Burned area determination using Sentinel-2 satellite images and the impact of fire on the availability of soil nutrients in Syria

Abstract

The objective of this research is the identification of burned forest areas that occurred in Syria from September 2nd to October 15th, 2020. Forest fire risk classes were determined using Sentinel-2 images. Normalized Burn Ratio (NBR), Differenced Normalized Burn Ratio (dNBR), and Burned Area Index for Sentinel-2 (BAIS2), and Normalized Difference Vegetation Index (NDVI) were used for the identification how much the forests have been destroyed and to establish fire risk classes. According to the study results, the size of the vegetation area that was destroyed due to fire was determined, and the probability of the forest fire exposure of these areas was established. The fires also altered some chemical properties in the soil during the combustion process. Thus, this study was focused on the impact of fire on the availability of soil nutrients. Soil samples were collected from three depths (0–10 cm, 10–20 cm and 20–30 cm) under the forest land a month after the fire in three locations: Al-Fazeen, Sawda and Gard Al-rihan. Pine (Pinus brutia) trees cover these areas. The results of this study indicated that the fire increased pH, EC and sand, the fire also led to an increase in the solubility of the available major soil elements N, P and K. There was an increase in the solubility of the soil microelements Zn, Cu, Mn and Fe while the content of organic material and silt and clay ratio decreased at the three sites in comparison with unburned soil.