INTRODUCTION

Urbanization is a dynamic process involving the spatial and demographic changes leading to the increase in urban area with the concentration of population mainly due to migration [31,3,7,20] and anthropogenic activities.  Problems of urbanisation, which include inadequate housing and infrastructure, lack of basic amenities (water and sanitation), enhanced levels of pollution (water, air and land) are the manifestations of unplanned urbanisation, regions with poor economic base, lopsided urbanisation. This involves radical changes in land uses resulting in the alterations in spatial structure and configurations of the landscape affecting its functional [31,13].  The spatio-temporal analysis of land use dynamics helps in understanding various processes and interactions of the study area. Evaluating these processes that change temporally helps in understanding the complex dynamics that aid in understanding and visulaising the future spatial and temporal changes and in identification of local forces [6,23,24].

Urban population in India is increasing at about 2.3% per annum and 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 [30]. India has been experiencing rapid urbanisation with globalization and consequent opening of markets. There are 48 urban agglomerations (Mega cities, Tier I) having a population of more than one million in India (in 2011). Tier 1 cities have reached the saturation level evident from lack of natural resources (water, electricity, infrastructure),  higher levels of pollution (crossing the assimilative and supportive capacity of ecosystems), having higher traffic bottlenecks, higher crime rates due to burgeoning population. This has necessitated the focus shift from Tier 1 urban areas to Tier 2 cities that offer humongous potential with the scope for meeting the basic amenities with appropriate urban planning. This 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. This is conceivable with modeling and visualization of urban growth using the historical spatio-temporal data. Failing to visiulaise and plan such growth would again lead to urban outgrowth depriving the local population with the basic amenities.

In this backdrop, current study focuses on urban  growth and its forms  and  transition  of  rural  area to  urban  forms in  terms  of  urban  land-use  classes.  Urban  sprawl,  also  known  as  Peri urban area  is  defined  as  a  low-density development pattern  of  urban  growth having various social, environmental disadvantages [4,15,1,28,21]. It is important to characterize urban sprawl in order to develop a comprehensive understanding of the causes and effects of urbanization processes. Urban sprawl is often evaluated and characterized exclusively based on major socioeconomic indicators such as population growth, commuting costs, employment shifts, city revenue change, and number of commercial establishments [10]. However, this approach does not portray the spatial dynamic of urban sprawl. Land use spatial variability and urban sprawl have been monitored by transition patterns of spatial configurations reflecting dynamics of land uses using temporal remote sensing data [9,32,31].  Subsequent contributions  include gradient  analyses, geospatial  tool  applications such as landscape metrics to understand  the process  urban  growth  pattern [5,19,11,31]. Mapping urban areas remains a complex challenge, thus a multitude of indicators have been created in order to characterize landscape structure and landscape pattern. One such indicator is Landscape metrics. Landscape metrics quantify spatial patterning of land use patches of a geographic area [12]. It provides both a quantitative and qualitative data and information on urban forms [31,2,18]. Changes of landscape pattern have been detected and described by spatial metrics which aided in quantifying and categorizing complex landscapes [16,25,17,8,2,31]. Applications of landscape metrics include landscape ecology (number of patches, mean patch size, total edge and mean shape), geographical applications [22], etc.

Tier II twin cities Hublidharwad  was considered for the current analysis and  the  objectives of the study are to (a)  quantify  urban  growth  dynamics considering the administrative boundary with 5 km buffer through Land cover and land use analyses, (b)  to  understand the pattern of urban growth through gradient approach,  and (c)  understand the dynamics of growth using spatial metrics. Such information can support policy-making in urban planning and natural resource conservation.