Exploring Urban Sprawl and Sustainability in the National Capital Territory of Delhi: Patterns, Challenges, and Projections

Urbanization and its diverse forms and patterns have become central to global research as the world shifts its focus toward building sustainable, resilient, and livable cities. As urban areas grow in size and population, unplanned development frequently leads to inefficient land use, unsustainable spatial transformations, environmental degradation, and inadequate urban services. Addressing these challenges is critical to global sustainability, particularly when viewed through the lens of the urban critical zone—a dynamic space where human activities and natural systems interact, influencing resource flows and urban resilience.

Delhi, the National Capital Territory of India, exemplifies these challenges and opportunities, making it an ideal case study for urbanization. As one of the world's fastest-growing metropolitan regions, it has undergone rapid demographic and spatial transformations, characterized by unique patterns of urban sprawl and rural-urban transitions. Understanding Delhi’s urban growth trajectory provides valuable insights into managing similar dynamics in other rapidly urbanizing regions.

This study examines the urban growth patterns of Delhi over the period 1990 to 2024 using satellite imagery and GIS to analyze spatial and temporal dynamics. The study adopts a multi-method approach to capture the complexities of urban growth. The three-growth mode hypothesis (infill, edge-expansion, and leapfrogging) is applied to identify and quantify distinct spatial dynamics of urbanization. Urban Field Intensity (UFI) analysis highlights areas experiencing maximum growth, while the Normalized Difference Expansion Index (NDEI) is used to assess sprawling or shrinking tendencies of the city over time. Future urban growth for the years 2030 and 2050 is projected using spatial simulation techniques, integrating historical growth trends, population dynamics, and land-use data to predict potential urban transformations. Additionally, field visits to critical zones—including rapidly transforming rural areas, infill-dominated regions, and outlying development zones—were conducted to validate spatial analyses and explore human-environment interactions. These combined approaches provide a comprehensive framework to evaluate urban growth and its implications for sustainability.

The results reveal that Delhi's urban growth is predominantly characterized by edge-expansion, with intermittent infill and leapfrogging patterns. Declining NDEI values across the study period indicate increased sprawl, posing sustainability challenges. UFI analysis highlights significant land transformation in rural areas, with specific zones experiencing up to a 60% increase in urban activity. The adjacent counter-magnet cities of Ghaziabad, Noida, Faridabad, and Gurugram significantly influence the region's urban dynamics. Field observations corroborate these findings, revealing acute infrastructure deficits in transition zones, particularly in water supply, transportation networks, and waste management. These insights underscore the urgency of targeted interventions to address sustainability challenges in Delhi’s sprawling urban regions.

This study underscores the need for region-specific strategies that harness sprawling tendencies to achieve sustainable urban growth. By advocating for the "make room" paradigm, it emphasizes urban planning approaches that integrate the interactions between human activities and critical biophysical processes to enhance resilience in rapidly growing urban areas.

Keywords: Urbanization, Urban sprawl, Sustainability, Urban critical zone, Spatial analysis