ICFBR 2011International Conference on Fire Behaviour and RiskAlghero, Italy - October 4-6, 2011sia sui dati annuali sia su quelli stagionali. I <strong>di</strong>versi modelli si sono caratterizzati da scarsa precisione della stima <strong>di</strong> FD, mentrei migliori risultati sono stati ottenuti per LFD. La temperatura e l‘umi<strong>di</strong>tà relativa sono risultate le variabili meteorologichemaggiormente correlate con la probabilità <strong>di</strong> incen<strong>di</strong>. In generale, si è ottenuta una maggiore accuratezza laddove sono statiutilizzati i valori me<strong>di</strong> della temperatura minima e massima <strong>di</strong> 3 e 7 giorni anziché i valori me<strong>di</strong> giornalieri <strong>di</strong> tali variabilimeteorologiche.Dans cette étude, nous analysons le régime des incen<strong>di</strong>es, la tendance climatique et les relations entre les incen<strong>di</strong>es et le climatdans le bassin de Asağı Köprüçay (Antalya, Turquie), une zone d‘environ 205,000 ha. La zone d‘étude est très concernée parles incen<strong>di</strong>es de forêt. Puisque les données historiques sur les incen<strong>di</strong>es sont devenues consistantes après 1979, nous avonsanalysé la période historique 1979-2009. En ce qui concerne l‘analyse du climat, les données de quatre stationsmétéorologiques représentant les <strong>di</strong>fférentes con<strong>di</strong>tions climatiques de la zone étu<strong>di</strong>ée ont été prises en considération. Lesenregistrements quoti<strong>di</strong>ens des valeurs maximum, moyennes et minimum des températures, des précipitations, de la vitesse et<strong>di</strong>rection du vent, de l‘humi<strong>di</strong>té relative ont été utilisés pour l‘analyse. Au cours de la période étu<strong>di</strong>ée, les températuresmoyennes et minimum ont montré une tendance statistique à la croissance dans le temps. Les tendances du nombred‘incen<strong>di</strong>es, zones brûlées et données météorologiques ont été analysées en utilisant les techniques de corrélation et derégression linéaire. En ce qui concerne les tendances historiques du nombre d‘incen<strong>di</strong>es, aucune tendance statistiqueimportante n‘a été observée du fait de la haute variabilité annuelle des données. Les zones brûlées ont montré une tendancegénérale à la hausse qui n‘est pas statistiquement importante. Aucune corrélation statistique importante entre le nombred‘incen<strong>di</strong>es et la zone brûlée n‘a été observée. La relation entre les paramètres climatiques et les principaux in<strong>di</strong>cateurs del‘activité d‘incen<strong>di</strong>e: les jours d‘incen<strong>di</strong>e (FD, au moins un incen<strong>di</strong>e par jour), les jours de grands incen<strong>di</strong>es (LFD, au moins 20hectares par jour), jours d‘incen<strong>di</strong>es multiples (MFD, plus d‘un incen<strong>di</strong>e par jour), ont été examinés en leur appliquant larégression logistique. La relation historique entre les variables climatiques et les principaux in<strong>di</strong>cateurs de l‘activité d‘incen<strong>di</strong>e(FD, LFD, MFD) a été analysée à l‘aide d‘un ensemble de modèles de régression logistique. En particulier, 4 modèles ontdonné la meilleure réponse combinée dans la prévision des <strong>di</strong>fférents in<strong>di</strong>ces d‘activité d‘incen<strong>di</strong>e pour les données annuelles etsaisonnières. Les <strong>di</strong>fférents modèles se sont caractérisés par une faible précision des estimations de FD, tan<strong>di</strong>s que LFD aenregistré les meilleurs résultats. La température et l‘humi<strong>di</strong>té relative ont montré que les variables climatiques ont pour laplupart une corrélation avec la probabilité d‘activité d‘incen<strong>di</strong>e. On a obtenu généralement une augmentation de la précision làoù des valeurs moyennes minimales et maximales des températures de 3 et 7 jours ont été exploitées au lieu des valeursmoyennes quoti<strong>di</strong>ennes des variables climatiques.94
ICFBR 2011International Conference on Fire Behaviour and RiskAlghero, Italy - October 4-6, 2011CF.16 - Trends in number of fires and burned area and their relationships with climatic variablesacross regions in Spain during 1974-2008Zavala G. 1 , Urbieta I.R. 1 , Rieiro I. 1 , Be<strong>di</strong>a J. 2 , Gutiérrez J.M. 2 , Moreno J.M. 11. Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Av. Carlos III s/n, 45071 Toledo, Spain;2. Santander Meteorology Group, Instituto de Física de Cantabria. CSIC-Universidad de Cantabria, Av. de los Castros 44,39005 Santander, Spaingonzalo.zavala@uclm.esUnderstan<strong>di</strong>ng past trends in fire occurrence and the relationship between fire and climatic variables is of utmostimportance in the Me<strong>di</strong>terranean countries. In this study we used the Cana<strong>di</strong>an Fire Weather Index (FWI) and itscomponents to determine what relationships exist between fire danger and monthly number of fires and burned areaacross Spain, and how these relationships have varied in the last 35 years. We analyzed fire statistics (number of firesand burned area, 1974-2008), and