Research on subsidence monitoring based on high resolution SAR data: A case study of Jakarta

Subsidence is a serious environmental geological problem in China and even in the whole world. Synthetic Aperture Radar Interferometry (InSAR) is being developed as a main method for subsidence monitoring. Many geo-environmental conditions of Jakarta are similar to those in Chinese coastal cities such as Shanghai and Guangzhou. As Jakarta is an important city on the 21st-Century Maritime Silk Road, the research on subsidence monitoring methods in Jakarta can produce experience for the same work in Chinese coastal cities and can also provide valuable information for the ‘One Belt, One Road’ Initiative. Based on 12 scenes of 3m-resolution TerraSAR-X images acquired between June 2010 and March 2011, the authors studied and applied Small BAseline Subsets (SBAS) and 2-pass differential InSAR (DInSAR) methods. On the average subsidence velocity map produced by SBAS, 5 subsidence cones, which are located in west, north and east Jakarta and the northern part of Bekasi City, can be identified, with the maximum velocity up to 9 cm/a. After analyzing the time series 2-pass DInSAR interferograms, it was found that the cone in the northern part of Bekasi City had remarkable non-linear character because its subsidence value could reach 6cm in 44 days between December 2010 and January 2011. It can be concluded that high resolution TerraSAR-X data and proper DInSAR methods can support the work of subsidence mitigation in Jakarta and the similar cities.