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Title: D3.1-2a Review of knowledge gaps and proposal for fuel data collection and test runs /
Language: English
Description: A review of the different aspects of fuel moisture research was conducted. The following knowledge (research) gaps can be identified: (a) The horizontal spatial variability of dead fuel moisture in relation to vegetation (e.g., stand structure, crown closure, stem density, litter and duff depth, etc.) and topographic characteristics (aspect, slope, soil depth and type, etc.) needs to be measured and modelled in the field. (b) The temporal (diurnal and seasonal) variation in dead and live fuel moisture content as related to changes in meteorological parameters (air relative humidity and temperature, insolation and cloudiness, wind speed and duration, etc) needs to be measured in the field for all the dominant Mediterranean fuel types at the species level, to the extent possible. For fire-stricken geographical regions of the Mediterranean Basin, extensive data bases of seasonal fuel moisture data per species or fuel type must be created and, subsequently, converted through statistical analysis to empirical models of fuel moisture prediction, refined for every species or fuel complex. (c) Equilibrium moisture content (EMC) sorption (adsorption and desorption) curves of dead fuels as a function of air relative humidity and temperature need to be created for the fuels of all the dominant species. (d) The fuel moisture timelag (TL) concept needs to be reassessed and measured in dead fuels from different species in relation to the fuel moisture sorption phase (adsorption or desorption), in order to account for the moisture hysteretic effects of dead fuels during the wetting or drying process. (e) A physical model that predicts canopy (crown) live fuel moisture content variations in terms of stand and tree phenological and physiological characteristics and soil water balance has to be formulated. (f) A comparison between actual measurements of dead fuel moisture with the moisture content of fuel analogues (i.e., fuel moisture sticks) is necessary in order to validate the precision of the analogues in fuel moisture assessment. (g) The relationship between dead and live fuel moisture and drought (prolonged period of high temperatures and low air and soil humidity) needs to be further investigated, and in particular, the response of shrub and tree species moisture content to drought. The use of the newly formed SPI (Standard Precipitation Index) drought index might be useful in the correlation with fuel moisture, in addition to the traditionally used KBDI and Palmer indexes. In view of the expected global warming and climatic change, this research aspect of fuel moisture could be very significant in the future. (h) The moisture of extinction (ME) of dead and live fuels must be measured in the field (in situ) with a long series of ignition experiments in different fuel types and, subsequently, correlated with the existing fuel moisture content and meteorological parameters in the field, into regression and probabilistic models. ME values of the most significant Mediterranean fuel types must be measured in the laboratory and in the field. (i) The condensation (water vapour that originates from the atmosphere in the form of dew on the surface of dead fuels) and the latent heat of vaporisation of free water from the fuel particle surface are two terms that are currently neglected and must be taken into account in future physical models of dead fuel moisture content. (j) The optimal temporal (time) step for monitoring vegetation moisture content (greenness) via satellite imagery needs to be determined in dead and live Mediterranean fuel complexes.
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Title: D3.1-5 Probability of ignition modelling in forest fuels – First results /
Language: English
Description: Following a similar approach to previous research, and aiming to cover gaps in the literature on ignition, especially in regard to Mediterranean conditions, the present study focuses on the following: (1) To evaluate the threshold of fuel moisture content that allows a fire to start. A range of fuel types (pine needles, grass and Quercus coccifera leaves) are examined, as are different ignition sources (kitchen matches, cigarettes, machinery sparks and electrical discharge), with the presence/absence of wind in order to determine the probability of ignition of selected natural dead fuels (MAICh); and (2) To measure the probability of ignition of annual live herbaceous fuels, at various moisture contents, in the field (AUTh). Fuel moisture content (FMC) is used as the main predictor variable throughout these experiments because it has a major effect on fuel ignitability, is easily altered and can be accurately measured. Only the first results of the study are presented within this deliverable: (1) Probability of ignition of pine needles (Pinus halepensis) with kitchen matches and cigarettes as ignition sources conducted in the wind tunnel of MAICh. (2) Probability of ignition of grass (Hyparrhenia hirta) with kitchen matches as an ignition source conducted in the wind tunnel of MAICh. (3) Some preliminary test of pine needles with machinery sparks as well as grass with cigarettes conducted in the wind tunnel of MAICh. (4) Fuel moisture extinction in live annual herbaceous plants (Avena barbata) in the field (AUTh). The final results will be presented within deliverable D 3.1-10 due in month 46 of the project.
