to 5200 ha, respectively. The highest values of the simulations, and consequently the largest and most severe wildfires, occurred in July, especially in the southern and northern portions of the province. The simulation outputs were consistent with historical fire frequency and current knowledge about fire patterns within the study area. The methodology proposed in this study provides a valuable contribution to the improvement of fuel management and wildfire risk mitigation strategies, adjusted to the specific wildfire conditions of different areas.

Examining management scenarios to mitigate wildfire hazard to caribou conservation projects using burn probability modeling

Climate change effects on wildfire hazards in the wildland-urban-interface – Blue pine forests of Bhutan

Abstract
 In many countries, small ruminants provide the primary source of human protein and play an important role in livestock production. Parasitic infections, especially gastrointestinal parasites, cause economic losses such as reduced fertility and milk production, damage to the leather industry, weight loss, treatment costs, and losses in severe infections. Thus, identifying and classifying these parasites, including the above cases, is essential for scientific research in any country. This study aimed to Prevalence of Abomasum Nematode infection in Sheep from North of Iran. In the present cross-sectional descriptive study, we have studied the prevalence of infection with abomasum nematodes in sheep in northern Iran from April 2020 to September 2021 in 2400 abomasum sheep slaughtered in industrial slaughterhouses in Gilan and Mazandaran provinces (1200 sheep from each province). With three age groups of below two years, two to four years, and above four years and gender segregation of hosts, after necropsy and preparation of sheep abomasal mucosa chip and isolation and segregation of samples, we studied the morphologic and morphometric characteristics of the samples. The actions were performed according to the taxonomic keys and using SPSS software V.16 and Paired Sample T-Test statistical test to determine the level of significance of the data (p <0.05) to classify and compare the obtained data and examine the ratio. The sex of the host was determined by the age of the animal and the prevalence of the parasite at the mentioned ages. The present study results and comparison of the prevalence of infection in Gilan and Mazandaran provinces showed that Marshallagia marshalli had the highest prevalence of 94.6% and 91.9% in Mazandaran and Gilan province, respectively. The prevalence of Ostertagia circumcincta was 87.2% and 77.2% in Gilan and Mazandaran provinces. The prevalence of Ostertagia occidentalis was 86.9% in Gilan province and 78% in Mazandaran province, while the prevalence of Parabronema skrjabini was 86.6% in Gilan province and 61.2% in Mazandaran province. The prevalence of Haemonchus contortus was 66.8% and 60.5% in Gilan and Mazandaran, the lowest prevalence in these two provinces. The present study results showed the importance of combating the spread of parasitic infections with strategic treatment methods and biological control of these parasites. Also, various reports of drug resistance in abomasal nematodes should be emphasized more and more by competent bodies.
 Keywords: Abomasum, Nematodes, North of Iran, Parasitic infections, Sheep.

In Mediterranean agropastoral areas, land abandonment is a key driver of wildfire risk as fuel load and continuity increase. To gain insights into the potential impacts of land abandonment on wildfire risk in fire-prone areas, a fire-spread modeling approach to evaluate the variations in wildfire potential induced by different spatial patterns and percentages of land abandonment was applied. The study was carried out in a 1200 km2 agropastoral area located in north-western Sardinia (Italy) mostly covered by herbaceous fuels. We compared nine land abandonment scenarios, which consisted of the control conditions (NA) and eight scenarios obtained by combining four intensity levels (10, 20, 30, 40%) and two spatial patterns of agropastoral land abandonment. The abandonment scenarios hypothesized a variation in dead fuel load and fuel depth within abandoned polygons with respect to the control conditions. For each abandonment scenario, wildfire hazard and likelihood at the landscape scale was assessed by simulating over 17,000 wildfire seasons using the minimum travel time (MTT) fire spread algorithm. Wildfire simulations replicated the weather conditions associated with the largest fires observed in the study area and were run at 40 m resolution, consistent with the input files. Our results highlighted that growing amounts of land abandonment substantially increased burn probability, high flame length probability and fire size at the landscape level. Considering a given percentage of abandonment, the two spatial patterns of abandonment generated spatial variations in wildfire hazard and likelihood, but at the landscape scale the average values were not significantly different. The average annual area burned increased from about 2400 ha of the control conditions to about 3100 ha with 40% land abandonment. The findings of this work demonstrate that a progressive abandonment of agropastoral lands can lead to severe modifications in potential wildfire spread and behavior in Mediterranean areas, thus promoting the likelihood of large and fast-spreading events. Wildfire spread modeling approaches allow us to estimate the potential risks posed by future wildfires to rural communities, ecosystems and anthropic values in the context of land abandonment, and to adopt and optimize smart prevention and planning strategies to mitigate these threats.

