What are two reasons why population distribution and density patterns are useful to understand

Population distribution and density patterns can be useful to understand because they help to explain how and why people migrate and develop in certain places around the world. These factors influence human migration and development and are therefore important to understand if you seek to understand how the world has developed over time and what are the forces that are driving this development. 

Answermost of the time it would be ground into fine sediment,and sometimes they are carried away from the original location;

Exploration mission 2;