Fire frequency analysis in Portugal (1975–2005), using Landsat-based burnt area maps
Sofia L. J. Oliveira A C , José M. C. Pereira A and João M. B. Carreiras B
+ Author Affiliations
- Author Affiliations
A Forest Research Centre, School of Agriculture, Technical University of Lisbon, Tapada da Ajuda, 1349-017 Lisbon, Portugal.
B Geoinformation for Development Centre, Department of Natural Sciences, Tropical Research Institute, R. Joao de Barros 27, 1300-319 Lisbon, Portugal.
C Corresponding author. Email address: sloliveira@isa.utl.pt
International Journal of Wildland Fire 21(1) 48-60 https://doi.org/10.1071/WF10131
Submitted: 23 October 2010 Accepted: 24 April 2011 Published: 24 October 2011
Abstract
Fire frequency in 21 forest planning regions of Portugal during the period 1975–2005 was estimated from historical burnt area maps generated with semi-automatic classification of Landsat Thematic Mapper (TM) satellite imagery. Fire return interval distributions were modelled with the Weibull function and the estimated parameters were used to calculate regional mean, median and modal fire return intervals, as well as regional hazard functions. Arrangement of the available data into three different time series allowed for assessment of the effects of minimum mapping unit, time series length and use of censored data on the Weibull function parameter estimates. Varying the minimum mapping unit between 5 and 35 ha had a negligible effect on parameter estimates, whereas changing the time series length from 22 to 31 years substantially affected the estimates. However, the strongest effect was caused by censored data. Its exclusion led to substantial overestimation of fire frequency and of burning probability dependence on fuel age. We estimated a country-wide mean fire interval of 36 years and an annual burnt area of 1.2%. Regional variations in fire frequency descriptors were interpreted in terms of land cover and land use practices that affect the contemporary fire regime in Portugal.
Additional keywords: censored data, Weibull model.
References
Abaimov SG, Turcotte DL, Shcherbakov R, Rundle JB (2007) Recurrence and interoccurrence behaviour of self organised complex phenomena. Nonlinear Processes in Geophysics 14, 455–464.| Recurrence and interoccurrence behaviour of self organised complex phenomena.Crossref | GoogleScholarGoogle Scholar |
AFN (2010) ‘National forest inventory of mainland Portugal (2005–2006).’ (Autoridade Florestal Nacional: Lisbon, Portugal) [in Portuguese]
Agee JK (1993) ‘Fire ecology of Pacific Northwest forests.’ (Island Press: Washington, DC)
Caetano M, Nunes V, Nunes A (2009) CORINE land cover 2006 for continental Portugal. Relatório Técnico, Instituto Geográfico Português. (Lisbon, Portugal)
Chandler C, Cheney P, Thomas P, Trabaut L, Williams D (1983) ‘Fire in forestry. Vol 1. Forest behaviour and effects.’ (Wiley: New York)
Díaz-Delgado R, Lloret F, Pons X (2004) Statistical analysis of fire frequency models for Catalonia (NE Spain, 1975–1998) based on fire scar maps from Landsat MSS data. International Journal of Wildland Fire 13, 89–99.
| Statistical analysis of fire frequency models for Catalonia (NE Spain, 1975–1998) based on fire scar maps from Landsat MSS data.Crossref | GoogleScholarGoogle Scholar |
Dodson B (2006) ‘The Weibull analysis handbook.’ 2nd edn. (ASQ Quality Press: Milwaukee, WI)
European Commission (2006) Forest fires in Europe 2005. European Commission, Directorate-General Joint Research Centre, Report 6. (Luxembourg) Available at www.pedz.uni-mannheim.de/daten/edz-bn/gdu/06/EUR_22312_EN.pdf [Verified 11 October 2011]
Fisher JL, Loneragan WA, Dixon K, Delaney J, Veneklaas EJ (2009) Altered vegetation structure and composition linked to fire frequency and plant invasion in a biodiverse woodland. Biological Conservation 142, 2270–2281.
| Altered vegetation structure and composition linked to fire frequency and plant invasion in a biodiverse woodland.Crossref | GoogleScholarGoogle Scholar |
Grissino-Mayer HD (1999) Modelling fire interval data from the American southwest with the Weibull distribution. International Journal of Wildland Fire 9, 37–50.
