5. Look carefully at the diagram in Figure E. a) What is a drainage basin? b) Make your own copy of the diagram and label the water sources, mountain tributaries, main river, confluence and watershed.

a) A drainage basin is the area of land drained by a river and its tributaries. It is separated from neighbouring drainage basins by higher land called a watershed.

b) Labels for the diagram:

• Water sources: the places where the tributaries begin, usually in the mountains or uplands.
• Mountain tributaries: the smaller streams and rivers flowing down from the mountains.
• Confluence: the point where two rivers or a tributary and the main river meet.
• Main river: the largest channel flowing through the centre of the drainage basin towards the sea.
• Watershed: the high land around the edge of the drainage basin, separating it from neighbouring basins.