Spatiotemporal trajectories of built-environment using centroid shift model: a directional understanding of urban evolution
摘要
For centuries, the evolution of the built environment has presented complex interactions between different urban features that demand continued research. This study addresses a gap in systematic directional approaches for geospatial urban planning by investigating the complex spatiotemporal evolution of the Mumbai Metropolitan Region (MMR) built environment from 1975 to 2019. To statistically validate this relationship beyond intuitive observations, our research sought to quantify the built environment’s distribution, growth intensity, and orientation. The methodology employed here is the spatial-geometric Centroid Shift Model, computing area-weighted centroids from multi-source satellite data across five distinct periods (1975, 1990, 1999, 2009, and 2019) for the cities within MMR. It quantifies the direction and magnitude of urban growth through shift vectors across cities and computes a net growth direction using vector summation. The study classifies cities into uni, bi, and multi-directional growth patterns based on variation in shift angle and distance, as well as their behaviour. These classifications and spatial metrics inform evidence-based planning strategies for corridor development, densification, or zoning interventions. To further evaluate whether urbanization follows planned infrastructure, cosine similarity is applied between centroid shift angles and transport azimuths. This research provides a robust and foundational framework for a directional understanding of urban growth patterns, filling a critical gap in urban planning methodology. Additionally, the study demonstrates a scalable, data-efficient method that relies on minimal inputs, making it adaptable for other rapidly urbanizing or resource-constrained regions. This novel approach can also optimize assumptions in future growth prediction models.