Abstract:
Under global climate change, the combined effects of sea-level rise (SLR), typhoons, and storm surges have significantly exacerbated coastal flood risks in China, threatening socioeconomic sustainability. Severe seawater intrusion events—triggered by high SLR, astronomical tides, and storm surges along China’s coast—have revealed critical gaps in existing coastal defense systems. This study systematically reviews the recent evolution of SLR, typhoons, storm surges, and compound flood disaster risks in China’s coastal areas and proposes corresponding adaptation strategies. Key findings reveal that over the past few decades, climate warming has accelerated the global and regional SLR rates, intensified typhoon, and caused a poleward shift in storm tracks. The frequency of storm surges exceeding 2 m along China’s coast has doubled since the 1980s, particularly in Bohai Bay, the Zhejiang–Fujian coasts, and the Pearl River Delta. Compound floods exhibit three-dimensional interactions among the atmosphere, ocean, and land systems, with nonlinear amplification effects observed when SLR coincides with storm surges and pluvial flooding. By the end of this century, events currently classified as 100-year floods in the late 20th century may recur every few years or even more frequently. Northern coastal regions, such as Bohai Bay, are expected to face greater flood risks than before. The proposed response strategies are as follows. (1) Deepen mechanistic studies on multihazard coupling to enhance disaster prediction and early warning capabilities; (2) Develop a high-resolution dynamic risk assessment system and establish region-specific prevention and control plans; (3) Build a comprehensive flood defense system integrating ecological embankments, sponge cities, and intelligent drainage networks. The analysis also highlights the significant cost-effectiveness of implementing early warning systems and upgrading flood defenses. It is recommended to integrate dynamic risk assessment into the urban spatial planning framework of coastal cities while strengthening the protection and restoration of ecological barriers like coastal wetlands (e.g., mangroves and salt marshes). This study systematically examines the development patterns of coastal disasters under climate change and the associated response framework, providing a scientific basis for disaster risk management in China’s coastal regions.