Related chart — urban land area over the past 10, years. This chart shows the change in urban land area dating back to 10, BC. The past 50 years in particular have seen a rapid increase in rates of urbanization across the world.
Are these trends likely to continue? The UN World Urbanization Prospects provides estimates of urban shares across the world through to These projections are shown in the chart — using the timeline you can watch this change over time. Across all countries urban shares are projected to increase in the coming decades, although at varied rates.
In fact, by there are very few countries where rural shares are expected to be higher than urban. Why, when most countries are expected to be majority urban , does the global total just over two-thirds? The other map shown here provides a snapshot overview of how the world is expected to continue to become more urbanized.
It shows, for any given country, whether more people the majority live in urban or rural areas. In , it was predominantly high-income countries across Europe, the Americas, Australasia and Japan who were largely urban. In the chart we see estimates of urban and rural populations in absolute terms, projected through to As of we see that there is around 7. By , global population is projected to increase to around 9.
Using our timeline map of urbanization you can explore how countries are expected to transition from predominantly rural to urban in the coming decades. In the chart we show the relationship between the share of the population living in urban areas y-axis and average income gross domestic product per capita on the x-axis. Here we see a strong relationship between urbanization and income: as countries get richer, they tend to become more urbanized. The link between urbanization and economic growth has been well-documented.
Urbanization is complex, however there are many recognised benefits of urban settings when developed successfully including high-density of economic activity, shorter trade links, utilisation of human capital, shared infrastructure and division of labour.
Is there a causal feedback by which urbanization is also a predictor of future economic growth? The evidence for this is relatively weak — assessments of this effect suggest that countries with a higher initial urban population share do not achieve faster or slower economic growth than countries with a low initial urban population share.
There are many examples — across broad areas of development — which suggest that, on average, living standards are higher in urban populations than in rural. Some examples include:.
Note, however, that it is difficult to infer causality between urbanization and these examples. Since urbanization shows a strong correlation with income, such relationships may instead simply show the effect of higher incomes on electricity access, sanitation, drinking water and nutrition. Furthermore, there can also be significant inequalities within urban areas; this is evidenced by the fact that across many low-to-middle income countries a high share of the urban population live in slum households which lack access to all of the basic resources.
It would be expected that changing where populations live will have an impact on types of employment.
In the chart we see the share of people employed who are in agriculture y-axis versus the share of the population living in urban areas. Here, in general, we see that agricultural employment tends to decline with urbanization. Although this agriculture-urbanization link tends to hold true for most countries, there are a couple of clear outliers.
Sri Lanka, Samoa, and Barbados, for example, appear to show relatively low levels of agricultural employment despite being predominantly rural. For Sri Lanka, this anomaly is explained by low urbanization rates, rather than relatively low levels of agricultural employment — a labour share of just under 30 percent in agriculture is not dissimilar for neighbouring countries in the Asia-Pacific region.
In the case of Barbados and Saint Lucia: low agricultural production and employment is common for many small island states. Definitions of an urban settlement vary widely across countries, both in terms of the metrics used to define them, and their threshold level. The data shown for a given country is its nationally-defined minimum threshold. When we look at the frequency at which a given threshold level is used by a country, we see that and inhabitants are the most frequently adopted by 23 countries each.
However, these ranges vary widely: Sweden and Denmark, for example, use a threshold of only inhabitants whereas Japan adopts a very high threshold of 50, inhabitants.
Some use a variation of population density, infrastructure development, pre-assigned city populations, or in some cases no clear definition. The UN adopts national definitions in its reporting of urban versus rural populations. This means urban populations are often not comparable across countries. Access to adequate sanitation in the form of a private or public toilet shared by a reasonable number of people. Some households may lack only one of the above criteria, whereas others may lack several.
The density of a geographic area is measured on the basis of the average number of people per unit of area for example, the number of people per square kilometre, km 2. But what does urban density mean? Here, again, we encounter the difficulty in agreeing on the standard boundary definition of what constitutes an urban area.
