phisical and political map of america

Phisical and political map of asia

main migration waves

On a national scale or place, the population can increase or diminish, besides for the natural movements, for the migratory movements, which are the human displacements of long duration of a place of origin to other one of destination. Inside the migratory movements we can distinguish two principal components depending on if the subject goes to a place or goes out of him. This way when the individual leaves his place of origin it is assessed as emigrant, whereas when it comes to the place of destination she is considered to be an immigrant. The third component exists inside the migrations, which one produces when individuals emigrated return spent a time to his place of origin, naming them returned

 

Synoptic chart of Spanish political system.

 

Spanish population pyramid

A population pyramid is a graph that representing the structure of the population into age groups and sex groups .

To make a population pyramid  need to know the number of its inhabitants, expressed in percentages.

population density

Population density (in agriculture standing stock and standing crop) is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans. It is a key geographic term.

model of population cycle

The model of demographic transition progresses in four stages:

-Old or preindustrial demographic regime: it is characterized by high mortality rates and birth rates.

-First transition: Keep the high birth rate, but mortality drops.

-Second transition: the birth rate begins to decline, but mortality is still down more slowly.

-Modern demographic regime: Mortality rates and very low birth.