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Author Alvarez, C.; Moreno, G.; Valenzuela, F.; Rivera, J.I.; Ebensperger, F.; Reszka, P.; Fuentes, A.
Title Use of an electric heater as an idealized firebrand to determine ignition delay time of Eucalyptus globulus leaves Type
Year 2023 Publication Fire Safety Journal Abbreviated Journal Fire Saf. J.
Volume 141 Issue Pages 103923
Keywords Wildfires; Spotting fires; Thermal model
Abstract The Idealized-Firebrand Ignition Test (I-FIT) protocol was used to evaluate the piloted ignition delay times of fuel beds composed of leaves of Eucalyptus globulus (Labill.). The amount of fuel layer used for evaluation ranged between the fraction volume (������) of 0.03 to 0.07 which are values expected to be found in forest bed fuels. A theoretical model was developed to describe the heating and ignition of the fuel beds, based on the thermal ignition theory. The model, which was originally developed for pine needle beds, considers the penetration of radiation to the porous matrix. The model is able to accurately predict the ignition delay time for different values of ������, but shows a poorer accuracy for the temperature evolution. This is explained by the large variability observed for the Eucalyptus leaves.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0379-7112 ISBN Medium
Area Expedition Conference
Notes WOS:001072435400001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1889
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Author Arevalo-Ramirez, TA.; Castillo, AHF.; Cabello, PSR.; Cheein, FAA.
Title Single bands leaf reflectance prediction based on fuel moisture content for forestry applications Type
Year 2021 Publication Biosystems Engineering Abbreviated Journal Biosyst. Eng.
Volume 202 Issue Pages 79-95
Keywords Leaf water index; Machine learning; Remote sensing; Wildfire; Wildland fuels
Abstract Vegetation indices can be used to perform quantitative and qualitative assessment of vegetation cover. These indices exploit the reflectance features of leaves to predict their biophysical properties. In general, there are different vegetation indices capable of describing the same biophysical parameter. For instance, vegetation water content can be inferred from at least sixteen vegetation indices, where each one uses the reflectance of leaves in different spectral bands. Therefore, if the leaf moisture content, a vegetation index and the reflectance at the wavelengths to compute the vegetation index are known, then the reflectance in other spectral bands can be computed with a bounded error. The current work proposes a method to predict, by a machine learning regressor, the leaf reflectance (spectral signature) at specific spectral bands using the information of leaf moisture content and a single vegetation index of two tree species (Pinus radiata, and Eucalyptus globulus), which constitute 97.5% of the Valparai ' so forests in Chile. Results suggest that the most suitable vegetation index to predict the spectral signature is the Leaf Water Index, which using a Kernel Ridge Regressor achieved the best prediction results, with an RMSE lower than 0.022, and an average R2 greater than 0.95 for Pinus radiata and 0.81 for Eucalyptus globulus, respectively. (c) 2020 IAgrE. Published by Elsevier Ltd. All rights reserved.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1537-5110 ISBN Medium
Area Expedition Conference
Notes WOS:000613400300008 Approved
Call Number UAI @ alexi.delcanto @ Serial 1346
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Author Baselli, G.; Contreras, F.; Lillo, M.; Marin, M.; Carrasco, R.A.
Title Optimal decisions for salvage logging after wildfires Type
Year 2020 Publication Omega-International Journal Of Management Science Abbreviated Journal Omega-Int. J. Manage. Sci.
Volume 96 Issue Pages 9 pp
Keywords Salvage logging; Forest harvesting; Wildfires; Workforce allocation
Abstract Strategic, tactical, and operational harvesting plans for the forestry and logging industry have been widely studied for more than 60 years. Many different settings and specific constraints due to legal, environmental, and operational requirements have been modeled, improving the performance of the harvesting process significantly. During the summer of 2017, Chile suffered from the most massive wildfires in its history, affecting almost half a million hectares, of which nearly half were forests owned by medium and small forestry companies. Some of the stands were burned by intense crown fires, which always spread fast, that burned the foliage and outer layer of the bark but left standing dead trees that could be salvage harvested before insect and decay processes rendered them unusable for commercial purposes. Unlike the typical operational programming models studied in the past, in this setting, companies can make insurance claims on part or all of the burnt forest, whereas the rest of the forest needs to be harvested before it loses its value. This problem is known as the salvage logging problem. The issue also has an important social component when considering medium and small forestry and logging companies: most of their personnel come from local communities, which have already been affected by the fires. Harvesting part of the remaining forest can allow them to keep their jobs longer and, hopefully, leave the company in a better financial situation if the harvesting areas are correctly selected. In this work, we present a novel mixed-integer optimization-based approach to support salvage logging decisions, which helps in the configuration of an operational-level harvesting and workforce assignment plan. Our model takes into account the payment from an insurance claim as well as future income from harvesting the remaining trees. The model also computes an optimal assignment of personnel to the different activities required. The objective is to improve the cash position of the company by the end of the harvest and ensure that the company is paying all its liabilities and maintaining personnel. We show how our model performs compared to the current decisions made by medium and small-sized forestry companies, and we study the specific case of a small forestry company located in Cauquenes, Chile, which used our model to decide its course of action. (C) 2019 Elsevier Ltd. All rights reserved.
