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ŠUMARSKI LIST 7-8/2022 str. 64     <-- 64 -->        PDF

measurements and entered into the SPreAD-GIS. In order to determine the ambient noise level, noise measurement was made for five minutes when the chainsaw was not operated and no noise source was active in the field.
Developing noise propagation maps – Izrada karata širenja buke
In SPreAD-GIS environment, spatial propagation model of anthropogenic noise was developed by considering six noise propagation factors and three frequency bands (500, 1000, 2000 Hz). Maps showing the noise propagation at intervals of 5 dBA were produced in raster data format as model outputs. Noise propagation calculations in the SPreAD-GIS were conducted for a total of 40 combinations. In the final noise propagation maps, the combination that gives the highest pixel value among the combinations for each pixel was taken into account. By calculating the difference between the noise arising from the noise source and the natural noise levels in the working environment, the areas where the noise emitted from the source is likely to be heard and the areas where the bird species in the area may be affected were determined. The areas with noise levels of 45 dBA and above, which were determined to affect breeding, stress hormone levels and species richness in bird species, were identified for this purpose (Shannon et al., 2016). In addition, regions where the difference between the noise originating from the noise source and the natural noise difference in the area exceeds 20 dBA and above, which is critical for bird species, were determined (Proto et al. 2016).
Noise analysis results – Rezultati analize buke
Noise level measurements were performed during the tree cutting stage carried out in the alder stands located in the Section 52 in the study area. The results indicated that the average tree diameter was approximately 33 cm and the minimum, maximum and average noise values ​​were approximately 72 dBA, 109 dBA and 99 dBA, respectively. Accordingly, it was determined that the average noise level was more than the danger limit (90 dBA) that causes an increase in physiological reactions and headache. It has been determined that the maximum noise level was above 120 dBA, which can cause continuous damage and disturbance of balance in the inner ear. Within the scope of the study, the effect of tree diameters on the noise level caused by the chainsaw was investigated. Although the results of One-Way Analysis of Variance showed that there was no statistically significant relationship between diameter classes and noise level (p> 0.05), it was determined that the noise values ​​increased from the small diameter class to the medium and large diameter class (Table 2).
Model database results – Rezultati modela baze podataka
In order to produce the noise propagation map using SPreAD-GIS, firstly, the model database was developed. Noise measurements and climate data collection were performed in four periods for 40 combinations and there were 10 combinations in each period. According to the results, the average maximum noise value and average ambient noise for all noise combinations were found to be 109.3 dBA and 42 dBA, respectively (Table 3). On the other hand, average temperature, relative humidity, wind direction and wind speed were found to be 14 ° C, 66%, 75° and 5.8 km/h, respectively. Seasonal conditions were determined as “clear, calm summer day” for the first period and “clear, calm winter day” for other three periods.
Necessary digital data layers were produced in order to evaluate the effects of the noise locations, terrain structure, and land cover type on noise propagation in the SPreAD-GIS process. The center point of 120 grids generated in Section 52 was evaluated as the noise source in the SPreAD-GIS database. In order to reflect the impact of the terrain structure into the model, DEM was produced for the