Detection of rapid land subsidence of civil constructions with TerraSAR-X interferometry

The TerraSAR-X SAR system provides high spatial resolution and geometric accuracy imagery which supports well the mapping of the 3-D structure of large-scale civil infrastructure and its motions (4-D). In this work, we investigated the potential of TerraSAR-X observations for monitoring rapid land subsidence induced by reclamation activities. A case study was conducted in Hong Kong Disneyland Theme Park (DTP) at the Penny´s Bay, one of the largest land reclamation projects worldwide. A total of 16 TerraSAR-X scenes were used in a small-baseline PSI method for retrieving residual reclamation settlement in the study area. The preliminary results indicate that a remarkably high density of high coherent point targets (>2,500 PS point/km²) was identified in the reclamation area and a large land subsidence rate on the order of 35 cm/yr could be detected in the center of reclaimed land. The high detail level of deformation filed as well as the high sensitivity regarding rapid residual settlement makes TerraSAR-X interferometry a remarkable potential Earth Observation technique to enable the detection of ground deformation related to the large-scale infrastructure development in reclaimed land.