quiz 15 Flashcards
What is lateral erosion?
Where the river erodes sideways
What are the 3 main fluvial processes?
Erosion, transportation and deposition
What occurs in abrasion?
Rocks being moved by the river rub against the riverbed, wearing down the rock and riverbed
What occurs in hydraulic action?
The physical power of the water colliding with rocks breaks them up
Describe how the long profile of a river valley changes as it moves downstream
Steep in the upper course, the gradient decreases in the lower course
What occurs in attrition?
Rocks being moved by the river collide with each other and wear away, becoming smaller and round. Rocks in the lower course are therefore smaller than in the upper course
What occurs in traction?
Large particles roll along the river bed
What are the 4 main types of transportation in rivers?
Traction
Saltation
Suspension
Solution
What occurs in solution?
Rock dissolves into the water of the river
Where is deposition likely to occur?
Where rivers are shallow
Where rivers reach their mouth
Where the volume of water decreases
What are the 3 courses of a river?
Upper,middle and lower
In what type of erosion does the river valley become deeper?
Vertical erosion
Describe how the cross profile of a river valley changes as it moves downstream
The river valley becomes wider and less steep as you go downstream and the river channel becomes wider
What occurs in suspension?
Small particles are carried along in the water above the river bed
Why do rivers deposit the materials they are transporting?
They slow down and lose energy