Adding fuel to the fire? Revegetation influences wildfire size and intensity

Abstract. Fire exposure describes the spatial juxtaposition of values with fire behaviour in terms of likelihood and intensity. Wildfire exposure analysis is based on the estimation of the potential wildfire intensity and on the burn probability. Fire modelling can produce spatially explicit information on fire spread and behaviour, and offers a feasible method to simulate, map, and analyse fire exposure. FlamMap Minimum Travel Time (MTT) algorithm (Finney, 2006) was used to conduct wildfire simulations considering historical data of fuel moisture conditions and winds, as well as the most frequent wind directions and historical ignition locations (2005-2018). Analysis was conducted on spatial and quantitative variations in selected fire hazard and exposure factors, namely Burn Probability (BP), Conditional Flame Length (CFL) and Fire Size (F). We observed pronounced spatial variations among and between municipalities in the factors, especially for those in the northern and southern parts of Ardabil. The variations across the burnable area of the municipalities can be fundamentally related to a number of factors, including spatial variation in ignition locations, fuel moisture and load, weather conditions, and topography of the terrain. The findings can provide information and support in wildfire management planning and fire risk mitigation activities.

Burn probability simulation and subsequent wildland fire activity in Alberta, Canada – Implications for risk assessment and strategic planning

We used simulation modelling to analyse spatial variation in wildfire exposure relative to key social and economic features on the island of Sardinia, Italy. Sardinia contains a high density of urban interfaces, recreational values and highly valued agricultural areas that are increasingly being threatened by severe wildfires. Historical fire data and wildfire simulations were used to estimate burn probabilities, flame length and fire size. We examined how these risk factors varied among and within highly valued features located on the island. Estimates of burn probability excluding non-burnable fuels, ranged from 0–1.92 × 10–3, with a mean value of 6.48 × 10–5. Spatial patterns in modelled outputs were strongly related to fuel loadings, although topographic and other influences were apparent. Wide variation was observed among the land parcels for all the key values, providing a quantitative approach to inform wildfire risk management activities.

BackgroundPrescribed burning (PB) is becoming relevant in fuel reduction and thus fire hazard abatement in fire-prone ecosystems of southern Europe. Yet, empirical evidence on the effectiveness of this practice to mitigate wildfire severity in Mediterranean shrublands is non-existent, despite being the focus of PB efforts in this region. Here, we intended to quantify the protective effect of PB treatment units (2005–2021) to subsequent wildfire severity in shrublands across mainland Portugal, as well as the relative contribution and complex interactions between drivers of wildfire severity in PB-treated areas and untreated neighboring counterparts through Random Forest regression. We leveraged cloud-computing remote sensing data processing in Google Earth Engine to estimate fire severity (PB and wildfire) as the Relativized Burn Ratio (RBR) using Landsat data catalog.ResultsPB treatment was particularly effective at mitigating wildfire severity at the first PB-wildfire encounter in shrublands, with a mean reduction of around 24% in RBR units. Fuel age (i.e., time since prescribed burning) in PB-wildfire intersection areas overwhelmed to a large extent the effect of fire weather, burning probability, and PB severity. The mitigating effect of PB on wildfire severity persisted for a fuel age of around 5 years. However, this effect decreased with increasingly adverse fire weather conditions, such that variation in wildfire severity was somewhat insensitive to fuel age under extreme fire weather. Similarly, the lowest wildfire severity experienced in sites with high burning probability, along with the interaction effect observed between burning probability and fuel age, suggest that repeated PB treatments may be useful in controlling fuel accumulation and mitigating wildfire severity. The relative contribution of fire weather in explaining wildfire severity was exceedingly high in untreated areas, doubling that of the other variables in the model in the absence of PB treatment variables.ConclusionsOur results suggest that the implementation of PB treatments at intervals of less than 5 years is of paramount importance to control fuel build-up and fire hazard under extreme fire weather in productive Mediterranean shrublands. Further research on this topic is warranted in other shrublands worldwide, namely in Mediterranean-type climate regions.

Wildfire simulation is deployed extensively to support risk management, and in the US has driven billions in federal investment. Foundational to strategic risk analysis is spatial information on the likelihood of burning in a fire year, typically provided by burn probability (BP) models. The recency of BP maps is a key driver of their accuracy, especially in disturbed landscapes that have experienced changes in fire spread potential. Few published examples exist comparing BP values against subsequent fire activity, and none to our knowledge evaluate annually updated BP maps. Here, we present a novel performance evaluation of the operational wildfire simulation system FSim, confronting updated BP maps with subsequent fire activity across the state of California over a 4-year period (2020–2023). Results show strong predictive ability: across 5 equal-area BP classes, 56.7–79.8% of the burned area occurred in the top 20% of mapped area; mean (median) BP values in burned areas were 238.5–348.8% (551.4–880.7%) greater than in unburned areas; differences in empirical cumulative distribution functions of BP for burned/unburned areas were statistically significant; Logarithmic Skill Scores ranged from − 0.072 to 0.389 against two reference models. Findings indicate reliable forecast performance and useful application of up-to-date BP maps, critical to support ongoing wildfire risk mitigation.