A spatiotemporal analysis of compound typhoon storm surge disasters in China

Abstract The compound typhoon storm surge disaster (CTSSD) is a major Marine disaster in China. Understanding its spatiotemporal characteristics is of great significance for its prevention and mitigation. Characterized by a large spatial scale (China) and a long time series (1989-2020), this paper proposes a framework to investigate the probability and intensity under different compound scenarios. The framework contains two dimensions, time and space, and methods such as the Mann-Kendall test, the Standard Deviation Ellipse model, and the Spatial clustering analysis are adopted. Subsequently, the links between observed characteristics with policy, adaptation, and geography are explored, and suitable risk governance recommendations for Chinese CTSSD are proposed. The results show that the probability characteristics of different compound scenarios are different. This is closely related to the uneven spatiotemporal distribution of precipitation, typhoon landings, and the tide range of astronomical tide, and thus a pattern of "wind and precipitation prevention in South China, and astronomical tide prevention in North China" is proposed. The probability shows an increasing trend but the intensity shows a downward trend, suggesting that policies taken by China (such as building high-standard seawalls, developing technology, and institutional construction) reduce the damage of CTSSD effectively. By understanding the global excellent cases, a suggestion of "use both 'soft' measures and 'hard' measures, develop community-based CTSSD management" is put forward, which is hoped to provide new ideas for the prevention and management of CTSSD in China.