Study Session 5 Urbanisation: Trends, Causes and Effects
研究环节 5 城市化:趋势、原因和影响
Introduction
介绍
More than half of the world’s population lives in urban areas. Due to the ongoing urbanisation and growth of the world’s population, there will be about 2.5 billion more people added to the urban population by 2050, mainly in Africa and Asia. The world’s urban areas are highly varied, but many cities and towns are facing problems such as a lack of jobs, homelessness and expanding squatter settlements, inadequate services and infrastructure, poor health and educational services and high levels of pollution.
世界上一半以上的人口生活在城市地区。由于持续的城市化进程和世界人口的增长,到 2050 年,城市人口将增加约 25 亿,主要集中在非洲和亚洲。世界城市地区千差万别,但许多城镇都面临着失业、无家可归和寮屋定居点扩大、服务和基础设施不足、卫生和教育服务差以及污染严重等问题。
In this study session, you will learn about the trends in urbanisation and the causes of urban growth. You will also learn about the demographic, health, environmental and social consequences of urbanisation.
在本次学习中,您将了解城市化的趋势和城市增长的原因。你还将了解城市化对人口、健康、环境和社会的影响。
Learning Outcomes for Study Session 5
第 5 节学习成果
When you have studied this session, you should be able to:
学习完本课程后,您应该能够:
5.1 Define and use correctly all of the key words printed in bold. (SAQs 5.1 and 5.2)
5.1 定义并正确使用所有以 粗体打印的关键词。(SAQ 5.1 和 5.2)
5.2 Describe the global and local trends in urbanisation. (SAQ 5.3)
5.2 描述全球和地方城市化趋势。(SAQ 5.3)
5.3 Explain the main causes of urban growth. (SAQs 5.1 and 5.2)
5.3 解释城市增长的主要原因。(SAQ 5.1 和 5.2)
5.4 Describe the main positive and negative impacts of urbanisation. (SAQ 5.4)
5.4 描述城市化的主要积极和消极影响。(SAQ 5.4)
5.1 Urbanisation trends
5.1 城市化趋势
In Study Session 2 you learned about the overall trend in global population growth. Most of this increase is taking place in urban areas. Urbanisation is an increase in the number of people living in towns and cities. Urbanisation occurs mainly because people move from rural areas to urban areas and it results in growth in the size of the urban population and the extent of urban areas. These changes in population lead to other changes in land use, economic activity and culture. Historically, urbanisation has been associated with significant economic and social transformations. For example, urban living is linked with higher levels of literacy and education, better health, lower fertility and a longer life expectancy, greater access to social services and enhanced opportunities for cultural and political participation (UNDESA, 2014). However, urbanisation also has disadvantages caused by rapid and unplanned urban growth resulting in poor infrastructures such as inadequate housing, water and sanitation, transport and health care services.
在第 2 节学习中,您了解了全球人口增长的总体趋势。这种增长大部分发生在城市地区。 城市化是城镇人口数量的增加。城市化主要是因为人们从农村地区迁移到城市地区,它导致城市人口规模和城市地区范围的增长。这些人口变化导致了土地利用、经济活动和文化的其他变化。从历史上看,城市化与重大的经济和社会转型有关。例如,城市生活与更高的识字率和教育水平、更好的健康状况、更低的生育率和更长的预期寿命、更多的社会服务获得机会以及更多的文化和政治参与机会有关(UNDESA,2014)。然而,城市化也存在缺点,因为快速和无计划的城市增长导致基础设施落后,例如住房、水和卫生设施、交通和医疗保健服务不足。
5.1.1 Global trends in urbanisation
5.1.1 全球城市化趋势
In 1960, the global urban population was 34% of the total; however, by 2014 the urban population accounted for 54% of the total and continues to grow. By 2050 the proportion living in urban areas is expected to reach 66% (UNDESA, 2014). Figure 5.1 shows the change in the rural and urban populations of the world from 1950 through to projected figures up to the year 2050.
1960 年,全球城市人口占总人口的 34%;然而,到 2014 年,城市人口占总人口的 54%,并且还在继续增长。到 2050 年,城市地区的居民比例预计将达到 66%(UNDESA,2014 年)。图 5.1 显示了从 1950 年到 2050 年预测数字的世界农村和城市人口的变化。
Figure 5.1 Urban and rural population of the world, 1950–2050. (UNDESA, 2014)
图 5.1 1950-2050 年世界城市和农村人口。(联合国经济和社会事务部,2014 年)
From Figure 5.1, in which year did the number of people living in urban areas first exceed the number living in rural areas?
从图 5.1 可以看出,城市居民人数在哪一年首次超过农村居民人数?
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The process of urbanisation affects all sizes of settlements, so villages gradually grow to become small towns, smaller towns become larger towns, and large towns become cities. This trend has led to the growth of mega-cities. A mega-city is an urban area of greater than ten million people. Rapid expansion of city borders, driven by increases in population and infrastructure development, leads to the expansion of city borders that spread out and swallow up neighbouring urban areas to form mega-cities. In 1970, there were only three mega-cities across the globe, but by the year 2000, the number had risen to 17 and by 2030, 24 more mega-cities will be added (see Figure 5.2).
