Topic Three (1.3): River Channel Processes and Landforms

Introduction

This topic examines river channel processes and the landforms that they create.

You will study:

Channel processes.
Erosion: abrasion/corrasion, solution, cavitation and hydraulic action.
Load transport: traction, saltation, suspension and solution.
Deposition and sedimentation: the Hjülstrom curve.
River flow: velocity and discharge, patterns of flow (laminar, turbulent and helicoidal) and thalweg.
Channel types: straight, braided and meandering.
Landforms: meander (river cliffs, point bars, oxbow lakes), riffle and pool sequences, waterfalls, gorges, bluffs, floodplains, levées and deltas.

Read and Make Notes

For this topic, you will need to work through pages 8 to 16 of your textbook, completing the Activities at the end of the Section.

Download and Print

Download and print out these resources to accompany your notes:

[From an exam paper]

Top Tips

Make sure that you understand the following key points:

The Hjulstrom curve comes in lots of iterations (versions) although they do primarily have the same information on them as it is a standardised model. Familiarise yourself with more than just the textbook version which uses colour in a way an exam paper never will! A simple search in a search engine will bring up a number of different formats beyond the two provided here – try to understand each one as the exam could use any one of the formats.
Link up landforms and processes in your notes and identify the order these occur from the source to the mouth of the river. The textbook delivers this information in the order of the specification which is not the sequence that they occur from source to mouth! Identify which can occur in the upper course, middle course and lower course and why this is the case.
Rapids and waterfalls occur in areas where sediment layers have been tilted or uplifted (by tectonic processes) and more resistant rock overlies less resistant rock with the less resistant rock becoming exposed. Rapids can therefore be a precursor to waterfalls as well as a landform in their own right.

Key Terms