Population Geography is one of the branches of Geography that studies and investigates the reasons why people migrate, changes in their quantity on different parts of the planet Earth, population density, etc. Basically, this science is closely connected with human geography since it unites all branches of this discipline. Moreover, it has many similar aspects with demography that is associated with population characteristics.
Why various parts of our planet are inhabited by a different number of people? Scientists have singled out a great amount of causes for that. To begin with, the quantity of population depends on how many people are born and pass away, immigrate and emigrate. What is more, population geography is also affected by peculiarities of the environment, like climate and natural resources; factors concerning economics, for instance, the level of economic development; and by policies of government and politics. All of these factors can change population geography dramatically. However, the most important impact on population geography makes the migration.
The period from 1975 to 2000 is believed to be the climax time of migration because of the record number of people who moved to other countries that are foreign to them. All regions of the world are affected by the influence of migration. Nevertheless, it happens that most of the scholars neglect this important factor while studying population geography. Konseiga, a famous African researcher, admits that in spite of the obvious importance of migration and its noticeable connection with socioeconomics and politics, still not enough scientists devote their time to study this sensation of demography in the western part of Africa. It is worth mentioning that scholars have not defined this term unanimously. There are different formulations what migration means. Anyway, migration is undoubtedly related to population geography: on a global and local level in small settlements and continents.
As we have already explained, there are many aspects that influence population geography and are somehow interconnected. Apparently, migration is the main factor and by which the density, composition, and distribution of population are strongly affected. The composition of the population includes various characteristics, and one of them is gender. Tsimbos claims that, for example, the quantitative relation between males and females residents is 96.6 and 120.0 among the Greek and non-Greek residents. Such sex ration is especially obvious between the ages 15-35 and is considerably affected by migration.
In 2001 Tienda and Morning stated that population composition of Mexico was changing due to the integration of native inhabitants into the national population. This phenomenon is conditioned by changes in economics and social life. A little bit later Tsimbos mentioned that the migration influences greatly the composition of growth and age-gender of the indigenous population because of the huge stream of those who come into this or that country.
In conclusion, migration should be more studied as it is the most important factor of population geography. Why do people migrate? The answer is poverty and desire to live in more developed countries. Apart from migration, many other aspects like birth and death rates make an impact on the geography of population.