A Revised Historical Fire Regime Analysis in Tunisia (1985–2010) from a Critical Analysis of the National Fire Database and Remote Sensing

• Main Authors: Chiraz Belhadj-Khedher, Nikos Koutsias, Anastasia Karamitsou, Taoufik EI-Melki, Bahri Ouelhazi, Abdelazziz Hamdi, Habiba Nouri, Florent Mouillot
• Format: Article
• Language: English
• Published: MDPI AG 2018-01-01
• Series: Forests
• Subjects: forest fire; remote sensing; fire regime; data quality assessment; Mediterranean ecosystems
• Online Access: http://www.mdpi.com/1999-4907/9/2/59

Long-term fire history reconstructions provide fruitful information in the context of global change. Global remotely-sensed burned areas offer a uniform estimate of fire regimes worldwide, but hardly capture small fire events and cover only the last 20 years. Burned areas from national statistics often lack credibility due to discrepancies in fire report protocols between countries, partial data records and uncertain burned area estimates from field observations. However, they constitute a unique and valuable alternative long-term key source of information. We provide here a detailed critical analysis of the fire database in Tunisia, on the southern boundary of the Mediterranean basin and with a contrasted socio-economic environment compared to the more studied European side. We analyzed the fire record database with a quality checking protocol, combined with remote sensing burned area characterization from Landsat images. The high uncertainties in fire numbers could not lead to any conclusion for an accurate trend estimate. The corrected burned area lead to an average yearly burned area of 1799 ha year−1 compared to previous estimates of 1017 ha year−1, leading to a fraction of burnable land affected by fires of 0.19%, on the lowest range of observations in the Mediterranean basin. From this corrected database, we revised the usually assumed burned area decrease in this region, with no significant trend detected over the 1985–2010 period. We conclude on the need for thorough assessment of data quality in fire history reconstruction from national statistics to prevent misleading conclusions, and for an increased credibility, in order to be further used in fire models benchmarking or fire weather analysis. Our results can contribute to the under-represented fire regime analysis on the southern boundary of the Mediterranean basin.