Population Density is a quantitative measure that presents a ratio between the population of a region and its corresponding total geographical area. Researchers use population density for comparative studies in demography or population study. Further, the population density also helps us to understand the population-resource relationship. It assists in getting a better understanding of the spatial distribution of population in relation to land. There are various types of population density.
TYPES OF POPULATION DENSITY
1. Arithmetic Density
- It is the simple ratio between the population and total geographic area.
- Further, arithmetic density indicates the number of persons residing per unit area on the earth’s surface.
- It is a crude indicator of population pressure on environment.
2. Physiological Density
- It is the ratio between total population & total arable land.
- That is to say, how many people live per square kilometer of cultivable land.
- To clarify, arable land represents the land area which includes the area under pastures and meadows. Arable land needs improvement to make it cultivable but presently, it is not cultivable.
- It shows the correct picture of human pressure on land.
3. Agricultural Density
- Concept of agricultural density was introduced by G.T. Trewartha.
- It is the proportion of total population working in agricultural activities to total cultivable land. Therefore, it is a better form of physiological density.
- To clarify, please note that cultivable land is land available and ready for cultivation unlike the arable land.
- It is expressed in the terms of agricultural population per unit of cultivated area.
4. Economic Density
- It is the ratio of the total population to the total economic resource base of a region or country.
- Economic resources include those resources which we use for economic development. For example, agricultural, industrial, minerals, soils ,forests and other biotic and abiotic resources are all economic resource.
- In other words, it shows the resource abundance or scarcity in a certain region.
5. Nutrition Density
- Nutritional density is the proportion of the total population with the total area under food crops. There are many uses of nutrition density.
- Firstly, It is a good indicator of availability of food resources to people.
- Secondly, the policy makers can estimate if the food resources are overused or underused.
- Ultimately, the researchers can use the trends in nutrition density to assess the risk of famines.
- Dobby used this index as a comparative measure in his study of South-East Asia.
To sum up, one can say that population density measurement is a key quantitative measure for assessment of pressure of population on resources. So, a researcher must know the different types of population density. However, the use of the these type of population density in research depends on the purpose and objective of the research. Above all, population density is a simple indicator of analyzing the population-resource relationship.
Dr. Nisha is an Assistant Professor of Geography at Kamala Nehru College, University of Delhi.