The Nile delta has 1000 people per square Kilo meter
Physiological
There are a lot of people spread out this arablew land
Agricultural
There is a lot of farm land and there are a lot of farmers
The amount of people divided in a certain area, it is helpful for people trying to find the population density of a region.
The number of people per unit area of arable land, it is helpful for finding out were the best place to find good farm land
Measures the number of farmers specifically on each unit of farm land, it is helpful because you can find out how many people are farmers and are in agriculture