The inequality of economic development increases the direct economic loss of storm surge disaster in China

The coastal zone is the most intensive area of global economic activity and has been threatened by marine hazards. As climate change increases the vulnerability of coastal communities worldwide, coastal hazard management has become one of the most urgent tasks for ocean governance. While economic development may enhance social resilience, economic inequality, a side effect of economic growth, can play a significant role in social vulnerability to natural hazards. Coastal managers and policymakers urgently need relevant analyses to understand the relationship between economic inequality and marine hazards. Here, we analyzed the links between economic inequality and direct economic losses from storm surge disasters in 11 coastal regions of China between 2000 and 2020. Our results show that provincial income inequality significantly increases direct economic losses from storm surge disasters. For every 1% increase in the provincial disposable income Gini index, annual losses increase by 4.8%–7.8%. Moreover, with a 1% increase in the provincial income gap, relative annual losses (compared with provincial GDP) increase by 0.051%–0.056%. Heterogeneity analysis reveals that losses in northern and eastern marine economic circles are most affected by income inequality. We also find that with increasing economic development level, the aggravating effect of income inequality on losses becomes more significant. Our work indicated that achieving income equity may be a crucial factor for coastal hazard mitigation, which provides new insights into global coastal hazard management.