INTRODUCTION

Urbanisation is the physical growth of urban areas as a result of rural migration and even towns or suburban concentration transforming into cities. It occurs as governmental efforts to improve opportunities for jobs, education, housing and transportation. Unplanned urbanisation has serious impacts on the local ecology and on the sustenance of natural resources (Ramachandra et al., 2012). The process of urbanisation and its impacts on natural resources is a universal phenomenon taking place in most parts of India. All Cities in India have been experiencing this bewildering phenomenon involving large scale land use changes with globalisation. Urbanisation is an irreversible process involving changes in vast expanse of land cover and local ecology with the progressive concentration of human population. Rapidly urbanizing landscapes with high population density often face severe crisis due to inadequate infrastructure and lack of basic amenities (Bharath et al., 2012). The  urban population  in  India  is growing at about 2.3% per annum while the global urban population has increased from 13% (220 million in 1900) to 49% (3.2 billion, in 2005) and  is  projected  to  escalate to 60%  (4.9 billion)  by  2030 (Ramachandra and Kumar, 2008). The increase in urban population and changes in the land use is mainly due to migration from other areas.  As per census 2011 there are 48 urban agglomerations in India, which are referred as Mega cities or Tier I with population of more than one million. Earlier studies suggest that Tier 1 cities due to burgeoning population and lack of proper urban planning have reached the saturation level evident from lack of basic amenities, over congestion due to inadequate infrastructure, higher amount of pollutants in the environment, contamination of water, scarcity of water and electricity, increasing crime rates, etc. (Sudhira et al., 2003, Ramachandra et al., 2012).. In this context, there is a need to plan Tier II cities (population less than 1 million) in India to ensure these cities do not face the serious infrastructure an environmental problems as Tier I cities.  Tier II cities offer humongous scope in meeting the demand of urban population. Development of tier II cities entails the provision of basic infrastructure (like roads, air and rail connectivity), adequate social infrastructure (such as educational institutions, hospitals, etc.) along with other facilities. Spatio temporal patterns of land use and land cover (LULC) based on the temporal remote sensing data would aid in understanding and visualization of spatial patterns of urban growth. This would also help in identifying the probable pockets of intense urbanization and its effects such as sprawl, etc.

Urban sprawl refers to excessive unusual growth near the periphery of the city boundary or in the places where there is the absence of planning and availability of basic amenities. Cities need to grow in a planned and phased manner, and ensure a balance between proportion of growth and available resources. However rapid unplanned growth exerts pressure on the natural resources. This unplanned growth is called as Urban sprawl or sprawl. The urban sprawl involves disorganized and unattractive expansion of an urban area into the adjoining boundaries (Ramachandra et al., 2012). Remotely sensed satellite data having a good spatial and spectral resolution acquired over frequent time interval is the most widely used tool (Singh, 1989; Hall et al., 1991; Bharath H A. et al., 2012) to assess the changes in the urbanizing landscape over time and consequent sprawl (if happening). Unifying landscape structural ecology with remote sensing and other geospatial techniques can help in analysing and detecting the temporal changes occurring in larger areas more effectively through quantified landscape patterns (Crews-Meyer, 2002; Sudhira et al., 2003; Ramachandra et al., 2012). Quantification of landscape patterns allows to link spatial patterns with underlying ecological processes to some extent (O’Neill et al., 1988; Bhatta, 2010a; Bhatta et al., 2010b; Müller et al., 2010)  and in understanding the relationship between urban growth and mobility (Zhao et al., 2011). Quantification of patterns and process helps in understanding the landscape dynamics s (Crews-Meyer, 2002; Bender, 2003), monitoring (Lausch and Herzog, 1999), management and planning (Kim and Pauleit, 2007; Lin et al., 2007). Spatial metrics have been widely used to study dynamic pattern with the underlying social, economic and political processes of urbanization (Yu and Ng, 2007; Jenerette and Potere, 2010). Applications of landscape metrics include landscape ecology (number of patches, mean patch size, total edge, total edge, mean shape), geographical applications by taking advantage of the properties of these metrics (Gibert and Marre, 2011; Rossi and Halder, 2010; Ramachandra et al., 2012; Bharath H. A et al., 2012). These studies also confirmed that Spatio-temporal data along with landscape metrics would help in understanding and evaluating the spatio temporal patterns of landscape dynamics required for appropriate management measures.

This communication is based on the analysis of urbanization pattern in a Tier II city, Gulbarga. Main objectives  of the study includes (a)  quantification of temporal urban  growth  in Gulbarga city with 5 km buffer, b) vegetation analysis, c) understanding local growth  variation  using gradient approach and  (c)  model the growth using spatial metrics to understand its dynamics . These information support policy interventions in urban planning and natural resource conservation.