1. Introduction

Urbanisation is a form of metropolitan growth in response to often bewildering sets of economic, social, and political forces and to the physical geography of an area. This could be planned (in the form of townships) or unplanned (organic). Many organic cities are now undergoing redevelopment for economic purposes with new roads, infrastructure improvements, etc. It results in the increase in population, in proportion to the region's rural population. This phenomenona is very rapid in India with urban population growing at around 2.3 percent per annum. The 20th century is witnessing "the rapid urbanisation of the world’s population", as the global proportion of urban population rose dramatically from 13% (220 million in 1900) to 29% (732 million, in 1950) to 49% (3.2 billion, in 2005) and is projected to rise to 60% (4.9 billion) by 2030 (World Urbanization Prospects, 2005). An increased urban population and growth in urban areas is inadvertent with population growth and migration. There are 35 urban agglomerations/cities having a population of more than one million in India (in 2001). Of the 4000 plus urban agglomerations, about 38 percent reside in just 35 urban areas, thus indicating the magnitude of urbanisation. Overall rise in population of urban poor or increase in travel times owing to congestion in road networks are indicators of urban governance and planning. As Indian cities continue to experience urbanization and urban sprawl, the land use (LU) plays a determining role in the quality of land, water and air environment. This pose serious challenges to the decision makers in the city planning and management process involving plethora of issues like infrastructure development, traffic congestion, and basic amenities (such as electricity, water, and sanitation), floods, heat island, loss of aquatic eco-system, carbon footprint, etc. (Kulkarni and Ramachandra, 2006; Ramachandra and Kumar, 2008). Thus, the administration at all levels: local bodies, state government and national government are facing the brunt of rapid urban growth. It is imperative for planning and governance to facilitate, augment and service the requisite infrastructure over time systematically. This requires an understanding of landscape characterisation and urban dynamics with causal factors.

Identifying, delineating and mapping landscapes on temporal scale provide an opportunity to monitor the changes, which is important for natural resource management and sustainable planning activities. Geoinformatics helps in the integration of remote sensing (RS) data with ancillary information from various other sources (population, natural resources, etc.) to arrive at decisions related to development of urban growth. Multi-source, multi-sensor, multi-temporal, multi-frequency or multi-polarization RS data (Arora and Mathur, 2001) with efficient classification algorithms and pattern recognition techniques (Duda, et al., 2000) aid in capturing the dynamics. The classification methods and modelling approaches are very useful in landscape characterisation for addressing the problems of sprawling cities and urban management. The objectives of this work are to understand the landscape dynamics in Greater Bangalore by characterising:

• Direct impervious surface modelling,
• Forest fragmentation modelling and index, and
• Urban growth type modeling to quantify and categorise urban change.