17 JAN 2023 (TUE) 15:35 - 16:05

Impacts of coastal urbanization on relative sea-level rise

Ms LIANG Xindan

Abstract:

Under the background of global climate change, the impact of global mean sea-level rise (GMSLR), resulting in flooding, and extreme sea level events on coastal ecosystems, environment, infrastructure, population migration, and other aspects have been studied extensively. However, as one of the major human activities, how coastal urbanization influences relative sea-level rise (RSLR) in coastal areas has not been well understood. Relative sea level is usually recorded by tide gauges which measure sea-level height relative to the land where it is attached. This research focuses on the direct and indirect impacts of urbanization on RSLR. The direct impact is mainly contributed by the land subsidence caused by human reconstruction of terrain and extraction of groundwater, oil, and gas resources in the process of urbanization. Land subsidence will accelerate RSLR in coastal areas. The indirect effect is through a large amount of greenhouse gas emissions caused by the urbanization process, which exacerbates climate change, and global warming, and thus contributes to RSLR. Based on the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China, this study aims 1) to explore the characteristics of RSLR based on the time-series tide gauge data and time-frequency analysis in GBA, 2) to extract the land subsidence and generate the long-term trend of RSL removing vertical land movement through interferometric synthetic aperture radar (InSAR) technologies, and 3) to investigate the direct and indirect impacts of urbanization on RSLR based on the structural equation model (SEM) and ground observations. The results of the study will provides a better understanding of the impacts of urbanization on RSLR and the interrelationship between human activities and sea-level rise for better coastal management and sustainable development.