Monitoramento dos focos de calor e do risco de incêndios florestais no município de Ituiutaba-MG

Abstract

The monitoring of heat foci and the risks of forest fires are very important for the identification of the periods, the weather conditions and areas most susceptible to the occurrence of forest fires, which cause environmental damage, Social and economic. In This sense, the objective of this work was to monitor the heat foci and the risk of forest fires in the municipality of Ituiutaba-MG. To achieve the proposed objective, the following steps were performed: 1-Quantification of heat foci between the years 2008 to 2017, which were obtained through the National Institute of Spatial Research (INPE); 2-Correlation of heat foci with weather conditions (Temperature °c, Precipitation (mm), Relative Humidity (%) and Wind Velocity (m/s) and with the Forest Fire Hazard Indexes (Angstron Index, Nesterov, Telicyn, Monte Alegre Formula and Modified Monte Alegre Formula) between May and October 2017. These data were obtained through the Automatic Meteorological Station of Ituiutaba-MG; 3-Obtaining The Normalized Difference Vegetation Index, using bands 4 and 8 of the Sentinel-2 satellite between May and October 2017; 4-Calculation of the structural risk that corresponds to factors that do not vary over time. The following factors Were considered:d istance of roads and urban area, land use and vegetation cover, hipsometria, slope and orientation of the slopes; 5-Calculation of the dynamic risk that is related to the ignition potential of the combustible material, consisting of three factors: Precipitation, water Deficit and NDVI in the period from May to October of 2017; 6-Calculation of the integrated risk that associates the structural and dynamic risk. It was Found that the months of July, August and September showed the highest amounts of accumulated heat foci, 320, 406 and 563, respectively. The meteorological conditions that had the highest significant correlations with the heat foci were the relative humidity of the air and the wind velocity. However, there was no significant correlation with the forest fire hazard indexes. Regarding NDVI, the months of August (0.25) and October (0.24) presented the lowest values. Finally, in the analysis of the integrated risk it was verified that the greatest risks of occurrence of forest fires were presented in the months of May, August, September and October.