DIGITALNA ARHIVA ŠUMARSKOG LISTA
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|ŠUMARSKI LIST 7-8/2023 str. 60 <-- 60 --> PDF|
The results refer to the visual and digital interpretation of the obtained classified rasters, the interpretation of statistically obtained accuracy indicators, and the final presentation of the difference between the classified rasters.
In the previous chapter were presented the statistically obtained accuracy indicators, indicating the fact that the classification, in relation to the test sample, meets the expected accuracy.
In the first part of the results analysis, a visual and computational overlapping of the rasters of the classified Sentinel-2 images from 2017 and 2022 was performed. The analysis was performed to show the changes occurring in limited areas in short intervals.
Figure 3 shows the difference between the two classified images from 2017 and 2022. The Sentinel-2 images for 2017 were taken in two-time intervals, August and November. Although the choice of recording time intervals is not ideal, it was not possible to choose other intervals due to bad weather conditions during the acquisition. Although there are certain errors in the classified image from 2017, it is possible to decipher certain changes that were visually confirmed based on Google Earth Pro, and presented in Figure 3.
The second part of the analysis compares Real Estate Cadastre Data for the cadastral municipality of Brezici, which was created based on a survey from 1976, to Sentinel-2 images from 2022. Due to the modern, urban life that has been in effect for the last 20 years, changes are happening at a very high rate, which is almost impossible to capture using traditional survey methods. Owing to the development of remote sensing, it is possible to see, with appropriate accuracy, the extent of the changes that have occurred and to propose adequate assessment methods as the next steps. The difference between cadastral data and data obtained from Sentinel-2 images is shown in Figure 4. Table 2 shows the confusion matrix out of which computational conclusions about the difference between these two rasters can be drawn.