Urban transformation in the National Capital Territory of Delhi, India: The emergence and growth of slums?

• The study captures spatial urban transformation in the context to emergence and growth of slums.
• The study investigates the impact of municipal boundaries on the inclusion and exclusion of slums.
• Mapping built-up areas with census data and municipal boundaries help understand slum dynamics.
• Using scarce data and simple analytical techniques the study captures spatial slum dynamics.

In the 20th and 21st centuries, the world has experienced rapid urbanization and slum proliferation. Slum residents form a significant portion of urban populations and contribute to the development of cities. However, due to their highly concentrated consumption and waste production patterns, slums endure and exacerbate, among other things, environmental degradation. To date, our understanding of slums in Indian cities has been primarily based on census data and evidence from remote sensing images. These data do not yet provide spatial slum dynamics over time and are limited to static and statistical representation. In addition to the obsolescence of spatial data, the non-availability of consistent socio-economic data leads to data integration problems. Therefore, new approaches that consider the scarcity of data and the choice of analytical techniques are needed; planners without advanced technical training should also be able to easily apply these approaches. This study provides a comprehensive approach to examine the urban transformation of the National Capital Territory of Delhi (NCT-Delhi), India, from 1971 to 2011. Combining data from multi-temporal remote sensing images, census population statistics, slum enumeration and the provision of essential services, these investigations reveal a previously undocumented rapid increase in built-up areas outside municipal boundaries. The findings confirm the spatial shift of slums from the city center towards the periphery. The analysis provides a revealing insight: the emergence and growth of slums are outcomes of the prevailing urban planning environment, the limited success of adopted policies and the government's inability to foster growth.