geography - rivers

• hydraulic action is when water crashes into gaps in the soil and rock, compressing the air and forcing particles apart
• abrasion is when the flowing of water picks up rocks from the bed that smash against the river banks
• corrosion is when minerals such as calcium carbonate (the main part of chalk and limestone rocks) are dissolved in the river banks
• attrition is when rocks carried by the river smash against one another, so they wear down into smaller and more rounded particles
• solution is when soluble minerals such as calcium carbonate any type of flow minerals are dissolved from the soil or rocks and carried along the flow
• suspension is when small particles e.g clay and silt occurs in all but the slowest flowing rivers. tiny particles are carried along the distances in the flowing river
• saltation is when sand and small gravels, more energetic rivers with higher velocities the sediment bounces and skips along
• traction is when larger gravels, cobbles and boulders only common in high energy river channels or during flood events. the bed load rolls along in contact with the river bed