English
中文Population Geography is the study of spatial variations in distribution, migration, composition and growth, or density, of human numbers on earth. It is important because it links all aspects of human geography together. It is closely associated with demography, which is the study of population characteristics (Revision Notes, 2001). Population is affected by births and deaths, immigration and emigration. However, there are a variety of factors which can affect population geography. These include: environmental factors, for example climate or natural resources; economic factors, for example economic development, and political factors, such as government policies or conflicts. Each of these factors can in turn affect population geography by contributing to the movement or alteration of population in an area. A major influence on population geography is therefore migration.
The last quarter of the twentieth century has been referred to as the age – or era- of migration due to the unprecedented number of persons who are no longer in their countries of birth or ethnic origin (Tsimbos, 2006). Migration has an influence on population geography in all areas of the world. However, it is often a neglected part of population study. Konseiga (2005) explains that despite the striking importance of migration and its socioeconomic and political implications, it is the least studied demographic phenomenon in West Africa. This ‘movement’ can range from global migration between countries to daily commuting, thus it is difficult to define. However, Pacione (2005) states it is the permanent or semi-permanent change of residence of an individual or group of people. Regardless of definition migration has a major impact on population geography; globally or locally in cities or countries.
Any migration is as a result of push forces at the origin and pull forces at the destination. Push factors, which force people to move, are generally negative and can be issues such as lack of job opportunities, agricultural decline, conflict, natural hazards or environmental degradation. For example, economic development is usually associated with population movements from rural areas and small towns into larger cities, as the labour force shifts from agricultural and cottage industry employment into modern manufacturing and service provision (Henderson, 1986). This is usually due to differences in the standards of living between urban and rural locations. Whereas pull factors which encourage people to move include religion, economic opportunity, land availability or political freedom. Mettam and Williams (2001) describe how a demand for labour, due to expanding industry which cannot be satisfied locally, leads to an influx of population. Many Mexicans cross the border into the USA due to these push and pull factors. The push factors include higher unemployment, lower pay and the poorer standards of living and pull factors are the perceived improved conditions in the USA (Nagle, 1998). The US authorities try to prevent this migration as the influx of too many people can be detrimental to their country but it is impossible to guard the entire border.
The consequences of migration, as stated by the sourced Revision Notes (2001), can be divided into 3 categories:
1. Demographic Consequences:
1 Changes in the numbers and distribution of people within a region.
2 Intermarriages are created, leading to a new group of people.
2. Social Consequences:
1 Migration brings different people together leading to conflicts.
2 Migration however also creates understanding between different groups of people.
3 Rural-Urban migration creates ghettoes in cities.
3. Economic Consequences:
1 This depends on the “quality” of the migrants and the economic needs of the origin and destination. Quality refers to skills, age, educational attainment, health etc.
2 In overpopulated areas, emigration is beneficial because it reduces the pressure on the land.
3 In under-populated areas, emigration may slow down development.
The movement of people to and from an area has an immediate impact and these categories all affect the geography of the population in an area. These impacts can be positive or negative and affect both the place where people have emigrated to and the place they have left behind. For example, Germany has gained a source of cheap labour due to a high number of migrants from Turkey. However, some of the migrants can’t speak German and there has also been some racial tension in the past. Currently this is also a growing problem in the UK where, due to a number of countries recently joining the EU, such as Poland and Romania, the attraction of better jobs and an improved way of life is bringing the same positive and negative effects to the UK. With respect to Turkey, or the former non-EU members mentioned, positive consequences to these countries following the migration include the fact that migrants are able to send the money they earn back to their families in their home countries. However, these countries have also lost a large number of their skilled and professional workforce. The geography can be altered by the influx of new languages and culture. An area could be introduced to new languages by immigrants and may be altered to include multiple languages and ethnicity. This was apparent in the study by Kaplan (1994) in Canada which indicated a clear impact of language on population change as a result of the mobility of French and English speakers.
