Author(s): Zhi-Yong Long; Huan-Feng Duan

Linked Author(s): HF Duan

Keywords: Coastal flooding; Climate change; Rainfall; Storm Surge; Sea Level Rise

Abstract: This paper presents a study on the coastal urban flooding risk assessment through numerical modelling and analysis. The urban area of Kowloon in Hong Kong is taken for case study, with aim to examine the influences of different factors including rainfall, storm surge, and sea level rise under extreme weather conditions. To this end, a coupled model framework of one-dimensional (1D) drainage networks and two-dimensional (2D) overland flows is developed based on the open-source codes, which is then validated and applied for the investigation. For analysis, different scenarios of rainfalls and storm surges with 50-year, 100-year, and 200-year return periods respectively, coupled with SLR scenarios of 0.5 meter and 1 meter, are examined for the consequences of coastal urban flooding including flooding area and depth. The findings highlight the significant differences in the induced flood risk distribution and intensity across different scenarios. Based on the various numerical cases and results, the dynamic evolution of flooding risks in this studied area is also inspected in both temporal and spatial domains. These models, results and findings are not only pivotal for enhancing flood risk management in Hong Kong but also valuable for other coastal urban areas with similar challenges under climate change.

DOI: https://doi.org/10.3850/iahr-hic2483430201-83

Year: 2024