Arithmetic density, also known as real density, is very simply the total number of people divided by the total land area. Physiological density is the number of people per unit area of arable land. This measurement is often used to estimate how long a land and its resources can support its population.

Why is physiological density more meaningful than crude arithmetic density?

Physiological Density

This may be the most helpful way of expressing population density. Physiological density is the number of persons per unit of agricultural land. This measure of density is useful, because it can give us a rough estimate of how many people an area of farmland can reasonably support.

Why do geographers compare arithmetic and physiological density?

Why do geographers compare physiological and arithmetic densities? To understand the relationship between population and resources in a country, geographers examine a country’s physiological and agricultural densities together.

In Egypt, for example, the large difference between the physiological density (2,580 people per square kilometer of arable land) and arithmetic den- sity (75 persons per square kilometer over the entire country) indicates that most of the country’s land is unsuitable for inten- sive agriculture.