Address [Baselli, Gianluca; Contreras, Felipe; Lillo, Matias; Marin, Magdalena; Carrasco, Rodrigo A.] Univ Adolfo Ibanez, Fac Engn & Sci, Santiago, Chile, Email: gbaselli@alumnos.uai.cl;
Corporate Author Thesis
Publisher Pergamon-Elsevier Science Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0305-0483 ISBN Medium
Area Expedition Conference
Notes WOS:000541944700003 Approved
Call Number UAI @ eduardo.moreno @ Serial 1186
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Author Gonzalez, M.E.; Galleguillos, M.; Lopatin, J.; Leal, C.; Becerra-Rodas, C.; Lara, A.; San Martin, J.
Title Surviving in a hostile landscape: Nothofagus alessandrii remnant forests threatened by mega-fires and exotic pine invasion in the coastal range of central Chile Type
Year 2022 Publication Oryx Abbreviated Journal Oryx
Volume Early Access Issue Pages
Keywords Chile; Endangered species; exotic invasion; Nothofagus alessandrii; Pinus radiata; wildfire
Abstract Nothofagus alessandrii, categorized as Endangered on the IUCN Red List, is an endemic, deciduous tree species of the coastal range of central Chile. We assessed the effects of fire severity, invasion by the exotic fire-prone Pinus radiata, and land-cover composition and configuration of the landscape on the resilience of fragments of N. alessandrii after a mega-fire in 2017. We used remote sensing data to estimate land-use classes and cover, fire severity and invasion cover of P. radiata. We monitored forest composition and structure and post-fire responses of N. alessandrii forests in situ for 2 years after the mega-fire. In the coastal Maule region wildfires have been favoured by intense drought and widespread exotic pine plantations, increasing the ability of fire-adapted invasive species to colonize native forest remnants. Over 85% of N. alessandrii forests were moderately or severely burnt. The propagation and severity of fire was probably amplified by the exotic pines located along the edges of, or inside, the N. alessandrii fragments and the highly flammable pine plantations surrounding these fragments (> 60% of land use is pine plantations). Pinus radiata, a fire-adapted pioneer species, showed strong post-fire recruitment within the N. alessandrii fragments, especially those severely burnt. Positive feedback between climate change (i.e. droughts and heat waves), wildfires and pine invasions is driving N. alessandrii forests into an undesirable and probably irreversible state (i.e. a landscape trap). A large-scale restoration programme to design a diverse and less flammable landscape is needed to avoid the loss of these highly threatened forest ecosystems.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0030-6053 ISBN Medium
Area Expedition Conference
Notes WOS:000871219600001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1666
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Author Miranda, A.; Mentler, R.; Moletto-Lobos, I.; Alfaro, G.; Aliaga, L.; Balbontin, D.; Barraza, M.; Baumbach, S.; Calderon, P.; Cardenas, F.; Castillo, I.; Contreras, G.; de la Barra, F.; Galleguillos, M.; Gonzalez, M.E.; Hormazabal, C.; Lara, A.; Mancilla, I.; Munoz, F.; Oyarce, C.; Pantoja, F.; Ramirez, R.; Urrutia, V.
Title The Landscape Fire Scars Database: mapping historical burned area and fire severity in Chile Type
Year 2022 Publication Earth System Science Data Abbreviated Journal Earth Syst. Sci. Data
Volume 14 Issue 8 Pages 3599-3613
Keywords TIME-SERIES; LAND-USE; ALGORITHM; WILDFIRES; IMPACTS; RDNBR
Abstract Achieving a local understanding of fire regimes requires high-resolution, systematic and dynamic databases. High-quality information can help to transform evidence into decision-making in the context of rapidly changing landscapes, particularly considering that geographical and temporal patterns of fire regimes and their trends vary locally over time. Global fire scar products at low spatial resolutions are available, but high-resolution wildfire data, especially for developing countries, are still lacking. Taking advantage of the Google Earth Engine (GEE) big-data analysis platform, we developed a flexible workflow to reconstruct individual burned areas and derive fire severity estimates for all reported fires. We tested our approach for historical wild-fires in Chile. The result is the Landscape Fire Scars Database, a detailed and dynamic database that reconstructs 8153 fires scars, representing 66.6% of the country's officially recorded fires between 1985 and 2018. For each fire event, the database contains the following information: (i) the Landsat mosaic of pre- and post-fire images; (ii) the fire scar in binary format; (iii) the remotely sensed estimated fire indexes (the normalized burned ratio, NBR, and the relative delta normalized burn ratio, RdNBR); and two vector files indicating (iv) the fire scar perimeter and (v) the fire scar severity reclassification, respectively. The Landscape Fire Scars Database for Chile and GEE script (JavaScript) are publicly available. The framework developed for the database can be applied anywhere in the world, with the only requirement being its adaptation to local factors such as data availability, fire regimes, land cover or land cover dynamics, vegetation recovery, and cloud cover. The Landscape Fire Scars Database for Chile is publicly available in https://doi.org/10.1594/PANGAEA.941127 (Miranda et al., 2022).
