Bangalore over the years has grown as a robust technology hub, and has been ever-growing in terms of urban space with its inhabitants. Bangalore with its rich flora and renowned botanical gardens, is rightly called Garden City of India. Bangalore city bagged the Central Government sponsored "Indira Priyadarshini Vruksha Mitra" award in the late 1980 in recognition of its extensive green cover. But today, lung space is shrinking in the city and core areas have lost green cover with increase in concrete structures. Sustainable land management is a central challenge here. This metropolitan should ensure growing supply of food and other resources to increasing population. Ironically, these agricultural and plantations lands are being victimized for the growth of Bangalore metropolitan. Bangalore is also known for its lakes which are havens of ecology. Though many of these lakes are artificial tanks, they play a leading role in providing home for varieties of habitats and for recharge of the underground water with which the city's demand for water is being met. But loss of these lakes are also debated and attributed to rampant urban growth. Urban ecology loss has serious consequences on the microclimate of the city and indirectly affects the health of its population. A scientific way of arguing for the urban ecology is through land transformation. Land transformation denotes to qualitative change in land, the act of change of form, shape, structure, appearance or nature of land that have put into some use. Loss of ecology is primarily traceable to land transformation through fragmentation of natural habitat and has often vandalized by urban sprawl. The comparison of sprawl can be with disease process, calling it cancerous growth or a virus (DiLorenzo, 2000). Land use/Land cover study has been attracted a great deal of attention in urban geography. But land transformation is a function and a subcomponent of land use which could quantify the interchange in the functionality of land.
The prime objective of the study is to account the geographical spread of ecological areas especially agricultural plantations, forests and lakes with in Bangalore. Through satellite image processing techniques to assess the spatio-temporal transformation to these ecological areas, categorizing and quantifing transformations and predicting the future threat of ecological areas spatially as well as temporally.
The technological advances in remote sensing products and Digital Image Processing software are surely blessing to analyze bio-geo degradations and urban ecological stress studies. The Indian Topographic Maps of 1:50,000 scale are used as the base line data for comparison. Indian Remote Sensing Satellite (IRS) I C imagery with LISS IV data of 23.8 meter spatial resolution is obtained for two time periods i.e., 2001 and 2005. The transformations are phased into two slots, Phase-1 studies the transformation between 1970 and 2001 which could be inferred by comparing the topographic map and satellite imagery of the year 2001. Phase-II transformations are traced by comparing the satellite imageries of 2001 and 2005. Various classes of transformation are obtained by analyzing the spectral reflectance curves and values. The result gives a clear delineation of different classes of transformation.
3.1. Phase-I. Transformation of Forest
BangaloreUrban District covers an area of 2184.14 sq.km. The forest area spreads to an aerial extent of 64.61 sq.km in the year 1975 in which good belts of Reserve forest and State forest can be seen. There is 9.53 sq,km of Reserve forest and 55.08 sq.km of State forest present in the year 1975. Satellite image of 2001 reveals that, the forest cover accounts only 44.25 sq.km, which confers a loss of 20.36 sq.km of natural vegetation. It also depicts that the loss are converted into built up environs, attributing to the urban sprawl and encroachments of urban built-up structures. …