Determination of changes in topography by unmanned aerial vehicle

In this study, the landslide area located in Harmandalı Neighborhood, Çiğli District, Izmir Province, was selected as the application site. In this region, where small local landslides occur, the Mw:6.9 earthquake that occurred on October 30, 2020, on the Island of Samos and affected Izmir, caused significant ground movements in large masses and inflicted considerable damage to the surrounding structures. Within the scope of the study, landslide activity was monitored using photogrammetric methods and GNSS measurement techniques. Due to the large impact area, an unmanned aerial vehicle was used, and photogrammetric flights were conducted at specific intervals. The data obtained from the flights were processed to produce a digital elevation model and an orthophoto map of the region. Deformation and seasonal change maps were generated based on the height differences between the surface models produced at different periods. GNSS measurements were conducted at points established in the region within the same periods, and GNSS deformation differences were obtained using a similar strategy. By evaluating the deformation and seasonal change maps, vertical deformations in the landslide area were identified, and horizontal deformations in the region were detected when examining the GNSS measurement points.