large boulders and rocks are rolled along the river bed. The exception is during times of flood, when velocity increases and friction is overcome due to higher energy levels. Near the mouth ...

In its lower reaches, the river bed has actually become higher than the level of the surrounding countryside. Water is held in by dikes of ever increasing height, some reaching 30 feet and more.

The NDSA team found that deep scour zones up to 5 metres below the original bed level were observed, particularly between ...

Erosion is the process that wears away the river bed and banks. Erosion also breaks up the rocks that are carried by the river.