The USA is a country where geographical mobility has long been an important aspect of life and it shapes the population of geography of the country. Here, due to migration, the ethnicity is changing rapidly. Tienda and Morning (2001) state during 1970 and 1995 the Mexican population increased eight-fold. As recorded in 1990 the population of Americans in North American was 4%. Although this figure would be higher if multiple ancestries were not double counted (Tienda and Morning, 2001). Historically people arrived from abroad with the first European colonies in the 16th Century, but now people are increasingly moving internally. More recently between March 1999 and March 2000 43.4 million Americans moved with over half (56 percent) of these moving locally, 20 percent between countries in the same state, 19 percent moving to a different state and only 4 percent coming from abroad (Schachter, 2001). Overall migration rates have not changed but there has been a decrease in the overall percentage of people moving within the same country and an increase in the percentage of people moving between countries. For example, in the USA in 1998 64 percent of all moves were within the same country, compared with 56 percent of all moves in 2000 (Schachter, 2001). It is possible that this could be true for less developed countries where there are a number of pull factors encouraging people to move for perhaps employment reasons or to escape a political conflict. Migration is therefore a key factor in altering the geography of global and local population for a variety of reasons however there are also several other influences which play a part.
Other factors which affect population geography include population composition, distribution and density. These can also be partly affected by migration but there are also other factors which play a part. Nagle (1998) defines distribution as where people are located and density as the number of people per square kilometre. Favoured locations include those with a good water supply and climate. Studies have shown that the distribution of migrant populations tends to concentrate on a limited number of regions in the host country, mainly urban areas (Tsimbos, 2006). This is probably due to increased opportunities here than in more rural areas. Hogan et al (1999) studied the rapid urbanization, from direct migration to Brazil’s Center-West Region to the region’s cities from other regions of Brazil, and rural-urban migration from within the Center-West itself, as a result of migrants’ failure to establish farms in the frontier areas. However, it also states that the region is a major destination for land seeking migrants and therefore the distribution works both ways. As Nagle (1998) states rural to urban migration is a result of differences in standards of living between urban and rural locations, and between regions. The better educated are more likely to find employment in urban areas than in rural areas and so this is another reason for this type of move and change in population geography.
Density can be a measure of how advantaged or disadvantaged an area is. This is because the more attractive places to live will see large numbers of people in small areas due to the availability of employment and amenities, whereas densely populated areas can also be deprived if they become overpopulated and resources cannot cope. It is therefore not a reliable indication of whether a place is advantaged. In the UK population densities are over 1000 per square kilometre in parts of the South East, the Midlands and the North West compared to over 4300 per square kilometre in parts of London (Nagle, 1998). This would be expected as London is the UK’s capital and largest city. However, the North West is the most densely populated region overall. By contrast, parts of Scotland have densities of less than 1 per square kilometre (Nagle, 1998). Scotland is a predominantly rural area with a more severe climate, poorer communications and less job opportunities. It does not necessarily mean that the quality of life is less here, in fact some people move here because they think their quality of life will improve. Obviously if the need for a job was the deciding factor on where to locate then perhaps a more urban area would be more appealing, hence the location of such a large amount of people in London. One country where the less populated regions are definitely not appealing is Egypt. Egypt has one of the most uneven population distributions in the world with up to 95 percent of the population found on less than 5 percent of the land (Nagle, 1998).
Some people see increasing population and population density as a way to economic growth. President Yoweri Museveni, who sees China’s success as an argument that a larger population will trigger economic growth, is being criticised by experts who say big numbers are impoverishing Uganda (Wakabi, 2006). It is immediately apparent that birth and death rates, or mortality and morbidity, have an important influence on the population of an area. The birth and death rates influence the density and composition of an area. Unfortunately it is well known that poorer areas have higher death and birth rates than more developed areas. This high growth rate does not help areas that are already deprived and struggling to cope with the current population number. The sustained high population growth in Uganda is putting pressure on the provision of social services and fuelling poverty (Wakabi, 2006). These people cannot move freely to more prosperous areas because they do not have the means and are sometimes prevented doing so due to political powers. The main reason for this rapid growth is high birth rates. Wakabi (2006) states that each woman in Uganda produces on average seven children; only Niger (at eight children), Guinea Bissau (7.1) and Mali (7.1) have more. The women start giving birth young and continue for a large proportion of their lives compared to developed countries such as the UK.
