Overestimating coastal urban resilience: The groundwater problem

Climate vulnerability assessments of coastal cities rarely include groundwater flooding induced by sea level rise. Unlike surface flooding from tides or storm surge, groundwater flooding is not prevented by seawalls. In cities where the underlying geology is relatively impermeable, groundwater can be drained and pumped over floodwalls as a defensive measure, as is done in the Netherlands. In areas where the underlying geology is highly permeable, managed retreat may be the only practical option. Considering the impacts of groundwater flooding is essential to improving urban vulnerability assessments and formulating realistic resilience strategies.

Automated summary

Coastal cities' vulnerability assessments often overlook groundwater flooding caused by sea level rise, which differs from surface flooding. Cities with impermeable geology can drain and pump groundwater as a defense, while managed retreat may be the only option in highly permeable areas. Considering groundwater flooding is crucial for enhancing urban vulnerability assessments and developing realistic resilience strategies.