| Modelling fire interval data from the American southwest with the Weibull distribution.Crossref | GoogleScholarGoogle Scholar |
Heinselman ML (1973) Fire in the virgin forests of the Boundary Waters Canoe area, Minnesota. Quaternary Research 3, 329–382.
| Fire in the virgin forests of the Boundary Waters Canoe area, Minnesota.Crossref | GoogleScholarGoogle Scholar |
Heyerdahl EK, Agee JK (1996) Historical fire regimes of four sites in the Blue Mountains, Oregon and Washington. (University of Washington: Seattle, WA)
Johnson EA (1992) ‘Fire and vegetation dynamics: studies from the North American boreal forest.’ (Cambridge University Press: New York)
Johnson EA, Gutsell SL (1994) Fire frequency models. Methods and interpretations. Advances in Ecological Research 25, 239–287.
| Fire frequency models. Methods and interpretations.Crossref | GoogleScholarGoogle Scholar |
Kraaij T (2010) Changing the fire management regime in the renosterveld and lowland fynbos of the Bontebok National Park. South African Journal of Botany 76, 550–557.
| Changing the fire management regime in the renosterveld and lowland fynbos of the Bontebok National Park.Crossref | GoogleScholarGoogle Scholar |
Lepart J, Debussche M (1992) Human impact on landscape patterning: Mediterranean examples. In ‘Landscape boundaries: consequences for biotic diversity and ecological flows’. (Eds AJ Hansen, F di Castri). (Springer-Verlag: New York)
Lloret F, Marí G (2001) A comparison of the medieval and the current fire regimes in managed pine forests of Catalonia (NE Spain). Forest Ecology and Management 141, 155–163.
| A comparison of the medieval and the current fire regimes in managed pine forests of Catalonia (NE Spain).Crossref | GoogleScholarGoogle Scholar |
Mather AS, Pereira JMC (2006) Transição Florestal e Fogo em Portugal. In ‘Incêndios Florestais em Portugal’. (Eds JS Pereira, JMC Pereira, FC Rego, JMN Silva, TP Silva) pp. 257–286. (ISA Press: Lisbon, Portugal)
McCarthy MA, Gill AM, Bradstock RA (2001) Theoretical fire-interval distributions. International Journal of Wildland Fire 10, 73–77.
| Theoretical fire-interval distributions.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38zosVCksQ%3D%3D&md5=d365417fb7bb70c3f6c0ec71d00097a8CAS |
Miranda P, Coelho FES, Tomé AR, Valente MA, Carvalho A, Pires C, Pires HO, Pires VC, Ramalho C (2006) 20th Century Portuguese climate and climate scenarios. In ‘Alterações Climáticas em Portugal. Cenários, Impactos e Medidas de Adaptação – Projecto SIAM II’. (Eds FD Santos, P Miranda) pp. 23–84. (Gradiva: Lisbon, Portugal)
Moreno JM (1999) Forest fires: trends and implications in desertification-prone areas of Southern Europe. In ‘Mediterranean Desertification: Research Results and Policy Implications: Proceedings of the International Conference, Vol. 1’ 29 October–1 November, Crete, Greece. (Eds P Balabanis, D Peter, A Ghazi, M Tsogas) European Commission, Directorate-General Research, EUR 19303, pp. 115–150. (Luxembourg)
Moreno JM, Vázquez A, Vélez R (1998) Recent history of forest fires in Spain. In ‘Large forest fires’. (Ed. JM Moreno) pp. 133–158 (Backhuys: Leiden, the Netherlands)
Moritz MA (2003) Spatiotemporal analysis of controls on shrubland fire regimes: age dependency and fire hazard. Ecology 84, 351–361.
| Spatiotemporal analysis of controls on shrubland fire regimes: age dependency and fire hazard.Crossref | GoogleScholarGoogle Scholar |
Moritz MA, Keeley JE, Johnson EA, Shaffner AA (2004) Testing a basic assumption of shrubland fire management: how important is fuel age? Frontiers in Ecology and the Environment 2, 67–72.
| Testing a basic assumption of shrubland fire management: how important is fuel age?Crossref | GoogleScholarGoogle Scholar |
Moritz MA, Moody TJ, Miles LJ, Smith MM, de Valpine P (2009) The fire frequency analysis branch of the pyrostatistics tree: sampling decisions and censoring in fire interval data. Environmental and Ecological Statistics 16, 271–289.
