Human Population

Student Name: Alfonzso Daggett

Catherine Bassett-Touchell

Course: Environmental Science (SCIE210-1503C-01)

Date: August 15, 2015

The Demographic Transition Model is a model that assumes that a country will go from an agricultural to an urban economic base, industrial one, that will decrease in family size and the population growth, meaning the population growth results from better standards of living, education, health care, sanitation and other services, moreover the model explain the transformation of countries from having high death and birth rates to low death and birth rates, The transition started in the eighteenth century in developed countries and continues today, but the less developed countries transition began later and are still in its earlier stages of the demographic transition model.

The Model is based on a change in the crude death rate (CDR) and crude birth rate (CBR) over a time period. The CBR is made by taking the number of birth that a country had in one year, divide it by its population, then multiplying the number by 1000. The CDR on the other hand is made when everything is determined form the (CBR).

There are 4 phases of the demographic transition model, they are listed below:

• Stage I: Death and Birth are very high and population grows slowly with the CDR and CBR. The death rates were mainly due to lack of hygiene and disease. High birth rates were high because more children meant more workers on the farms, which meant survival of the families.

• Stage II: Death rates are very low as a result of improved medicine, nutrition, and sanitation, but the birth rates remain high. This stage had dropping death rate but stable birth rate in the beginning. It had a very high population growth rates, children became more expensive and not able to give back to the family, along with the advanvement of birth control, the CBR was reduced in the 20th...