7.1.2. Transportation

River carries rock particles from one place to another. This activity is known as transportation of load by a river. The load is transported in four ways.

♤ Traction -The heavier and larger rock fragments like gravel, pebbles etc. are forced by the flow of river to roll along its bed. These fragments can be seen rolling, slipping, bumping and being dragged. This process is known as traction and the load is called traction load.

♤ Saltation-Some of the fragments of the rocks move along the bed of a stream by jumping or bouncing continuously. This process is called saltation.

♤ Suspension-The holding-up of small particles like sand, silt and mud by the water as the stream flows is called suspension.

♤ Solution-Some parts of rock fragments are dissolved in the river water and are thus transported.