Application of PS-InSAR Technique for Measuring the Coastal Subsidence in the East Coast of South Korea

Abstract

Subsidence is a widespread phenomenon caused by both natural and anthropogenic activities, particularly in the coastal areas. Eventually, the impact of coastal subsidence can affect the monitoring of sea level rise by in-situ tidal gauge stations. The Korean peninsula is one of such areas that reported considerably rapid sea level rise than the global average in the recent years. Therefore, there is a need for assessing the land subsidence component of relative sea level rise for better future prediction models. Space borne interferometric SAR technique provides millimeter level of accuracy in displacement measurements. The objective of this study is to estimate the earth's surface movements along the coastal areas of Pohang, South Korea. To achieve that, we acquired C-band Sentinel-1 data during 2016 2017. Time-series Stanford Method of Persistent Scatter (StaMPS) InSAR analysis proved technique to measure displacements at high resolution with reduced decorrelation noise from interferograms. The results showed about 1.83 cm/year subsidence in the Pohang coastal area, whereas significant sea level rise is observed in this region. The results will provide further insight into the localized subsidence rates in the study sites and its impact on the sea level monitoring.