[U-03] Remote Sensing Role in Sustainable Development

[U03-P07] Monitoring Land Subsidence in Makassar Using Differential Interferometric SAR (DInSAR)

*Aswar Syafnur¹, Samsu Arif¹, Elzaskiah Drajat², Mirnayani Mirnayani³ (1.Geoinformatics Laboratory, Department of Geophysics, Hasanuddin University, 2.Program Study of Geophysics, Department of Geophysics, Hasanuddin University, 3.Program Study of Geomatics Engineering, Departement of Geodesy, Gadjah Mada University)

Keywords:DInSAR, Land subsidence, Makassar City, Radar Interferometry

Makassar City poses a serious threat of land subsidence driven by geological conditions, infrastructure loading, and excessive groundwater extraction. Geologically, the area consists of alternating volcanic rocks and compact marine sediments, but it is overlaid by younger, softer deposits such as sand, swamp sediments, and delta deposits. This study aims to evaluate the land subsidence rate using the Differential Interferometry Synthetic Aperture Radar (DInSAR) method. DInSAR enables the analysis of topographic changes by comparing the phase differences of radar waves from Sentinel-1 Single Look Complex (SLC) images acquired during the 2022–2023 period. The results indicate that the land subsidence rate in Makassar City ranges from 4 to 19.4 cm/year, showing a significant increase compared to previous studies from 2007–2011, which reported subsidence rates between 0.09 and 5.8 cm/year. These findings confirm that rapid urbanization contributes to the acceleration of land subsidence, highlighting the need for mitigation efforts and more sustainable groundwater resource management strategies.