Impact of Wildfires on Land cover in African Mediterranean forest: A case study of the august 2021 fire in Tizi Ouzou region (Algeria), using LANDSAT (8) satellite images

Abstract

This study investigates the impact of the wildfire that swept through the Tizi Ouzou region in Algeria's eastern Tell Atlas on August 8, 2021. The fire ravaged approximately 506.3 km², prompting an analysis based on Landsat 8 satellite imagery using the Normalized Burn Ratio (NBR), Normalized Differenced Vegetation Index (NDVI), and Differenced Normalized Burn Ratio (dNBR). The research assessed the severity of fire damage across six predominant land cover types in the study area and tracked their recovery levels over a two-year span following the incident. Forty-two random sample points were selected from these land cover types, representing about 95% of the primary features within the affected areas. A strong positive correlation (R² = 0.918) was identified between dNBR and dNDVI, offering insight into burn severity trends categorized from high and moderate risk to low-risk zones. Data from NBR and NDVI indices revealed that fruit trees, particularly olive orchards, suffered the most significant post-fire loss, with reflectance values declining by -120.80% for NBR and -78.30% for NDVI. By contrast, two years after the fire, NDVI indices demonstrated gradual recovery across land cover types, marking an average restoration of 16.31% compared to the critical post-fire NDVI values of -75.92%.