ABSTRACT
The burgeoning population of cities and their evolution into mega- or gigacities, is an on-going process. Cities create opportunities for people on the one hand but present new challenges for sustainable living on the other hand. Urbanisation, though often linked to development, poses several challenges to sustainable development per se. It is a gradual process of accommodating the rising numbers of inhabitants with the passage of time. Cities undergo demographic, morphological, environmental, social, economic and cultural changes over the span of time. As the world’s population increasingly inhabits cities, urbanised areas have become the most rapidly expanding habitat type worldwide. Cities currently represent about 3 per cent of the world’s land usage, but their effects on climate, resources, pollution and biodiversity extend far beyond their municipal borders (Grimm et al., 2008). The land being a fixed entity and almost limited, poses a challenge of accommodating people and their needs. The complex structure and system of a city gets further complicated due to unforeseen and unwanted events both in terms of natural and man-made. It becomes difficult to ascertain the optimum model of growth and management for the cities and their resources. The ecological stress on the city is difficult to evaluate as its ecosystem undergoes a drastic change from its original state. To begin, this chapter introduces the concept and methodology adopted in the book. This chapter focuses upon the concept of the urban green space and its utility. It assesses the economic, social, health and psychological significance of green spaces in a city. The chapter also highlights the quantity and quality of green spaces required in the cities. It also identifies the preferable location of green spaces. Finally, the chapter elaborates upon the concept of a green city and evaluates Delhi as a green city based on people’s perception.
