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There are urgent calls for new approaches to map the global urban conditions of complexity, diffuseness, diversity, and connectivity. However, existing methods mostly focus on mapping urbanized areas as bio physical entities. Here, based on the continuum of urbanity framework, we developed an approach for cross-scale urbanity mapping from town to city and urban megaregion with different spatial resolutions using the Google Earth Engine. This approach was developed based on multi-source remote sensing data, Points of Interest – Open Street Map (POIs-OSM) big data, and the random forest regression model. This approach is scale-independent and revealed significant spatial variations in urbanity, underscoring differences in urbanization patterns across megaregions and between urban and rural areas. Urbanity was observed transcending traditional urban boundaries, diffusing into rural settlements within non-urban locales. The finding of urbanity in rural communities far from urban areas challenges the gradient theory of urban-rural development and distribution. By mapping livelihoods, lifestyles, and connectivity simultaneously, urbanity maps present a more comprehensive characterization of the complexity, diffuseness, diversity, and connectivity of urbanized areas than that by land cover or population density alone. It helps enhance the understanding of urbanization beyond biophysical form. This approach can provide a multifaceted understanding of urbanization, and thereby insights on urban and regional sustainability.

Segregation by racialized categories is common to cities across the world and its social effects are well studied. However, the environmental effects—the ecology of segregation—have received less attention. Racialized segregation persists through time and is associated with environmental hazards or lack of amenities. The environmental burdens of racial segregation are increasingly documented and this paper synthesizes the dynamics of segregation and the dynamics of ecological conditions associated with it. The ‘adaptive cycle of resilience,’ an important social–ecological theory, is applied and used to facilitate synthesis. The well-documented history of racial segregation in the US city of Baltimore, Maryland, is used to illustrate the systemic mechanisms that adapt segregation to changing social conditions, and hence maintain its ecological impacts. The adaptive cycle serves as a useful tool in evaluating and addressing the ecology of segregation and can thus advance urban ecology on a new horizon. Practice relevance The adaptive cycle of resilience demonstrates that persistent racial segregation in cities results from an intentional but flexible system that includes many seemingly banal practices. These include planning, zoning, patterns of investment, influence of the real estate industry, distribution of amenities and disamenities, and access to civic power and influence. The adaptive cycle shows that the persistence of segregation is not ‘natural’ or inevitable. Rather, segregation persists as a result of racialized policies and practices that exclude certain groups from civic goods and processes. Acknowledging that cycles of segregation have been, and are being, institutionally maintained identifies a system that may be disrupted by community action, policy adjustment, and planning practice.