INTRODUCTION

Rapid urbanisation is quite alarming, especially in developing countries like India. Nature and human systems are getting affected due to growing urbanisation at all geographic scales (Herold et al., 2005). This unprecedented urbanisation process has been fueled by rapid economic growth and even more rapid industrialisation. With most of the value added economic activities and populations located in urban areas, how well cities function as a system will determine the future of Indian cities. One of the factors which will determine the success of growing cities is inevitably the land use and management.

Urban sprawl has increasingly become a major issue facing many metropolitan areas (Ji, 2006). Bangalore is one among the fastest urbanising cities in Asia, undergoing redevelopment for economic purposes and is witnessing tremendous pressure on the infrastructure, civic amenities, public services, etc. A huge migrating population, increasing number of Information Technology and Bio-Technology firms, and large scale real estate developments are demanding more resources within the city, forcing it to expand both horizontally and vertically leading to serious problems like informal settlements, environmental pollutions, destruction of ecological structures, unemployment, etc. This unprecedented growth and urban sprawl are often unnoticed by the planners and policy makers as they are unable to visualise this type of growth patterns. Sprawl patterns are fundamental to many of the spatial-temporal relationships and it is important to understand the factors and trend that influence the growth of the urbanising landscape. Therefore, characterising and understanding the changing patterns of urban growth is critical, given that urbanisation continues to be one of the major global environmental changes in foreseeable future (Rashed, 2008).

The spatio temporal trends of urban sprawl and urbanisation can be characterised by temporal remotely sensed (RS) images acquired through space-borne satellites. Their large area coverage and repeat viewing provide information over a considerable range of spatial and temporal resolutions for mapping land cover (LC) resources (Mas, 2010). They provide additional levels of information about the links between land use and infrastructure change and a variety of social, economic and demographic process (Herold, et al., 2005). RS intertwined with time series modeling and geographical (spatial) metrics (urban indicators) are very effective to understand the growth of urban areas for administration and future planning of the landscape. A landscape is a mosaic of several patches, which is a discrete area of relatively homogeneous environmental conditions whose boundaries are distinguished by differences in environmental character from its surroundings. Spatial metrics are used to improve the understanding and representation of urban dynamics and urban patches and helps to develop alternative conceptions of urban spatial structure and change. In general, a large number of urban patches would suggest a landscape having urban sprawl where it is difficult to introduce a large homogeneous patch of some other land use type such as vegetation. The combined use of RS and spatial metrics leads to new levels of understanding of how urban areas grow and change (Herold et al., 2005) for better planning and sustainable management of natural resources in the region.

Objective: The objective of this paper is to analyse the changes in landscape structure and quantify the spatio-temporal urbanisation pattern in Greater Bangalore using spatial metrics. This involves:

• Analysis of land use dynamics during 1973 to 2010.
• Understanding the agents of sprawl with the developmental pattern in different localities of the city.
• Environmental consequences of drastic land use changes in the region.