Settlements are sparse in the Amazon basin.

Answer: Because the physical conditions of the Amazon basin are unfavourable for human habitation.

• The region is covered with dense evergreen forests that are difficult to clear and to move through.
• The climate is hot and humid throughout the year with very heavy rainfall, which is unhealthy and favours insects and diseases.
• Much of the land is low-lying, marshy and flooded by the rivers, and the soil is not very fertile because the heavy rain washes away nutrients.
• Transport and communication facilities are poor. Hence only small, scattered (dispersed) settlements are found, mostly along the rivers.