The territorial distribution of the population is the result of the spatial distribution of population and the formation of a network of settlements for a certain period of time. The degree of the population of a particular area is determined by the population density (bp), which is a permanent population, per unit area.
Along with the above measure of the density of the population uses other when in the formula P / Q is taken into account only one part of the p or q. For example, the density of the urban and rural population alone, the population density per unit area of arable land. Measures the density of the urban population is one of the manifestations of urbanization - urban concentration, the process of concentration of population in urban areas.
In the largest cities of the world at the beginning of the 90s. XX century. this is measured in tens of thousands of people per 1 sq. km. km. For example, in Hong Kong (Hong Kong), it is equal to more than 250 thousand in Paris and Calcutta - more than 33 thousand, etc. For a more accurate indicator of urban concentration used "purified density" - of the total area of urban settlement are deducted territories occupied by forest parks, fields, vacant lots and other uncultivated areas (in some urban areas, they account for up to 50% in urban areas). For the purposes of microanalysis often calculate the number of residents per 1 living room, or 1 m. m of living space.
As a result of migration and human activities on the Earth inhabited by almost all suitable for human life space. However, the uneven distribution of the population - along with extensive densely populated areas with high population density are undeveloped area, covering an area of about 15% of the total land area.
By unpopulated areas include polar regions (permanent settlements are located just south of 78 degrees north latitude and north of latitude 54), high-altitude region (almost all mountain areas located over 5,000 m above sea level), the bulk of the giant deserts of Central and South-West Asia and North Africa.
At the same time, in the most densely populated areas of the world that make up about 7% of the land is concentrated more than 70% of the population of the planet. This is the first of the ancient irrigation in the valleys of the major rivers of South, Southeast and East Asia, the valley of the Nile in Africa and the industrial areas of Europe and North America. An overwhelming majority (80%) live in the plains, in the lowlands and uplands within 500 meters, the area of which is only 28% of the total land area. In Europe, Australia and Oceania in areas home to more than 90% of the population.
In Africa and South America, much of the population lives in areas located at an altitude of 500-1500 m (respectively, 35.6 and 27.5%). In Bolivia, Afghanistan, Ethiopia, Mexico, Peru, over two-thirds of the population located in areas with a height greater than 1000 m (in general in the world in these areas home to 8% of the population).
In the Netherlands, Poland, France, Japan, the U.S., almost all the settlements do not rise more than 500 meters (in the Netherlands, almost 40% of the population lives in areas protected by levees, located below sea level).
In the 200-kilometer strip along the sea coasts, constituting 16% of the land, half of the world population is concentrated.
The average density of population in the world is increasing in proportion to its population. In 1900 it was equal to 12 people per 1 sq. km. km inhabited parts of the world in 1950 - 18, in 1992 - 40. The firmness of the rural population is growing much more slowly (respectively, 10.5, 13, 16 people per 1 sq. km.). In most industrialized countries, rural population density tends to decrease.
Sometimes the density of population is very different in different regions of the same country. Thus, in the Soviet Union disintegrated in the average population density of European exceed 35 persons per 1 sq. km. km, and the Asian side was only about 4.5 people.
Within regions of the world population density is also not the same. For example, in Europe (excluding certain "dwarf" states, such as Monaco, where the population density reaches 15.5 million people per 1 sq. km.), The highest average population density (200-350 persons per 1 sq. km.) In The Netherlands, Belgium, Germany and the UK. Low population density (2-15 people per 1 sq. km.) Characteristic of Iceland, Norway and Finland.
The population density is slightly higher in Asia than in Europe, and among the rural population - nearly 2.4 times. Now concentrated in Asia 7/10 of the total rural population. The highest density (200-1000 people. Per 1 sq. km.) In Bangladesh, Japan, Lebanon, Sri Lanka and India. The density of the population in Mongolia, Saudi Arabia and Oman only 1 to 5 persons per 1 sq. km. km. Strong fluctuations in the density observed in the large countries - China, India, Indonesia and others.
In Africa, the highest population density in Rwanda and Burundi (200-300 or more people per 1 sq. km.), The lowest in the Western Sahara, Namibia, Botswana, Libya and Mauritania (1-2 people per 1 sq. km.). For some countries, the continent is characterized by large populations of contrasts (eg, Egypt).
In America, which has almost the same average density as Africa, rural population density is 2.5 times less than that due to a high proportion of the urban population. The highest average density observed in Central America (for example, in El Salvador and Jamaica - 250-300 people per 1 sq. km.), And the lowest - in Canada (this is due to its extremely low population of polar territories), Brazil, and Peru (3 - 15 people).
Very low population density in Australia and Papua - New Guinea (2-7 people per 1 sq. km.).
Small islands sometimes have a very high population density. Among relating to Africa, Mauritius island is densely populated (575 people per 1 sq. km.), In the Mediterranean - Malta (1,105 people) in the Caribbean - Barbados (578) and others. Sufficiently high density of the population in many countries of Oceania (more than 150 persons per 1 sq. km.).
3. Types and factors of migration
According to tradition in the national methodology, types of migration are due to stay at the place of entry of migrants and specific in nature. The main types of migration include:
1) episodic;
2) Pendulum (shuttle);
3) seasonal;
4) irrevocable;
5) forced;
6) illegal.
Episodic migration - this is business, tourism, recreation, etc. travel without a regular temporary nature. Their importance to the transition to a market economy has increased significantly. In scale this type of migration is superior to all others, even though its significance, especially demographic, significantly inferior to them. Currently, he studied with the exception of foreign tourist visits, very weak.
Pendulum (shuttle) migration - regular, daily or weekly trip to the public from residences to places of work (study) and back. Their main areas: the village - to the city from a small town - in a major. Significant commuting occurs in suburban areas of major cities, as well as in the area of small towns in rural areas of urban areas. In general, in the suburban areas of cities formed area of sustainable commuting, its important condition - the development of transport. This type of migration is a major source of labor in the cities (almost 20% of the needs of large cities in the labor force is covered by commuting), increases the efficiency of the use of highly skilled manpower through the replenishment of workers with lower skills, expanding the zone of direct influence of large cities - centers of material and spiritual culture, attaching the population, mainly rural to urban studies and way of life, social mobility, creates a wider choice of profession and employment, promotes the development of new forms of settlements, which combine elements of urban and rural settlement.
The negative features of commuting - the overhead of free time, the amount of travel to and from work is "transport fatigue", leading to a decrease in productivity.
Seasonal migration - moving mostly economically active population to places of temporary work and residence for a period of several months and still be able to return to their places of permanent residence. On the one hand, the seasonal migration provide the participants obtain better income than they have in the ground breaking, but on the other - meeting the needs of production, experiencing shortage of manpower. Such migration related to the specific economy of certain regions, dominated the industry in which the demand for labor is not uniform in time. These include primarily agriculture, where in season planting and harvesting labor demand is much greater than in the rest, especially the winter, time. It also includes a seasonal industry for processing of agricultural raw materials, forestry (alloy of work), fishing (offshore fishing), mining and metals (as it relates to work in the mines), etc.