| dc.description.abstract | The changes in land cover occur dynamically and unpredictably due to both human activities and natural processes. Particularly during emergencies such as natural
disasters and war events, there is a need for a change detection (CD) workflow to obtain information on land cover changes. With the advancement of remote sensing technology, improved hardware, and easy accessibility to high-resolution imagery, remote sensing has become a valuable tool for detecting land cover changes. However, existing object-based CD methods face challenges in practical applications, it is
necessary to spend time adjusting the parameters of the segmentation method and visually analyzing the accuracy of the segmentation layer. This process requires more time to achieve in practical application scenarios. For those algorithms utilizing tools such as artificial intelligence (AI) lack transparency, making it difficult to assess the
importance of change features.
Therefore, this study aims to develop a semi-automatic change detection method to address these limitations. This method utilizes object-based CD to generate land surface change maps. In the case of abrupt change areas in Chiayi, sudden change areas are identified using SPOT-7 imagery. In the case of the 918 earthquake event in Hualien, Pléiades imagery is used to detect damaged bridges and seasonal land surface cover changes. In both cases, an accuracy assessment is conducted for CD with relative radiometric calibration (RRC) and feature screening (FS), CD without relative radiometric calibration and feature screening, and CD without relative radiometric calibration but with feature screening.
The detection results in the Chiayi case reveal not only changes in agricultural land cover but also attempts to identify non-seasonal change areas, with a maximum overall
accuracy of 86%. In the Hualien case, the overall accuracy reaches up to 84%, and the change map includes both seasonal variations and the collapsed Gao-Liao Bridge caused by the earthquake. Among the three tests of our results, it is noteworthy that the CD accuracy after atmospheric correction is less effective compared to CD without relative radiometric calibration, which is associated with the method of atmospheric correction. | en_US |