Future urban development exacerbates coastal exposure in the Mediterranean

Area of Science:

• Environmental science
• Urban planning
• Climate change adaptation

Background:

• Coastal flood risk is increasingly influenced by urban development patterns.
• Existing urban extent projections lack the spatial resolution and temporal scope for broad coastal flood assessments.
• The Mediterranean region faces significant coastal flood exposure due to its urbanized coastlines.

Purpose of the Study:

• To develop spatially explicit urban extent projections for ten Mediterranean countries under the Shared Socioeconomic Pathways (SSPs).
• To assess the impact of different urban development scenarios on future coastal flood exposure.
• To inform long-term coastal adaptation and land-use planning strategies.

Main Methods:

• An Urban Change Model was developed using an artificial neural network.
• Input variables included elevation, population density, and road networks.
• Projections were generated for five SSPs across ten Mediterranean countries.

Main Results:

• Future urban development projections show significant variations in coastal urban exposure based on chosen scenarios.
• Coastal urban exposure in the Extended Low Elevation Coastal Zone (E-LECZ) could increase by up to 104% by 2100.
• The spatial patterns of urban development critically influence coastal flood risk assessments.

Conclusions:

• Spatially explicit urban development projections are essential for accurate coastal flood risk assessment.
• Land-use planning, informed by these projections, can be an effective strategy for mitigating future coastal flood risk.
• Considering diverse urban development scenarios is vital for robust adaptation planning in coastal regions.