martes, 18 de diciembre de 2012
lunes, 17 de diciembre de 2012
sábado, 15 de diciembre de 2012
Population density
Population density is the relation between the number of inhabitants of a place and the surface that this place occupies.
In general it is considered that an area is little populated when it has a density of 10 inha./km2. And it is a very populated
area, if the density exceeds 80 inha./km2.
In general it is considered that an area is little populated when it has a density of 10 inha./km2. And it is a very populated
area, if the density exceeds 80 inha./km2.
Model of population cycle
The model of demographic
transition progresses in four stages:
-Old or preindustrial demographic regime: it is
characterized by high mortality and natality rates. Sometines Mortality rate is
higher than natality rate, therefore there is a negative natural increase.
-First transition: keep the high natality rate, but
mortality decrease, because of andvances in sanitation and health care.
-Second transition: the natality rate begins to
decline, but mortality is still down, so there is balance.
-Modern demographic regime: mortality and natality are
very low and sometimes natality rate falls so much that there is a negative
natural increase.
The model of demographic
transition progresses in four stages:
Suscribirse a:
Entradas (Atom)