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1866-3508 ISBN Medium
Area Expedition Conference
Notes WOS:000838024900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1667
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Author Thomsen, M.; Fernandez-Pello, A.C.; Williams, F.A.
Title On the Growth of Wildland Fires from a Small Ignition Source Type
Year 2023 Publication Combustion Science and Technology Abbreviated Journal Combust. Sci. Technol.
Volume Early Access Issue Pages
Keywords Wildfire; spot ignition; fire growth; rate of spread; fire model
Abstract Wildland and Wildland-Urban-Interface (WUI) fires are an important problem that may have major consequences in terms of safety, air quality, and damage to buildings, infrastructure, and the ecosystem. It is expected that with climate change, the wildland fire and WUI fire problem will only intensify. Wildland fires are often initiated by small ignition sources caused either by human intervention (hot metal fragments or burning biomass) or by natural events (lighting or sun heating). Once the wildfire or structural fire has been ignited and grows, it can spread rapidly through ember spotting, where pieces of burning materials are lifted by the plume of the fire and then transported forward by the wind, landing where they can start spot fires downwind. The ignition mechanisms for all of these fires have the common characteristic of a small and localized area of origin, with the subsequent spread of the fire to wider and larger areas. Because of the three-dimensional characteristics of this type of propagating fire, its rate of spread has an initial acceleration phase leading to an equilibrium rate of spread when the fire reaches a certain size, which is referred to as a “line-fire” type of spread. Most of the studies on wildland fire propagation have been conducted with line fires and have been concerned with characterizing the equilibrium rate of spread rather than the initial spread from a small ignition source. In this paper, some of the studies conducted to date on the subject of wildland fire growth from a small ignition source, and the physics supporting the mathematical expressions that are used to describe the growth of the fire are discussed. An attempt is also made to provide support for these works through a more fundamental approach to model the problem.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0010-2202 ISBN Medium
Area Expedition Conference
Notes WOS:001034393700001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1845
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Author Tolorza, V.; Poblete-Caballero, D.; Banda, D.; Little, C.; Leal, C.; Galleguillos, M.
Title An operational method for mapping the composition of post-fire litter Type
Year 2022 Publication Remote Sensing Letters Abbreviated Journal Remote Sens. Lett.
Volume 13 Issue 5 Pages 511-521
Keywords SOIL; BIODIVERSITY; WILDFIREI; MPACTS; CHILE
Abstract Recent increase in the frequency and spatial extent of wildfires motivates the quick recognition of the affected soil properties over large areas. Digital Soil Mapping is a valuable approach to map soil attributes based on remote sensing and field observations. We predicted the spatial distribution of post-fire litter composition in a 40,600 ha basin burned on the 2017 wildfire of Chile. Remotely sensed data of topography, vegetation structure and spectral indices (SI) were used as predictors of random forest (RF) models. Litter sampled in 60 hillslopes after the fire provided training and validation data. Predictors selected by the Variable Selection Using Random Forests (VSURF) algorithm resulted in models for litter composition with acceptable accuracy (coefficient of determination, R (2) = 0.51-0.64, Normalized Root Mean Square Error, NRMSE = 16.9-22.1, percentage bias, pbias = -0.35%-0.5%). Modelled litter parameters decrease in concentration respect to the degree of burn severity, and the pre-fire biomass. Because pre-fire vegetation was conditioned by land cover and by a previous (2 years old) wildfire event, our results highlight the cumulative effect of severe wildfires in the depletion of litter composition.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2150-704X ISBN Medium
Area Expedition Conference
Notes WOS:000763106200001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1547
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Author Valenzuela, F.; Rivera, J.I.; Ebensperger, F.; Alvarez, C.; Reszka, P.; Auat Cheein, F.; Fuentes, A.
Title Ignition of Wildland Fuels Exposed to a Time-Decreasing Incident Heat Flux Type
Year 2023 Publication Combustion Science and Technology Abbreviated Journal Combust. Sci. Technol.
Volume 195 Issue 14 Pages 3596-3611
Keywords Wildfires; Spotting fires; Thermal model; Firebrand
Abstract The effect of decreasing incident heat fluxes on the ignition delay time of dry pine needles is addressed in the present study. A customized modular instrument (I-FIT) that uses radiant heaters to simulate idealized firebrands ensures experimental repeatability for combustion experiments. Linear incident heat flux ramps are obtained by controlling the power of the heating element, thus simulating idealized firebrands. An analytical model based on the thermal ignition theory was developed and solved analytically using an integral approach. This model includes convective losses and in-depth penetration of radiation. Radiation was modeled using the P1 approximation. The theoretical model is complemented and validated by experimental data, showing increments of the ignition delay times when the negative slope steepness over time increases for the same heat flux. For given values of the initial incident heat flux on the sample, a critical slope beta(cri) is observed. For slopes steeper than this critical value, ignition is not attained.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0010-2202 ISBN Medium
Area Expedition Conference
Notes WOS:001044563300001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1865
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