Coastal areas around the world are urbanizing rapidly, despite the threat of sea level rise and intensifying floods. Such development places an increasing number of people and capital at risk, which calls for public flood management as well as household level adaptation measures that reduce social vulnerability to flooding and climate change. This study explores several private adaptation responses to flood risk, that are driven by various behavioral triggers. We conduct a survey among households in hazard-prone areas in eight coastal states in the USA, of which, some have recently experienced major flooding. While numerous empirical studies have investigated household-level flood damage mitigation, little attention has been given to examining the decision to retreat from flood zones. We examine what behavioral motives drive the choices for flood damage mitigation and relocation separately among property buyers and sellers. Hence, we focus on the drivers that shape demand for future development in flood-prone cities. We find that households’ choices to retreat from or to avoid flood zones (1) are highly sensitive to information that provokes people's feelings of fear, and (2) rely on hazardous events to trigger a protective action, which ideally would take place well before these events occur. We highlight that major flooding may cause a potential risk of large-scale outmigration and demographic changes in flood-prone areas, putting more low-income households at risk. Therefore, coordinated policies that integrate bottom-up drivers of individual climate adaptation are needed to increase urban resilience to floods.

尽管海平面上升和洪水加剧的威胁，世界各地的沿海地区仍在迅速地实现城市化。这种发展使越来越多的人和资本处于危险之中，这就要求进行公共洪水管理以及采取家庭级适应措施，以减少社会对洪水和气候变化的脆弱性。这项研究探讨了由各种行为触发因素驱动的针对洪水风险的几种私人适应措施。我们对美国八个沿海州多灾多发地区的家庭进行了一项调查，其中一些家庭最近遭受了严重洪灾。尽管许多实证研究已经研究了减轻家庭洪水危害的方法，但很少有人关注检查从洪水区撤退的决定。我们研究了哪些行为动机分别在房地产买卖双方之间推动了减轻洪灾损失和搬迁的选择。因此，我们将重点放在影响易发洪水城市未来发展需求的驱动因素上。我们发现，家庭退避或避开洪灾区的选择（1）对引起人们恐惧感的信息高度敏感，并且（2）依靠危险事件来触发保护性行动，理想情况下应该早于这些事件发生。我们着重指出，大水灾可能会在容易发生洪灾的地区造成大规模移民和人口变化的潜在风险，使更多的低收入家庭面临风险。因此，需要采取协调一致的政策来整合自下而上的个人气候适应驱动力，以增强城市的抗洪能力。