城市化进程影响到各种规模的定居点,因此村庄逐渐发展成小城镇,小城镇变成大城镇,大城镇变成城市。这一趋势导致了特大城市的增长。特大城市是指人口超过 1000 万的城市区域。在人口和基础设施发展的增长推动下,城市边界的快速扩张导致城市边界的扩张,这些边界向外扩展并吞噬了邻近的城市地区,形成了特大城市。1970 年,全球只有 3 个特大城市,但到 2000 年,这个数字已经上升到 17 个,到 2030 年,将再增加 24 个特大城市(见图 5.2)。
Figure 5.2 The top mega-cities in the world in 1970, 2000 and 2030. (UNDESA, 2014)
图 5.2 1970 年、2000 年和 2030 年世界顶级特大城市。(联合国经济和社会事务部,2014 年)
From Figure 5.2, in Africa how many mega-cities are predicted to exist by 2030 and how many have already existed since the year 2000?
从图 5.2 可以看出,到 2030 年,非洲将有多少个特大城市,自 2000 年以来已经有多少个特大城市?
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The global trend in urbanisation is not the same in all parts of the world. Asia and Africa currently have the highest rates of urbanisation. Figure 5.3 shows a comparison of trends in more or less developed regions of the world.
全球城市化趋势在世界各地并不相同。亚洲和非洲目前的城市化率最高。图 5.3 显示了世界或多或少发达地区的趋势比较。
Figure 5.3 Trends in urban population growth, comparing more and less developed regions. The graph shows the proportion of the total population living in urban areas.
图 5.3 城市人口增长趋势,比较较发达和欠发达地区。该图显示了居住在城市地区的总人口的比例。
In Figure 5.3, how would you describe the trends in urban growth in more and less developed regions during this century?
在图 5.3 中,您将如何描述本世纪较发达和较不发达地区的城市增长趋势?
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5.1.2 Urbanisation in Ethiopia
5.1.2 埃塞俄比亚的城市化
Ethiopia is one of the least urbanised countries in the world today, and only 18% of its population lives in urban areas (JMP, 2014). In common with many other developing countries, however, this pattern is changing (Figure 5.4). Ethiopia’s urban growth rate is more than 4.0% per year, which places it among the highest in Africa and the world (MWUD, 2007).
埃塞俄比亚是当今世界上城市化程度最低的国家之一,只有 18% 的人口居住在城市地区(JMP,2014 年)。然而,与许多其他发展中国家一样,这种模式正在发生变化(图 5.4)。埃塞俄比亚的城市增长率每年超过 4.0%,在非洲和世界上名列前茅(MWUD,2007 年)。
Figure 5.4 Changing proportion of urban and rural population in Ethiopia from 1950 to 2050 (estimated from 2014 onwards). (UNDESA, 2014)
图 5.4 1950 年至 2050 年埃塞俄比亚城市和农村人口比例的变化(从 2014 年开始估计)。(联合国经济和社会事务部,2014 年)
The rapid increase in urban populations has meant that peri-urban areas are growing much more quickly than formal urban centres. Peri-urban areas are those areas immediately around a town or city. They are areas in transition from countryside to city (rural to urban), often with undeveloped infrastructure, where health and sanitation services are under pressure and where the natural environment is at risk of degradation.
城市人口的快速增长意味着城郊地区的增长速度比正规城市中心快得多。 城 郊地区是指紧邻城镇或城市的地区。这些地区正处于从农村向城市(农村到城市)的过渡期,通常基础设施不发达,卫生和卫生服务面临压力,自然环境面临退化的风险。
Defining the boundaries of urban, peri-urban and rural areas is not straightforward. They do not neatly separate themselves by lines on a map. On the contrary, the sprawling nature of urban development means that the areas merge into each other. The lack of a clear boundary can make it difficult to assess the size of towns by their population or geographical area. However, judgements have to be made and, for planning and administrative purposes, data on population size are collected. Table 5.1 shows the number of towns and cities in Ethiopia by population in 2007, the most recently published data.
