In the upper course, the channel is very narrow and very shallow. By the middle course, the channel becomes wider and deeper usually over 1 m. By the lower course, the channel becomes wider still and the channel is much deeper.

Find out more about the cross profile of a river.

Saltation

Find out more about river transportation.

A valley cross-profile includes the channel, the valley floor and the sides of the valley.

Find out more about the cross profile of a river.

The gradient of the long profile becomes more concave as vertical erosion reduces.

Find out more about the long profile of a river.

Examples include:

• restricts economic development as certain land uses are prohibited
• if land cannot be used for building the current housing shortage will continue
• through building elsewhere habitats may be lost
• it is very difficult to implement retrospectively where urban development has already taken place on the floodplain.

Find out more about soft engineering.