Land Subsidence Measurement in Reclaimed Coastal Land: Noksan Using C-Band Sentinel-1 Radar Interferometry

Nur, A.-S.; Achmad, A.-R., and Lee, C.-W., 2020. Land subsidence measurement in reclaimed coastal land: Noksan using C-Band Sentinel-1 radar interferometry. In: Jung, H.-S.; Lee, S.; Ryu, J.-H., and Cui, T. (eds.), Advances in Geospatial Research of Coastal Environments. Journal of Coastal Research, Special Issue No. 102, pp. 218-223. Coconut Creek (Florida), ISSN 0749-0208.It has been 27 years since the beginning of the Noksan national industrial complex construction at downstream of the Nakdong River in Busan. The complex was built by landfilling a coastal area over one of Korea's deepest soft ground areas. Land subsidence occurred since the start of construction due to primary consolidation and secondary consolidation after the creation finished. Since secondary consolidation directly affects the structure over Noksan, it is crucial to monitor the subsidence rate. This study found that land subsidence happened in four areas of Noksan National Industrial Complex from 2017 to 2020 by applying Stamford Methods for Persistent Scatterer (StaMPS) time-series method using C-band Sentinel-1 SAR datasets from descending and ascending track. The results show land subsidence with a maximum velocity of 20.98 mm/year from descending track datasets and 20.92 mm/year from ascending track datasets. The highest rate area of land subsidence occurred in the south part of Noksan. Mean vertical deformation maps between descending and ascending track have been compared and show a good relationship with 0.93 of coefficient correlation. These approach methods in this study that using StaMPS could be used to monitor slow rate of land subsidence in reclaimed coastal land.