Population density is defined as the number of persons that occupy a fixed area of land (square kilometer). Population density is an important index that shows the concentration of population in a specific area.
A simple method to calculate the density of the population is to divide the total population of an area by the total area of land in which the population is confined. It is usually, measured in persons per sq. km.
Density of Population = Total population / Total area
For example, area of region X is 100 sq. km and the population is 1,50,000 persons. The density of population is calculated as:
Density = 1,50,000 / 100 = 1,500 person/sq. km
Four geographical factors affecting the distribution of population in the world are:
1. Availability of Water: It is the most important factor for life. So, people prefer to live in areas where fresh water is available. For e.g., people live in New Delhi or nearby areas because they receive fresh water easily.
2. Land Forms: People prefer to live on flat plains and gentle slopes. E.g. : Most of the Indian population lives in the central plain areas.
3. Climate: An extreme climate is unfavourable for any living being. Thus, people prefer to live under moderate climatic conditions. For e.g., people in India, at a higher rate live in areas where they find the climate more salubrious and comfortable.
4. Soil: Fertile soils are important for agricultural and allied activities. Thus, this is the reason why so many people live in the states like Punjab and Haryana.