1.3 River Channel Processes and Landforms Flashcards
What is Hydraulic Action?
The sheer force of water hitting riverbanks and beds, compressing air into cracks, leading to erosion.
What is Solution?
The chemical dissolution of soluble rocks (e.g., limestone) by acidic river water.
What is Abrasion?
The process where the river’s load scrapes and grinds against the bed and banks, wearing them away.
What is Attrition?
Rocks hitting each other whilst moving downstream causing them to be smaller smoother and rounder
What is Traction?
Large boulders and rocks roll along the river bed during high energy conditions.
What is Saltation?
Small pebbles and stones bounce along the river bed.
What is Suspension?
Fine particles like silt and clay are carried within the river’s flow.
What is Solution?
Dissolved minerals are transported invisibly in the water.
What is the Hjulström Curve
A graph showing the relationship between river velocity and the size of particles that can be eroded, transported, or deposited.
What is Laminar Flow?
A smooth, parallel flow of water where layers do not mix (common in slow-moving rivers).
What is Turbulent Flow?
A chaotic, swirling flow of water caused by obstacles and varying channel shapes.
What is Helicoidal Flow?
A eddy-like movement of water, commonly found in meanders, moving material from outer to inner banks.
What is the Thalweg?
The fastest flowing part of the river, typically found in the deepest section of the channel.
What is a Braided Channel?
A river with multiple intervening channels, typically formed in areas with high sediment loads and variable discharge.
What is a Meandering Channel?
A river with pronounced bends and curves, often found in the middle and lower course.
