Publicação
Fire regime in the Iberian Peninsula : links with current and future climate
| Resumo: | Iberia has been affected by wildfires in the last decades, in association with fire weather extremes, as observed in recent years. The main objective of this thesis is to investigate the current and future fire regime in Iberia, with three research questions: (i) Were there recent changes in fire regime or in pyro-regions of Iberia?; (ii) What is the relationship between extreme fire weather and Burnt Area (BA) in Portugal?; and (iii) Will future climate modify the Iberian fire regime or pyro-regions? Several fire weather indices, containing the Daily Severity Rating (DSR), were computed using a reanalysis dataset. A cluster analysis was performed on Normalized Burnt Area (NBA), revealing four pyro-regions. The Number of Extreme Days (NED), defined using DSR and Drought Code above the 95th percentile, was computed and related with the NBA. ERA5-Land reanalysis data was used to compute DSR percentiles for an extended summer period and related with large wildfires in Portugal, to identify which percentile is associated to the majority of accumulated BA. A cluster analysis was performed using this relationship and related with land use data, to analyse the spatial variability of this threshold. The strong link between the NED and the NBA intra-annual patterns was used to project the future pyro-regions, using a climate ensemble for two future scenarios. Projected changes in NED suggested different future Iberian pyro-regions mapping. In conclusion, the three research questions were answered: (i) Recent changes in fire regimes were observed, influenced by fire weather alterations; a strong link between the NED and NBA was disclosed; (ii) Extreme DSR days were responsible for the majority of BA; forest or shrublands prevalence has influence in the spatial variability of this extreme threshold; (iii) Iberian pyro-regions may change profoundly in future climate conditions, with an increase of the NED and DSR. |
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| Autores principais: | Menezes, Tomás |
| Assunto: | Fogos rurais Alterações climáticas Risco meteorológico de incêndio Piroregiões Península Ibérica Wildfires climate change fire weather risk pyro-regions Iberia |
| Ano: | 2022 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Iberia has been affected by wildfires in the last decades, in association with fire weather extremes, as observed in recent years. The main objective of this thesis is to investigate the current and future fire regime in Iberia, with three research questions: (i) Were there recent changes in fire regime or in pyro-regions of Iberia?; (ii) What is the relationship between extreme fire weather and Burnt Area (BA) in Portugal?; and (iii) Will future climate modify the Iberian fire regime or pyro-regions? Several fire weather indices, containing the Daily Severity Rating (DSR), were computed using a reanalysis dataset. A cluster analysis was performed on Normalized Burnt Area (NBA), revealing four pyro-regions. The Number of Extreme Days (NED), defined using DSR and Drought Code above the 95th percentile, was computed and related with the NBA. ERA5-Land reanalysis data was used to compute DSR percentiles for an extended summer period and related with large wildfires in Portugal, to identify which percentile is associated to the majority of accumulated BA. A cluster analysis was performed using this relationship and related with land use data, to analyse the spatial variability of this threshold. The strong link between the NED and the NBA intra-annual patterns was used to project the future pyro-regions, using a climate ensemble for two future scenarios. Projected changes in NED suggested different future Iberian pyro-regions mapping. In conclusion, the three research questions were answered: (i) Recent changes in fire regimes were observed, influenced by fire weather alterations; a strong link between the NED and NBA was disclosed; (ii) Extreme DSR days were responsible for the majority of BA; forest or shrublands prevalence has influence in the spatial variability of this extreme threshold; (iii) Iberian pyro-regions may change profoundly in future climate conditions, with an increase of the NED and DSR. |
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