There has been a large change in the population of the UK since the 1970s. In contrast to Uganda, in the last two decades there has been a very low rate of population growth, due mainly to the collapse of the birth rate (Nagle, 1998). Women are driven more by their careers as they are given the opportunities deprived to those in more disadvantaged countries and are choosing to have children later or sometimes not at all. Nagle (1998) explains there have been two periods of birth rate increase with the larger happening at the turn of the century. This resulted in a rise in the number of people of a pensionable age in the 1960s and 1970s and the dramatic increase in the number of very elderly in the 1980s. The increase in the number of pensioners living longer is having an impact on the pension system and the government is finding it increasingly difficult to pay the UK pensioners as they are providing pensions for longer periods as people live longer. On a more positive note, the demand for goods and services tailored towards older people has increased. This in turn creates jobs and in theory helps the economy. In addition, Nagle (1998) goes on to say, there have been changes in the distribution of the population and its composition in certain areas which have caused a massive redistribution of population away from the largest cities to smaller settlements and more rural areas, and by an acceleration of the North-South drift. Perhaps, again, due to the perception of ‘a better way of life’ in the country.
This life expectancy increase has meant that many countries, including the UK, have become an ageing population. This could be true for many developed countries. Such changes reflect another factor of population geography referred to as population composition. This refers to the characteristics of the population including age, gender, ethnic background, language, occupations and religion (Nagle, 1998). To a certain extent migration can affect the composition of a population by introducing different languages and ethnicities to an area. There is segregation of ethnic minorities in the UK which comprise of 5.5 percent of the population (Pacione, 2005). Cities such as London and Liverpool have contained ethnic populations for many decades but the number of minority residences are growing rapidly due to natural increase and family immigration. However, population composition can also again be affected by birth and death rates. The age structure of Japan has changed dramatically over the past fifty years, largely due to a decrease in birth and death rates. The elderly population has risen from 14.6 percent of the total population in 1995 to 20 percent in 2007. The percentage of young people has steadily declined and in 1995 only accounted for 16 percent. By 2025, Japan’s elderly population will be larger than any other developed country (Nagle, 1998). Their life expectancy is the highest in the world but the population is also shrinking.
There are therefore many factors which affect population geography. All of which appear to be linked in some way. Migration is obviously a key aspect and can influence the density, composition and distribution of population. One of the characteristics of population composition is gender. Tsimbos (2006) states how the sex ratio among the Greek and non-Greek citizens is 96.6 and 120.0 (males per females) respectively. This over-representation is considerably apparent between the ages 15 to 35 and affects the composition of the Greek population considerably. During 1991 to 2001 a small increase in the sex ratio was observed but since the natural growth of the population during this period is negligible, this upward trend can be attributed to immigration (Tsimbos, 2006). The gender composition is therefore affected by migration, indicating its importance in population geography. Tienda and Morning (2001) also state that Mexico’s population composition will be driven by the assimilation of indigenous populations into the national population, a process that is shaped largely by social and economic change, along with internal migration and intermarriage patterns. In the short term however Tsimbos (2006) states that migration has a direct demographic effect on the growth and age-gender composition of the host population through the influx of persons entering the country; in the long term, immigration has indirect effects on the vital rates of the population of the receiving country via changes in the levels and patterns of fertility and mortality.
It can therefore by concluded that the process of migration plays an important part on the influence of population geography in countries all over the world and on a global scale being brought about by a variety of different factors. The main reason most studies seem to suggest for this is poverty and the quest for an improved way of life (Nagle, 1998 and Wakabi, 2006). However, populations are always changing naturally and changes in population are also brought about by changes in birth and death rates, for example the ageing population of Japan and population growth of minority groups which have migrated to new regions. It is therefore apparent that, whilst migration is likely to be the main influence on population geography, there are many other factors which also contribute greatly to changing population all over the world.
