Suspension – Fine, solid material held in the water while the water is moving

To remember the meaning of the term Suspension, use the following mnemonic:

The rust on the suspension (suspension) bridge was all removed by the maintenance team and the small particles were held in the water.

The graph above shows how the speed at which water is flowing (velocity) and the size of the particles suspended in the water affect the point at which the particles are deposited (settle at the bottom of the river).

As an example, a particle measuring 0.1cm settles at a water speed of about 1cm per second. But a particle measuring 1cm (ten times bigger) settles when the water is moving at around 10cm per second.

This means that particles of different sizes are deposited at different distances along the course of a river, the smallest particles falling to the bottom at the river's slowest point, usually where it meets the sea or a large lake.