InSAR Time-Series Analysis of Basin-Scale Deformation and Environmental Dynamics in the Golbasi Basin (Adiyaman, Türkiye)

Natural processes such as tectonic movements, subsidence, erosion, and hydrological variability continuously modify the coastline and basin morphology. Understanding these changes is essential for interpreting the dynamics of coastal and lacustrine systems and their responses to both gradual and sudden events. In this study, basin-scale deformation and environmental dynamics of Lake Golbasi (Adiyaman, Türkiye) were investigated within the East Anatolian Fault Zone (EAFZ), where one of the main fault branches passes directly through the Golbasi district. The Mw 7.8 Kahramanmaras earthquake that occurred on February 6, 2023, caused significant surface deformation, coastline reconfiguration, and localized subsidence, highlighting the strong coupling between tectonic activity and surface processes in the region. Time-dependent ground deformation was monitored using InSAR time-series analysis based on Sentinel-1 C-band SAR data acquired in both ascending and descending geometries and processed through the LiCSBAS framework and the ASF HyP3 cloud-based processing system, covering the period from 2021 to 2025. This temporal coverage allows the investigation of pre- and post-earthquake deformation and coastline changes, as well as their spatial and temporal relationship with the active fault system in the Golbasi Basin. The tectonic interpretation of the observed deformation features was further supported through an evaluation of the orientation and spatial position of the identified surface deformation patterns relative to mapped fault traces, post-earthquake surface ruptures, and the distribution of seismic activity. The Normalized Difference Water Index (NDWI) was applied to optical Sentinel-2 imagery to better characterize the basin’s dynamic environmental conditions and to support the interpretation of the observed deformation signals. Seasonal NDWI variations between dry and wet periods were examined to assess changes in water extent and shoreline position. This information was essential for distinguishing surface variability related to hydrological processes from deformation driven by tectonic activity. The integrated analysis reveals a complex interaction between tectonic deformation, seasonal water-level fluctuations, and basin-scale environmental dynamics. These findings improve our understanding of post-earthquake changes in the Golbasi Basin and offer explanations for how fault-controlled lakes and wetlands evolve and gradually stabilize following major seismic events.