The Drainage Basin System

Precipitation INPUT

any source of moisture reaching the ground, rain, snow, frost.

Interception STORAGE

water being prevented from reaching the surface by vegetation.

Surface Storage STORAGE

Water held on the ground surface, e.g. puddles.

Infiltration FLOW/TRANSFER

Water sinking into the soil/rock from the ground surface

Percolation FLOW/TRANSFER

Water seeping deeper below the surface

Ground Water STORAGE

Water stored in the rock.

Transpiration OUTPUT

Water lost through pores in vegetation.

Evaporation OUTPUT

Water lost from ground/vegetation surface.

Surface run-off FLOW/TRANSFER

Water flowing on top of the land.

Through Flow FLOW/TRANSFER

Water flowing through the soil layer parallel to the surface.

Ground Water Flow FLOW/TRANSFER

Water flowing through the rock layer parallel to the surface.

Water Table

Current upper level of saturated rock/soil where no more water can be absorbed.

Watershed

The area of high land forming the edge of a river basin

Source

Where the river begins

Channel

This is where the river flows.

Mouth

Where the river meets the sea.

Confluence

The point at which to rivers meet

Tributary

A small river or stream that joins a larger river.

Drainage Basin

This is the area of land drained by a river and its tributaries.