Transport
This is the river Calder looking downstream (to the viaduct) from original photo, the day after Boxing Day when this flooding occurred because of the burst bank. All sorts of debris was carried down that day.
The four different river transport processes
The four different river transport processes
These different processes are related with the size of the particles involved..Starting with smallest..
- Solution - minerals are dissolved in the water and carried along in solution.
- We saw this as part of the previous section's erosion. Particles 'in solution' (as in your chemistry lesson) can not be seen
- Suspension - fine light material is carried along in the water.
- These are light particles that are easily carried - whether wind or water
- Saltation - small pebbles and stones are bounced along the river bed.
- Traction - large boulders and rocks are rolled along the river bed - they creep.
- Levels of energy change as the river moves from source to mouth.
- With high levels of energy, large rocks and boulders can be transported. Energy levels near a river's source, when its course is steep and its valley narrow, are high.
- With low energy levels are low, only small particles can be transported (if any). When a river enters a lake or sea (at the mouth), it slows down so particles fall as silt..
- Deposition
- Deposition at the mouth of a river can form deltas - for example, the Mississippi Delta. Also when a river enters an area of shallow water or when the volume of water decreases - for example, after a flood or during times of drought.
- The flows of these substances follow the laws of physics about the relative sizes of the particles, the energy in the system, to determine thier velocity.