the ERA-40 reanalysis database (1974-2001) as input for constructing the FWI.We performed trend analysis and maximum likelihood fire-climate models for the various regions within peninsularSpain and the Balearic Islands. Despite the overall trend of increasing FWI in most of Spain during the last decades,our study shows that <strong>di</strong>fferent regions have been undergoing <strong>di</strong>fferent trends. While in some regions an increasingtrend in the number of fires was detected, in others the opposite trend was detected. Some regions <strong>di</strong>d not exhibitany pattern in burned area, but in some a decreasing trend was demonstrated. In ad<strong>di</strong>tion, we found significantrelationships between the number of fires and monthly burned area and fire danger in<strong>di</strong>ces considering just themeteorological variables. In general, as FWI increased more fires or more burned area occurred. In the mostNorthern regions, where milder climatic con<strong>di</strong>tions and lower fire danger in<strong>di</strong>ces are prevalent, fire activity washighest and so were the correlations between the number of fires and burned area. However, Central, Southern andEastern regions showed no fires below a threshold (FWI of 5 to 10), but then, fire activity increased up to values ofFWI of 40-50. It is remarkable that the relationships varied among regions, some having a saturating-type ofrelationship while others a more exponential one. The goodness of fit and the variance explained by the models wasremarkable for some regions. Most of the Me<strong>di</strong>terranean regions were the most poorly related to the FWI.Therefore, at least some of the regions with greatest fire activity were not pre<strong>di</strong>ctable. Overall, our study shows thatannual burned area is not increasing in Spain in most regions, and even decreasing in some, despite increased firedanger con<strong>di</strong>tions. Yet, the significant relationships between FWI and burned area in<strong>di</strong>cates that ignitions and firefighting capacity might be controlling the lack of, or negative, trend in burned area demonstrated for some regions.Keywords: burned area, climate, Fire Weather Index, fire risk, Me<strong>di</strong>terraneanComprendere le tendenze del passato nell‘incidenza <strong>degli</strong> incen<strong>di</strong> e il rapporto fra questi ultimi e le variabiliclimatiche è <strong>di</strong> massima importanza per i paesi del Me<strong>di</strong>terraneo. In questo stu<strong>di</strong>o abbiamo utilizzato l‘in<strong>di</strong>cecanadese Fire Weather Index (FWI) e le sue componenti per determinare quali relazioni esistevano fra il pericolod‘incen<strong>di</strong>o e il numero d‘incen<strong>di</strong> mensili con l'area incen<strong>di</strong>ata in tutta la Spagna, e come queste sono cambiate negliultimi 35 anni. Abbiamo esaminato le statistiche sugli incen<strong>di</strong> (numero d‘incen<strong>di</strong> e area colpita, 1974-2008) e ildatabase <strong>di</strong> ri-analisi ERA-40 (1974-2001) come elementi per realizzare l‘in<strong>di</strong>ce FWI. Abbiamo eseguito l‘analisidel trend e i modelli <strong>di</strong> massima probabilità <strong>di</strong> clima favorevole agli incen<strong>di</strong> per le varie regioni all‘interno dellaSpagna peninsulare e delle Isole Baleari. Nonostante il complessivo aumento dell'in<strong>di</strong>ce FWI, in gran parte dellaSpagna negli ultimi decenni, il nostro stu<strong>di</strong>o rivela che le varie regioni hanno avuto dei trend <strong>di</strong>fferenti. Mentre inalcune è stato in<strong>di</strong>viduato un trend in aumento del numero <strong>degli</strong> incen<strong>di</strong>, in altre regioni è stato in<strong>di</strong>viduato un trendopposto. Alcune regioni non hanno mostrato nessuno schema tipico nell‘area incen<strong>di</strong>ata, ma in alcune altre è statoevidenziato un trend in <strong>di</strong>minuzione. Inoltre, abbiamo riscontrato delle relazioni in<strong>di</strong>cative fra il numero d‘incen<strong>di</strong> el‘area incen<strong>di</strong>ata mensilmente e gli in<strong>di</strong>ci del pericolo d‘incen<strong>di</strong>o considerando solo le variabili meteorologiche. Ingenere, parallelamente all‘aumento dell‘in<strong>di</strong>ce FWI c‘è stata una maggior incidenza <strong>di</strong> incen<strong>di</strong> o <strong>di</strong> aree colpite. Nelleregioni più a nord, dove sussistono con<strong>di</strong>zioni climatiche più miti e in<strong>di</strong>ci più bassi <strong>di</strong> pericolo d‘incen<strong>di</strong>o, l‘attivitàincen<strong>di</strong>aria è stata maggiore così come la correlazione fra il numero <strong>di</strong> incen<strong>di</strong> e l‘area colpita. Tuttavia, le regioniCentrali, Meri<strong>di</strong>onali e Orientali non hanno rivelato presenza <strong>di</strong> incen<strong>di</strong> al <strong>di</strong> sotto della soglia (FWI da 5 a 10), mapoi, l‘attività incen<strong>di</strong>aria è aumentata fino a valori <strong>di</strong> FWI fra 40 e 50. C‘è da notare che le relazioni variavano fra leSESSION 3: Climate and Fires95