Estimating urban growth in peri-urban areas and its interrelationships with built-up density using earth observation datasets

Understanding the complex nature of urban dynamics, especially in the fast-growing cities of developing countries, has become crucial to the urban planners and researchers. It is also relevant from the viewpoint of smart city projects as the foundation of successful smart city lies in proper planning and urban growth analysis. In this context, the present study attempts to assess the urban expansion and land-change dynamics in and around Delhi. Multi-temporal Landsat data of 1977, 2003 and 2014 were used for analyzing the spatio-temporal pattern of built-up density, urban expansion, spatial change and their interrelationships. The annual urban expansion index of the study area reveals that it was comparatively high in Delhi National Capital Territory (NCT) during 1977-2003, but the expansion was much higher in peri-urban centers in the later period. However, the growth was not happened homogeneously across the peri-urban zones; instead, it occurred around few urban centers of peri-urban area. The annual urban expansion of Delhi NCT (2.52) was significantly less than peri-urban centers like Gurgaon (6.19) in the period, 2003-2014. Since the areas with high built-up density have little or no space for new settlement, the expansion of built-up area took place in the less dense areas. The correlation between urban expansion index and annual rate of change in built-up area shows that there is a good agreement and significant positive relationship (r >= 0.62) present between them. A negative correlation (r >= 0.92) between built-up density and urban expansion index indicates that areas with high built-up density have less potentiality to expand and vice versa.