The angiogenic growth of cities

Area of Science:

• Urban dynamics and city science
• Transport geography
• Mathematical modeling of urban systems

Background:

• Understanding urban population evolution is crucial for city science.
• Existing models lack a complete theoretical framework for space-time urban dynamics.
• Urban growth patterns are influenced by infrastructure development and economic factors.

Purpose of the Study:

• To reconstruct and model the space-time evolution of urban populations.
• To investigate the interplay between urban growth, transport networks, and economic constraints.
• To test the generalizability of a proposed model using London and Sydney case studies.

Main Methods:

• Reconstruction of urban evolution over 180 years for London.
• Development of a minimalist reaction-diffusion model coupled with economic constraints and adaptive transport networks.
• Application and validation of the model to Sydney's urban development from 1851 to 2011.

Main Results:

• Urban growth exhibits phases of diffusion-limited expansion and railway-driven suburbanization.
• The urban rail system coevolves with population, showing stable hierarchical characteristics.
• Transport schemes are identified as primary drivers of long-term urbanization patterns.

Conclusions:

• A reaction-diffusion model coupled with economic and transport factors can explain urban evolution.
• Sustainable city development requires understanding population-transport feedbacks.
• Large-scale interventions are needed to alter established transport-driven urbanization patterns.