Landscapes of the UK
Physical Landscapes
Upland
Lowland
Glaciated
Distinctive characteristics
Geology
Human Activity
Climate
Mostly found in similar areas to Upland areas, NW Scotland, Wales and the Lake District
Mostly found in the north and west of the UK, NW Scotland, The Pennies, Lake District and cover most of Wales
Mostly found in the south and east of England, The London Basin, the Fens in East Anglia.
Flatter Land, Crop Farming, Better Soil's, Warmer Temperature, More Vegetation
Steep Slopes, High Land (V-Shaped Valleys), Thin Soils, Colder Temperature, Sheep Farming, Less Vegetation.
Fancy term that means rock type.
Igneous Rocks - Very hard (Granite and Basalt). