Green to gray: Silicon Valley of India.

Rapid growth, population concentration and the expansion of urban areas towards peri-urban regions have led to changes in urban structure and composition, and consequently changes in urban ecology. The purpose of this study is to estimate trees in the urban environment through quantification of vegetation cover using multi resolution spatial data supplemented with tree data acquired from field using pre-calibrated GPS. Optimal resolution for extracting trees was attained through fusion of multi resolution (spectral and spatial) data. Results highlight region with spatial extent of 741 sq. km with 9.5 million human population has about 1.48 million trees. Further, urban growth increment is expected to cover 95% of the landscape with paved surfaces by 2020 decreasing vegetation cover while severely affecting the local ecology and environment in addition to human survival.