2. Drainage Basin

What is the Drainage Basin?

it drains all of the water which lands on the Earth’s surface

• its an open system (both inputs - precipitation - and outputs - oceans / lakes)

State the features of the drainage basin

1. watershed

2. source

3. confluence

4. tributary

5. mouth

Define the Watershed

the boundary between drainage basins

Define the Source

• the furthest point from the mouth

• where the river starts can be an upland lake, spring or glacier

Define Confluence

the place where two or more streams/rivers meet

Define Tributary

a stream or river flowing into a larger stream or river

Define the mouth

where the rivers enter the sea / ocean or sometimes a lake

How is the density of the drainage basin calculated?

tot. length of channel in drainage basin / tot. area of drainage basin

What density do drainage basins with lots of tributaries have?

high drainage density

What density do drainage basins with few of tributaries have?

low drainage density