Human Population

Population is defined as the total number of individuals of a species present in a particular area at a given time.

Demography is the study of population. It mainly deals with the change in population, and the composition and distribution of population.

Population census is the total process of collecting, compiling, and publishing demographic, economic, and social data pertaining to a specific time, for all persons in a country. Population census is conducted every 10 years.

Demographic Cycle

The demographic cycle, also known as the population cycle or Demographic Transition Model (DTM), refers to the evolution over time of the population of a country, region, or other geographical area. Four stages of population change in the demographic cycle were identified by the American demographer Warren Thompson in 1929.

• First stage (high stationary): marked by high birth rates and high death rates, and a relatively low population.
• Second stage (early expanding): uneven population density due to increased urbanization and industrialization.
• Third stage (late expanding): birth and death rates are much lower, resulting in a relatively steady population growth rate.
• Fourth stage (low stationary): characterized by an actual decline in the population of a country, due to an excess of deaths over births.

So, these are the factors responsible for change in population. Population begins to decline when the birth rate is lower than the death rate.