LAND SUBSIDENCE ANALYSIS IN PALEMBANG CITY USING DIFFERENTIAL INTERFEROMETRIC SAR

Abstract

Palembang is a city that has expanded from the banks of the Musi River to the surrounding plains, including river deltas and reclaimed swampy regions, increasing the risk of land subsidence, particularly in low-lying areas. Continuous changes in subsurface conditions have led to excessive land deformation, posing risks to buildings, underground infrastructure, and overall human safety. Recently, land subsidence in Palembang has become a growing concern due to its impact on infrastructure development and worsening waterlogging caused by rising sea levels encroaching on the mainland. This study employs Synthetic Aperture Radar (SAR) imagery and the Differential Interferometric SAR (D-InSAR) method to map areas of subsidence and uplift in Palembang. As of August 2024, subsidence values in the city range from -14 cm to -51.4 cm, with the Swamp Deposit (Qs) area being the most affected. Geological analysis indicates that subsidence is influenced by population growth, urban infrastructure expansion, increasing building floor area, and the presence of the reservoir-bearing Airbenakat Formation. The most significant subsidence occurred in relatively young Quaternary deposits, likely due to compaction-induced settling. Compared to other Indonesian cities—Jakarta (-3 to -10 cm/year), Semarang (-6 to -8 cm/year), Surabaya (-6 to -10 cm/year), and Bandung (-7.6 to -23 cm/year)—Palembang exhibits a substantial rate of land subsidence. To mitigate this issue, a more adaptive spatial development strategy should be prioritized to reduce subsidence and ensure sustainable urban growth.