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Title: Deliverable D3.1-12 Empirical modelling of fuel flammability and initial fuel propagation, including determination of fuel moisture threshold for fire ignition /
Language: English
Description: This report sums up the fuel flammability experiments (WP 3.1) dedicated to the determination of the thresholds of fuel moisture for fire ignition, and to the assessment of the ignition probability for different dead (i.e. litter) forest fuels in Greece, Spain, Argentina, and France. The probability of ignition has been modelled in for forest fuels through laboratory fires (Cemagref, INIA-CIFOR, MAICh, AUTH and CIEFAP), using different sources of ignitions and different environmental conditions (i.e. nul wind versus windy conditions). The sources of ignition were glowing, flaming, or sparks. The wind was controlled and set as nul or strong. Fuels were chosen as representative of the main natural (e.g. dead leaves and litter duff) and modified (e.g. pine plantations, residuals of fuel treatments) ecosystems of each country. As the main factor controlling ignition, fuel moisture content (FMC) was controlled experimentally along a wide range (generally 5 to more than 50%). The main findings are: (i) the importance of the combination of the source of ignition, the wind speed and the fuel type to assess the ignition. It has been proved that ignition can vary strongly according to this ‘triangle’, with some sources of ignition being especially efficient for some fuel types, and the complex influence of wind that may increase or decrease the ignition success; (ii) the establishment of community- or species-specific logistic models of ignition versus FMC (see Figure below); (iii) the subsequent determination of fuel moisture of extinction for most fuels studied.
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Title: D3.3-1 Review of data structures for fuel database and protocols for fuel description /
Language: English
Description: Our overall goal in this work package can be defined as follows: “the systematic collection, storage and processing of knowledge on fuels for different users, with different needs, at different scales in order to assess the fuel complex and its fire potential from combustion to the landscape level”. We intend to: (1) collect, store and process existing knowledge on: (i) fuel acquisition protocols / fuel sampling methods; (ii) resulting fuel data categories & fuel models; (iii) allocation of fuel data categories & models to different fire behaviour & fire models at different scales. (2) generate, collect, store and process new knowledge on: (i) which fuel data protocol /fuel sampling method for which purpose at which scale? (ii) user needs: which user needs what at which scale, why & when/how often? This can be achieved by developing a knowledge platform with a single, on-line point of access. This will allow fire ecologists, modellers and managers (and eventually the general public) to access information on definitions, techniques for monitoring fuels, key fuel descriptors with regards to fire behaviour and impact and existing fuel models (Table 1). The system will help to harmonize fire control planning and experimental fire procedures across Europe, where many different approaches are in use (see EUFIRELAB report: UNIT2: D-01-02-01/06 http://www.eufirelab.org/). The system should provide a ‘Clearing House’ for data and information relating to fuel. This may be partly through the collection and storage of data in a single integrated system, and partly through the collection of metadata about information that will be stored elsewhere. We also propose to develop a wiki or bliki to which the fire community can contribute.
