Explain how natural resources could cause the population distribution in Brazil to change over time

Humans will tend to migrate to area where natural resources are more abundant.

Explanation:

Existence of large number of natural resources massively enhance people's ability to survive, because of this there tend to be a trend which make population tend to be distributed heavily to the area with massive reserve of natural resources (For example, Area with more water source will be seen as more desirable compared to drought area).

This behavior can be applicable to all societies, including Brazil. For people who want to open up new business for example, they have higher chance of obtaining materials with cheaper cost if they move to area with less competition so they can acquire more natural resources. Since new businesses need workers, population of that area will naturally increase because people will move there to obtain jobs.