River Geomorphic Processes Flashcards
Erosion
Wearing away of the river bed and banks.
Vertical erosion- Downwards
Lateral erosion- Sideways
Hydraulic Action
Force of the water hitting the river bed and banks. Air becomes trapped in the cracks and crevices, causing them to break apart
Abrasion
Smoothes the land, sediment is thrown against a surface by water and rubs the material to smooth the landform
Attrition
Rocks being caried by the river are hit against each other making them smaller and rounder
Solution
Slightly acidic river water flows over rocks like limestone and sandstone, dissolving them
Suspension
Happens with the lightest sediment, carried by the river and occurs in the lower course
Saltation
Large pebbles that are too heavy to flow with the river , so they bounce along the river bed
Traction
Large rocks that are too heavy to flow with they river, so roll along the river bank, usually happens in upper course
Mechanical Weathering
The physical actions of rain frost and wind that create weaknesses in rocks,
Deposition
When the river loses its velocity, its sediment is dropped. Happens in shallower areas
Chemical Weathering
Minerals can react chemically in different ways, which weakens them. For example, water can react with some rocks to break them down, and air can weaken minerals through a process called oxidation
Biological Weathering
Rocks and land can be broken down by the action of living organisms such as plants and animals, for example rabits burrowing into river banks
Mass Movement
When material moves downhill due to the pull of gravity
Sliding
Where a section of land falls down a slope and dislodges other material on its way down
Slumping
Where material at the bottom of a slope moves outwards