| The fire frequency analysis branch of the pyrostatistics tree: sampling decisions and censoring in fire interval data.Crossref | GoogleScholarGoogle Scholar |
Nunes MCS, Vasconcelos MJP, Pereira JMC, Dasgupta N, Alldredge RJ, Rego FC (2005) Land cover type and fire in Portugal: do fires burn land cover selectively? Landscape Ecology 20, 661–673.
| Land cover type and fire in Portugal: do fires burn land cover selectively?Crossref | GoogleScholarGoogle Scholar |
O’Donnell AJ, Boer MM, McCaw WL, Grierson PF (2010) Vegetation and landscape connectivity control wildfire intervals in unmanaged semi-arid shrublands and woodlands in Australia. Journal of Biogeography 28, 37–48.
Oliveira SLJ (2008) Análise da frequência do fogo em Portugal Continental (1975–2005) com a distribuição de Weibull. MSc thesis, ISA, UTL, Lisbon, Portugal.
Pausas JG, Vallejo R (1999) The role of fire in European mediterranean ecosystems. In ‘Remote sensing of large wildfires in the European Mediterranean basin’. (Ed. E Chuvieco) pp. 3–16. (Springer: Berlin)
Pereira JMC, Santos MTN (2003) ‘Fire risk and burned area mapping in Portugal.’ (Direcção-Geral das Florestas: Lisbon, Portugal)
Pereira JS, Correia AV, Correia AP, Branco M, Bugalho M, Caldeira MC, Cruz CS, Freitas H, Oliveira AC, Pereira JMC, Reis RM, Vasconcelos MJ (2002) Forests and biodiversity. In ‘Climate change in Portugal. Scenarios, impacts and adaptation measures. SIAM Project’. (Eds FD Santos, K Forbes, R Moita) pp. 363–414. (Gradiva: Lisbon, Portugal)
Pereira MG, Trigo RM, DaCamara CC, Pereira JMC, Leite SM (2005) Synoptic patterns associated with large summer forest fires in Portugal. Agricultural and Forest Meteorology 129, 11–25.
| Synoptic patterns associated with large summer forest fires in Portugal.Crossref | GoogleScholarGoogle Scholar |
Pereira JMC, Carreiras JMB, Silva JMN, Vasconcelos MJ (2006) Alguns conceitos básicos sobre os fogos rurais em Portugal. In ‘Incêndios Florestais em Portugal’. (Eds JS Pereira, JMC Pereira, FC Rego, JMN Silva, TP Silva) pp. 133–161. (ISA Press: Lisbon, Portugal)
Polakow DA, Dunne TT (1999) Modelling fire-return interval T: stochasticity and censoring in the two-parameter Weibull model. Ecological Modelling 121, 79–102.
| Modelling fire-return interval T: stochasticity and censoring in the two-parameter Weibull model.Crossref | GoogleScholarGoogle Scholar |
Santos C, Leite A, Santos E, Pinho J (2005) A estratégia sectorial florestal num sistema de planeamento regional 5.º Congresso Florestal Nacional, Viseu, Portugal.
Schultz J (2005) ‘The ecoregions of the world – the ecological divisions of the geosphere.’ (Springer: Berlin)
Trigo RM, Pereira JMC, Pereira MG, Mota B, Calado TJ, DaCamara CC, Santo FE (2006) Atmosfheric conditions associated with the exceptional fire season of 2003 in Portugal. International Journal of Climatology 26, 1741–1757.
| Atmosfheric conditions associated with the exceptional fire season of 2003 in Portugal.Crossref | GoogleScholarGoogle Scholar |
Turcotte DL, Abaimov SG, Shcherbakov R, Rundle JB (2007) Nonlinear dynamics of natural hazards. In ‘Nonlinear dynamics in geosciences’. (Eds A Tsonis, J Elsner) pp. 557–580. (Springer: New York)
Vázquez A, Moreno JM (2001) Spatial distribution of forest fires in Sierra de Gredos (Central Spain). Forest Ecology and Management 147, 55–65.
| Spatial distribution of forest fires in Sierra de Gredos (Central Spain).Crossref | GoogleScholarGoogle Scholar |
