Presently 50% of the global population lives in cities which occupy only 3% of the land area and it is expected that the urban population will further rise to 67% in the next 50 years. In developing countries, about 44% of the population currently lives in urban areas, which is likely to increase considerably in the next 20 to 30 years.During the last 50 years, the population of India has grown two and a half times. But the urban population has grown...