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Title: D5.3-1 Report on the effects of broad scale and long-term application of prescribed burning on fire risk components /
Language: English
Description: Effect of prescribed burning on the mitigation of fire risk was discussed in fire prone ecosystems of three European countries (Greece, France and Portugal). Two study cases were presented using two different fire modelling approaches, the spatial fire growth model FARSITE and FIRETEC a physically based fire propagation model. This study showed that fuel management with prescribed burning had a significant effect on fire propagation hazard. It needs to be completed with further studies on prescribed burning effects on the other fire risk components such as ignition likelihood or vulnerability (fire effects on trees). First results also showed the need of optimizing the spatial pattern of fire application both when applied extensively on the landscape, and when located on a fuel break network. The first study case concerned a conifer forest located in Kassandra peninsula in northern Greece, which has been affected by a 7120 ha wildfire in August 2006. Prescribed burning effectiveness was assessed by using the FARSITE simulator for comparing fire spread over the landscape before and after prescribed burning application on a network of stripe-shaped fuel-breaks. Analysis showed a significant reduction of fire potential (fireline intensity, flame length and total burned area) as a result of fuel treatments. The second study case concerned a shrubland and woodland mosaic in limestone Provence, France, where prescribed burning has been used as a fuel reduction tool for more than 15 years The effectiveness of prescribed burning was assessed by comparing fire potential (rate of spread, fireline intensity) before and in the years following prescribed burning treatments. Analysis carried out at the stand scale gave valuable information on the immediate potential fire hazard reduction after prescribed burning. In order to estimate the appropriate prescribed burning return interval, two management scenarios were used (i) a fire intensity threshold compatible with efficient and safe fire fighting or (ii) a shrub encroachment threshold easy to assess by forest managers. In both cases, the prescribed burning return interval varied from 2 to 3 years, depending on fuel types. When applying prescribed burning on a 15 years period, fire risk mapping on the whole State forest showed a higher fire risk reduction when using the fire intensity threshold than a fuel encroachment threshold. A third study case in the Portuguese mainland tested an important assumption of the fire paradox: does fuel age have an influence on burn probability and wildfire size? Fire frequency analysis of mapped fire perimeters ≥10 ha (1998-2008) indicated that fire occurrence was weakly to moderately dependent of fuel age. However, contrarily to the usual expectation, age-dependency did not decrease for larger fire size classes (i.e with increasingly extreme fire weather). Finally, we explored the variation in fire size statistics with fuel age. Older fuels (roughly >8 years after burning) were associated to more variable fire sizes, allowing much larger wildfires. From the results we infer that landscapes submitted to a mean prescribed fire return interval of 4 years will not support wildfires larger than 500 ha. However, adequate spatial planning of the treatments is expected to reduce the annual treatment rate. This deliverable contributes to solving the Fire Paradox because it clearly shows how fuel modification can decrease wildfire hazard and severity which is the first specific objective to be addressed in Integrated Wildland Fire Management. The state of the art chapter has shown that several fuel modification techniques, such as mechanical treatments, are available and used in Europe, but it has also demonstrated that prescribed burning although being increasingly used in some countries, still has to be strongly supported with the objective of the wisest complementarities between fuel treatments. Also, prescribed burning is the approach based on the paradox of fire, reducing fuels strategically before they can be used by wildfires, thus decreasing wildfire risk and severity.
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Title: Fire Paradox Fuel Manager /
Language: English
Description: The Fire Paradox Fuel Manager is a computer software integrated in the data processing chain between the European data and knowledge base on fuels (Fire Paradox Fuel Database) and the 3D physical-based fire propagation models. From a fire manager's point of view, vegetation is not only a conglomerate of plants, but it is also combustible organic material that holds a potential fire risk. It is therefore of great interest to assess the effects of silvicultural measures and fuel treatments to appraise their efficiency on fire hazard reduction. Within the Fire Paradox project such a fuel and fire effects assessment system has been developed. The Fire Paradox Fuel Manager enables users to analyse the relationships between vegetation characteristics, fire behaviour and post-fire impact on vegetation. The Fire Paradox Fuel Manager is a key application in the fire modelling process with the following major objectives: (1) to generate vegetation scenes in 3D to be used as input data for fire behaviour modelling; (2) to visualize fire effects on shrubs and trees; (3) to simulate post fire vegetation succession coupled with a plant growth model. The software has been developed on the Capsis (Computer-aided projection of strategies in silviculture) platform for modelling forest dynamics and stand growth. Capsis is a tool for forestry researchers, forest managers and educators.
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Title: D3.1-8 Dead fuel moisture modelling and validation /
Language: English
Description: This report presents the final results of researches developed about dead fuel moisture prediction, where empirical dead moisture content models fitted from atmospheric variables were analysed for: Pinus halepensis in Greece, Pinus sylvestris in Poland, and Pinus pinea, P. pinaster and P. radiata in Spain. Several types of fuels were considered: litter, duff and suspended needles. Moreover, an evaluation of the capability of different existing models to predict dead fuel moisture content in the above pine species and Eucalyptus globulus in Spain, and Nothofagus antarctica and Astrocedrus chilensis in Argentina was carried out. In general terms, FWI codes and the Sneeuwjagt and Peet values, adequately reflected the pattern of variation of fuel moisture of litter and duff. Still, the estimates of these models did not show sufficient accuracy to be used directly as predictors of the dead fuel moisture content. In periods not affected by precipitation, simpler vapour exchange models appeared to be suitable for dead fuel moisture content predictions.
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