Decoding peri-urban transformation through multi-scale mapping of bidirectional urbanisation.

Area of Science:

• Urban Geography
• Geospatial Analysis
• Sustainable Development

Background:

• Rapid urbanization in emerging economies challenges sustainable development principles.
• Urban expansion in India often exceeds administrative boundaries, particularly in non-metropolitan areas.
• Conventional analyses inadequately capture the bidirectional nature of urban sprawl.

Purpose of the Study:

• To develop a novel, data-driven geospatial framework for delineating dynamic urban expansion boundaries.
• To quantify bidirectional urban growth patterns.
• To provide actionable intelligence for sustainable urban management in transforming city-regions.

Main Methods:

• A three-tiered approach combining buffer analysis, centroid shift analysis, and landscape metrics.
• Buffer analysis to identify the spatial threshold of built-up expansion.
• Centroid shift and landscape metrics to track directional change and fragmentation/aggregation.

Main Results:

• Salem's built-up area increased by approximately 170% between 2001 and 2020.
• A compact urban core with a fragmented, expanding periphery was observed.
• Neighboring towns showed bidirectional expansion towards Salem, indicating interconnected regional growth corridors.

Conclusions:

• The developed framework redefines urban boundaries using quantitative spatial metrics.
• It enables early detection of emergent urban linkages and sprawl intensities.
• Findings support sustainable and equitable urban expansion management in rapidly developing regions.