Urban agglomeration is defined by the UN as:. This figure, which shows the urban definition boundaries for Toronto, is used by the UN to demonstrate these differences. Summary More than 4 billion people live in urban areas globally. The UN estimates was the year when, for the first time, more people in the world lived in urban than in rural areas.
Just under 1-in-3 people in urban areas globally live in a slum household. For most of human history, populations lived in very low-density rural settings. Urbanization is a trend unique to the past few centuries. People tend to migrate from rural to urban areas as they become richer. Living standards tend to be higher in urban areas. All our charts on Urbanization Access to electricity, urban vs.
Employment in agriculture vs. Urbanization across the world today. More than 4 billion people — more than half of the world — live in urban areas.
How many people live in urban areas today? Click to open interactive version. How does the share of people living in urban areas vary between countries? In the map shown here we see the share of the population that is urbanized across the world.
How urban is the world? What we know about urban populations and why it matters. How is an urban area defined? Sweden Built-up areas with inhabitants or more and where houses are at most metres apart. Japan Cities defined as shi. In general, shi refers to a municipality that satisfies the following conditions: 1 50, inhabitants or more; 2 60 per cent or more of the houses located in the main built-up areas; 3 60 per cent or more of the population including their dependents engaged in manufacturing, trade or other urban type of business.
India Statutory places with a municipality, corporation, cantonment board or notified town area committee and places satisfying all of the following three criteria: 1 5, inhabitants or more; 2 at least 75 per cent of male working population engaged in non-agricultural pursuits; and 3 at least inhabitants per square kilometre.
Zimbabwe Places officially designated as urban, as well as places with 2, inhabitants or more whose population resides in a compact settlement pattern and where more than 50 per cent of the employed persons are engaged in non-agricultural occupations. Singapore Entire population. Uruguay Cities officially designated as such. Schools, colleges and universities are established in cities to develop human resources.
A variety of educational courses are available, offering students a wide choice for their future careers. People of many classes and religions live and work together in cities, which creates better understanding and harmony and helps break down social and cultural barriers. Cities also have advanced communication and transport networks. However, these many benefits of urban life do not apply to all.
Rapid population increases and unplanned growth create an urban sprawl with negative economic, social, and environmental consequences. In Ethiopia, the rate of urban growth often strains the capacity of local and national government to provide urban residents with even the most basic services of housing, water supply, sewerage and solid waste disposal MWUD, In developing countries, about a third of urban inhabitants live in impoverished slums and squatter settlements UN-Habitat, Slums are urban areas that are heavily populated and have sub-standard housing with very poor living conditions, creating several problems.
Many low-income families gravitate to these informal settlements that proliferate in and around towns. Poverty is one of the most critical issues facing urban areas. Urban poverty degrades both the physical and social environment.
The provision of water and sanitation services to growing urban settlements, peri-urban and slum areas presents critical challenges. The increased demand for water from the growing population can place added stress on already stretched resources. In and around cities, water is commonly in short supply and subject to increasing competition by different users.
Urban growth leads to increasing demand for water for industrial and domestic use, which conflicts with agricultural demands. It is especially difficult to provide water and sanitation services to deprived areas and the poorest people. Many people in these areas live without access to safe drinking water and proper sanitation.
Even where adequate water supplies are available, sanitation and wastewater disposal are often inadequate or missing.
Pit latrines and septic tanks are the usual methods for human waste disposal but they have limited capacity and are not always adequate to cope with the quantity of waste produced by many people living close together.
Overflowing latrines and septic tanks contaminate surface water and create a serious health risk. The lack of these essential services threatens not only the health and the environment of people in slum areas, but also that of people living in formal urban areas. In Africa and Asia most of the urban centres have no sewers at all, which affects rich and poor alike. This is true of many cities with a million or more inhabitants, as well as smaller cities and towns. Urbanisation affects land, water, air and wildlife because of the number of people, the amount of buildings and construction, and the increased demands on resources.
