Introduction

Megacities in India are urbanising at an unprecedented and irreversible rate, as the global proportion of urban population has increased from 28.3% in 1950 to 50% in 2010 (World Bank, 2011). Urbanization is one of the demographic issues in the 21st century in India (Ramachandra et al., 2012a,b). Understanding the process of urbanisation would help the city planners to understand and plan and eradicate the problems associated with increased urban area and population, and ultimately build a sustainable city. Urbanisation is one of the few major topics that has been studied focussing on socio-economic, and environmental perspectives in urban areas (Cohen, 2006), to economic perspectives in perieurban areas (Ravallion et al., 2007), to the loss of vegetation (Ramachandra et al., 2012a,b) and with respect to urban emissions (Banerjee and Srivastava, 2011; Ramachandra and Shwetmala, 2009; Fung et al., 2005). Qualitative attempts have also been made to summarize the development of urbanization studies (Morse, 1965). The urban process refers to the conversion of the rural and natural forms into urban areas due to population immigration into existing urban area. Ruraleurban migration is one of the major events that usually accompany economic expansion and hence leads to major agglomerations. Increased density of population has direct impact on the social and economic condition of the cities (Knox, 2009). This phenomenon is particularly significant in developing countries, where the ruraleurban areas become one of the very important places of urban growth. These peri-urban areas where the urban sprawl occurs are devoid of basic amenities and are normally left out on most of the civic governing body facilities (Ramachandra et al., 2012b). Urban sprawl considered to be one of the major reasons for rural push and spreading of city towards outskirts. The sprawl takes place at the urban fringes resulted in radial development of the urban areas or development along the highways results in the elongated development of urban forms (Sudhira et al., 2003). The urban sprawl quantifies the urban process and urban pattern. Urban Sprawl further affects the urban core areas by phenomena such as massive congestion, insufficient public transportation and infrastructure, lack of proper sanitation and many other basic amenities. With it come extreme socioeconomic disparities, vulnerability to natural and manmade risks (Fuchs et al., 1994; Mitchell, 1999; Kraas, 2007; Kraas and Nitschke, 2008; Ramachandra et al., 2012a). This necessitates the study of spatial urban growth patterns. Urban pattern refers to the spatial properties and configuration of the area at a particular time (Galster et al., 2001). Urban patterns also deals with physical structure and the spatial characteristics of the urban processes that vary over time (Aguilera et al., 2011). Urbanization process in Delhi has the major impact on the India’s urban development. The rapid increase of urbanization resulted in the increased population density. Geoinformatics such as Geographic Information systems (GIS) with the temporal remote sensing data help to quantify changes in landscape structure that result from various disturbances (Turner and Carpenter, 1998). Many landscape-level metrics have been developed to examine and provide meaningful ways of measuring landscape characteristics (e.g., O’Neill et al., 1988; McGarigal and Marks, 1995; Gustafson, 1998; Hargis et al., 1998; Jaeger, 2000; Ramachandra et al., 2012a,b). 

Spatial metrics measure the units derived from the spatial data that aid in quantifying the landscape features (Herold et al., 2002; Ramachandra et al., 2012a). The matric based spatial analyses provide quantitative characterizations of the spatial and time composition of landscapes, which would be useful to analyse and understand the changes in landscape structure and patterns (Henebry and Goodin, 2002). The combination of remote sensing and spatial metrics helps to derive spatial information about urban growth, its structure and dynamics that helps in understanding of urban growth processes (Deng et al., 2009; Ramachandra et al., 2012b). In this backdrop, the objectives of this communication i) understanding the urban dynamics through land cover and land use analysis, ii) understand the local level changes that takes place in the region using directional density gradients, iii) understand and quantify the growth and patterns through spatial metrics. This communication is divided into 4 parts. Part 1 gives details of the study area with its associated attributes. Part 2 discusses the methods adopted in the current research, third part deals with the results and discussion of the results. Final part draws the conclusion based on the analysis of the study area.