定义城市、城郊和农村地区的边界并不简单。他们不会在地图上用线条整齐地分开。相反,城市发展的蔓延性质意味着这些地区相互融合。缺乏明确的边界会使难以根据人口或地理区域评估城镇的规模。但是,必须做出判断,并且出于规划和管理目的,收集有关种群规模的数据。表 5.1 显示了 2007 年埃塞俄比亚按人口计算的城镇数量,这是最近公布的数据。
Table 5.1 Numbers and sizes of urban settlements in Ethiopia. (Adapted from MWUD, 2007)
表 5.1 埃塞俄比亚城市定居点的数量和规模。(改编自 MWUD,2007 年)
Population of urban settlement 城市聚落人口 | Number 数 |
Up to 2,000 最高 2,000 | 171 |
2,000 to 4,999 2,000 至 4,999 | 339 |
5,000 to 19,999 5,000 至 19,999 | 310 |
20,000 to 49,999 20,000 至 49,999 | 79 |
50,000 to 99,999 50,000 至 99,999 | 14 |
100,000 to 200,000 100,000 至 200,000 | 8 |
Above 200,000 200,000 以上 | 4 |
Total 总 | 925 |
Of the four cities with a population of more than 200,000, by far the largest is Addis Ababa. In 2007, the population of Addis Ababa was more than 3 million, which amounted to about 25% of Ethiopia’s urban population (MWUD, 2007). The next-largest city, Dire Dawa, had only 293,000 occupants at that time. The impacts of urbanisation are generally much more evident in the capital than in other towns and cities.
在人口超过 200,000 的四个城市中,迄今为止最大的是亚的斯亚贝巴。2007 年,亚的斯亚贝巴人口超过 300 万,约占埃塞俄比亚城市人口的 25%(MWUD,2007 年)。第二大城市 Dire Dawa 当时只有 293,000 名居民。城市化的影响在首都通常比其他城镇要明显得多。
5.2 Causes of urbanisation
5.2 城市化的原因
Urbanisation in the developing world occurs for two main reasons: the natural increase of population and rural to urban migration.
发展中国家的城市化有两个主要原因:人口的自然增长和农村向城市的迁移。
5.2.1 Natural increase of population
5.2.1 人口自然增长
From Study Session 2 you will know that the population is increasing in developing countries. This natural increase is a significant cause of the growing urban population.
从第 2 节学习中,您将了解到发展中国家的人口正在增加。这种自然增长是城市人口增长的重要原因。
Explain what is meant by natural increase of population.
解释人口自然增长的含义。
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As birth rates decline over time, according to the demographic transition model, the role of natural increase in determining the pace of urban population growth becomes less important in comparison to migration.
随着出生率随着时间的推移而下降,根据人口转型模型,与移民相比,自然增长在决定城市人口增长速度方面的作用变得不那么重要。
5.2.2 Rural to urban migration
5.2.2 农村向城市迁移
In developing countries, urbanisation usually occurs when people move from villages to settle in cities in hope of gaining a better standard of living. The movement of people from one place to another is called migration. Migration is influenced by economic growth and development and by technological change (Marshall et al., 2009) and possibly also by conflict and social disruption. It is driven by pull factors that attract people to urban areas and push factors that drive people away from the countryside.
在发展中国家,城市化通常发生在人们从农村搬到城市定居以期获得更好的生活水平。人们从一个地方到另一个地方的迁移称为 迁移。 移民受到经济增长和发展以及技术变革的影响(Marshall et al.,2009),也可能受到冲突和社会动荡的影响。它是由 吸引人们到城市地区的拉动因素 和 驱使人们远离农村的推动因素 驱动的。
Employment opportunities in cities are one of the main pull factors. Many industries are located in cities and offer opportunities of high urban wages. There are also more educational institutions providing courses and training in a wide range of subjects and skills. People are attracted to an urban lifestyle and the ‘bright lights’ of city life. All of these factors result in both temporary and permanent migration to urban areas.
城市就业机会是主要拉动因素之一。许多行业位于城市,并提供高城市工资的机会。还有更多的教育机构提供各种学科和技能的课程和培训。人们被城市生活方式和城市生活的 “明亮灯光 ”所吸引。所有这些因素都导致了向城市地区的临时和永久迁移。
Poor living conditions and the lack of opportunities for paid employment in rural areas are push factors. People are moving away from rural areas because of poor health care and limited educational and economic opportunities as well as environmental changes, droughts, floods, lack of availability of sufficiently productive land, and other pressures on rural livelihoods.
恶劣的生活条件和农村地区缺乏有偿就业机会是推动因素。由于医疗保健差、教育和经济机会有限,以及环境变化、干旱、洪水、缺乏足够生产性土地以及农村生计面临的其他压力,人们正在离开农村地区。
Rural to urban migration can be a selective process, as some types of people are more likely to move than others. One of the factors involved is gender, because employment opportunities vary greatly with different jobs for men and women. Another factor is age. Young people are more likely to move to towns, with more elderly people and children left in rural areas. Selectivity in migration affects the population in both the rural and the urban areas. If more men move to towns and cities than women, this leaves a predominantly female society in rural areas.
农村到城市的迁移可能是一个选择性的过程,因为某些类型的人比其他类型的人更有可能迁移。所涉及的因素之一是性别,因为男性和女性的就业机会因工作而异。另一个因素是年龄。年轻人更有可能搬到城镇,而更多的老人和儿童留在农村地区。迁移的选择性会影响农村和城市地区的人口。如果搬到城镇的男性多于女性,那么农村地区就会出现一个以女性为主的社会。