Impact of Urban Policies and City Development on the Increase of Land Subsidence in DKI Jakarta

Land subsidence is a widespread phenomenon, particularly in large cities situated near coastlines or alluvial plains, such as DKI Jakarta. This study aims to assess the rate and spatial distribution of land subsidence in DKI Jakarta over multiple time periods and predict land subsidence in the region by the year 2030.The Differential Interferometry Synthetic Aperture RADAR (DInSAR) method was employed in this research to acquire paired Synthetic Aperture RADAR (SAR) images with either identical spatial positions (differential SAR) or slightly different positions (terrain height InSAR) within the same area. The utilized SAR image data was from Sentinel-1 SLC covering the temporal range from 2018 to 2023. The analysis revealed that in 2018, 2019, 2020, 2021, and 2022, the respective rates of land subsidence were 0.08 m/year, 0.048 m/year, 0.1 m/year, 0.04 m/year, and 0.06 m/year. The most severe land subsidence occurred in North Jakarta, particularly in Marunda, Pantai Indah Kapuk, Muara Angke, and Muara Baru. In West Jakarta, significant land subsidence was observed in Kembangan and Cengkareng. The prediction indicates that the average land subsidence in DKI Jakarta in 2030 will be approximately 0.65 m or 65 cm, with a subsidence rate of about 0.0648 m/year or 6.48 cm/year. The impacts of land subsidence in DKI Jakarta include ROB (tidal flood) and land subsidence in residential areas and buildings, as well as a rise in sea levels exceeding the land elevation. The Jakarta Provincial Government has implemented measures by enacting policies regarding groundwater tax and establishing groundwater-free zones in the region.