It has impacts on the physical environment in several ways. In developing countries, including Ethiopia, many rivers in urban areas are more like open sewers Figure 5. The lack of sanitation and sewerage systems has a dramatic impact on urban watercourses. People use the rivers to dispose of all their wastes from homes, industries and commercial businesses. Wastewater from human settlements contains organic material and nutrients; industrial wastewater contains many different types of toxic pollutant.
These make the water unsafe for humans to use for many purposes including drinking and irrigation, as well as harming the fish and other animals and plants living in the water. Any changes to the quality of surface water also affects groundwater because they are linked by the processes of the water cycle so pollutants from the surface will infiltrate down and contaminate soil and groundwater as well.
In many towns and cities solid waste management is inefficient or non-existent. Solid waste management means the proper collection, transfer, recycling and disposal of all the solid material we throw away, including plastics, paper and cardboard, food wastes, electrical waste, etc.
It also includes industrial, hospital and institutional wastes which often contain pathogens as well as hazardous and toxic chemicals, which need special care. Urban waste often ends up in illegal dumps on streets, open spaces, wastelands, drains or rivers. This is frequently a problem in peri-urban areas, which are convenient for dumping wastes because of the availability of open space and ease of access from central urban areas.
This can lead to the pollution of groundwater and surface waters which may be used as a source for drinking water. Sometimes the wastes are collected and taken to legalised waste disposal sites but these are not always properly managed to protect water bodies and groundwater. The combustion of solid waste creates yet another environmental problem.
People want to get rid of the wastes and they will burn them in their backyards if there is no collection system Figure 5. Air quality in towns and cities is frequently very poor as a result of air pollution from many different sources Figure 5. These include:. Poor air quality has a significant impact on the health of many urban residents as well as leaving a damaging and unsightly layer of dust on plants, buildings and other surfaces.
Urbanisation can have both positive and negative effects on health. The main benefits are associated with easier access to hospitals, clinics and health services in general. If you live close to these services you can reach a doctor in minutes rather than hours or days, so this improves emergency care and general health. There are also benefits from easier access to sources of information such as radio and television which may be used to communicate information about health to the general public.
For example, women living in towns and cities are more likely to be informed about family planning, which results in reduction in family size and less frequent childbirth, with consequent benefits to general health. However, urban life can also damage your health. Poor environment, housing and living conditions are the main reasons for poor health in urban areas. Contamination of water sources can cause epidemics of waterborne disease. Close proximity to other people can make the spread of many types of infectious disease more likely.
The polluted air can also cause respiratory disease and contribute to premature deaths among more vulnerable sections of the population such as older people and children.
Population movements also put pressure on food supplies and on food distribution. As people migrate to the cities, they tend to use purchased food instead of their own crops and this makes them more vulnerable to changes in food prices. As the population grows and the demand for water and land increases, it becomes difficult to increase food production in a sustainable way.
The increase in urban demand, combined with a loss of agricultural land, means more pressure on rural people to produce food for the growing number of urban people. Furthermore, pollution from urban areas can disrupt food supply. For example, fisheries are often damaged by urban domestic wastes and liquid effluents from city-based industries. Effluent is another word for wastewater that flows out from a source. In several Ethiopian cities, such as Bahir Dar, Hawassa, Bishoftu and others, untreated wastes are dumped into nearby lakes, which can damage the fish stocks Figure 5.
In developed countries, the increase was less than half. Rural to urban migration is happening on a massive scale due to population pressure and lack of resources in rural areas. Often they believe that the standard of living in urban areas will be much better than in rural areas. They are usually wrong. Natural increase caused by a decrease in death rates while birth rates remain high. If you've found the resources on this site useful please consider making a secure donation via PayPal to support the development of the site.
The site is self-funded and your support is really appreciated. What causes urbanisation? Levels of urbanisation in and Related Topics Use the images below to explore related GeoTopics.
0コメント