Assessing Typhoon Soulik-induced morphodynamics over the Mokpo coastal region in South Korea based on a geospatial approach

Abstract. The inner shelf and coastal region of the Yellow Sea along the Korean Peninsula are frequently impacted by typhoons. The Mokpo coastal region in South Korea was significantly affected by Typhoon Soulik in 2018, the deadliest typhoon strike to the southwestern coast since Typhoon Maemi in 2003. Typhoon Soulik overran the region, causing extensive damage to the coast, shoreline, vegetation, and coastal geomorphology. Therefore, it is important to investigate its impact on the coastal ecology, landform, erosion/accretion, suspended-sediment concentration (SSC), and associated coastal changes along the Mokpo region. In this study, the net shoreline movement (NSM), normalized difference vegetation index (NDVI), fractional vegetation coverage (FVC), coastal-landform change model, normalized difference suspended-sediment index (NDSSI), and SSC–reflectance relation have been used to analyze the coastal morphodynamics over the typhoon periods. We used pre- and post-typhoon Sentinel-2 MultiSpectral Instrument (MSI) images for mapping and monitoring the typhoon effect and recovery status of the Mokpo coast through short- and medium-term coastal-change analysis. The findings highlighted the significant impacts of typhoons on coastal dynamics, wetland vegetation, and sediment resuspension along the Mokpo coast. It has been observed that typhoon-induced SSC influences shoreline and coastal morphology. The outcome of this research may provide databases to manage coastal environments and a long-term plan to restore valuable coastal habitats. In addition, the findings may be useful for post-typhoon emergency response, coastal planners, and administrators involved in the long-term development of human life.