514 / 2024-06-24 09:29:07

The Elementary Study of Storm Surge in Typical Estuaries of South China

storm surge;,typhoon;,tide-surge interaction,wave-induced current

Subtheme 1: Water-related Hazard and Risk Reduction > Topic 2: Simulation and Forecast of Water Hazard

The river tributaries and forks in southern China are numerous, and rainfall is concentrated during the rainy season. During the typhoon season, the coastal areas of river estuaries are easily affected by the combined impact of summer floods, storm surges, typhoon waves, and astronomical high tides, which can inundate large areas of farmland and residential areas, causing significant losses to people's lives and property. Establishing mathematical models, analyzing the temporal and spatial patterns of storm surges, identifying the main factors affecting their changes, and developing forecasting models are the primary methods of current research on storm surge disasters. This paper takes the largest estuary in South China, the Pearl River Delta, as the study area, and establishes a storm surge model that considers the combined impact of floods, astronomical tides, and typhoon waves. Taking two super typhoons with similar paths as case studies, the temporal and spatial variation patterns of storm surges are analyzed through numerical simulations. The results show that typhoon waves and astronomical tides both have significant effects on the water level rise of storm surges. The change in radiation stress caused by wave breaking in coastal areas leads to a significant increase in water level rise of storm surges in offshore estuaries. Astronomical tides have a negative correlation effect on storm surge water level rise by influencing the variation of water depth. This rule is confirmed through experiments on the phase difference between storm surges and astronomical tides. In addition, we also analyze the impact of typhoon landing places on storm surges in the Lingdingyang Bay.