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Question: Urban Ecology

Answer: Urban Ecology

Key Concepts

After completing this chapter, you will be able to:

1. Explain the factors that allow cities to exist and support their human population.
2. Describe recent trends of rapid urbanization.
3. Describe the structural and functional characteristics of the urban ecosystem.
4. Define the concept of an ecological footprint.
5. Explain the essential elements of urban planning and how it has affected land-use in Canadian cities.
6. List the major kinds of urban pollution and describe their causes and recent trends in Canadian cities.
7. Describe the methods of waste management.
8. Compare the management of solid waste and sewage among Canadian cities.
9. Explain the major elements of urban biodiversity and how it can be better managed through the naturalization of habitats.

Introduction

The Development of Urban Areas
Urban areas are cities, towns, and other places where people live in a compact population. Most urban people are engaged in economic activities that function efficiently in dense populations, such as commerce, education, manufacturing, and services. In contrast, resource-based economic activities, such as cultivating food and harvesting minerals, fossil fuels, timber, or wildlife, occur primarily in rural areas.
Urban areas import energy, food, and materials from the local countryside, as well as from more distant regions of their country, in addition to other nations around the world in an increasingly global commerce. The resource-related connections between cities and rural areas exist at all spatial scales (local, regional, and global) and are an integral but often insufficiently appreciated aspect of urban ecology.

The development of dense habitations (initially small villages) during human cultural evolution began about 10-thousand years ago, when early agricultural practices allowed the production of local surpluses of food (harvests that exceeded the subsistence needs of the farmers themselves). The excess food encouraged the development of specialized occupations that were most efficiently performed in a central place such as a village or town. New societal activities included organized religion and political systems, artisanal manufacturing, and the means of administering these over wide areas through hierarchical economic, political, religious, and military structures.

The first villages were probably supported by both settled agriculture and local hunting-and-gathering activities. By about 9,000 years ago, small farming villages were relatively widespread in some regions, particularly in the Fertile Crescent of the Middle East (see Chapter 24). By 8,500 years ago, that region boasted sizeable walled towns. Similar developments also occurred in China and probably elsewhere in southern Asia.

From these humble beginnings, urbanization of the human population has proceeded apace, and especially rapidly during the past century. Only about 2.5% of the human population lived in towns and cities in 1800, and 5-10% in 1900. Today, about half of the human population lives in urban places, and this is predicted to rise to two-thirds by 2025 (or about 5 billion people). About 90% of this increase in urban populations will occur in less-developed countries (see Chapter 10). Globally, the urban population is now growing about four times as quickly as that of rural areas, largely because of the migration of huge numbers of people from the countryside to built-up areas.

In Canada, about 20% of the population lived in towns and cities in 1871, increasing to 38% in 1900, 63% in 1950, and 81% in 2011 (of which 45% live in cities larger than 750-thousand people; Chapter 11).

In 1750, few cities supported more than 50-thousand people – London was the only one in England, and there were none in North America. In 1830, New York and Philadelphia were the only American cities with a population greater than 100-thousand. By 1910, however, 52 cities in North America supported more than 100-thousand people (New York was the largest, with more than 1 million). In 1950, New York and Tokyo were the only two megacities in the world (that is, having a population greater than 10 million). In 2014, there were 537 cities supporting more than 1 million people, including 35 megacities, of which 29 were in the developing world (Brinkhoff, 2015). The largest megacities are listed in Table 10.5.

No effective discussion of urban population policies has occurred in any country. Consequently, no population policies exist for urban areas in Canada or elsewhere. The key issues are how large should cities be in order to provide people with safe and clean places to live, while also supplying the goods and services that urban areas can deliver most effectively? If the largest cities are considered overpopulated, how can continued population growth be discouraged? Can people be encouraged to move to smaller centres? These and other questions related to urban population policies are extremely controversial, but all will have to be addressed.

(Source: Pustaka Negeri Sarawak, 04 Aug 2021)

Source Link: https://ecampusontario.pressbooks.pub/environmentalscience/chapter/chapter-25-urban-ecology/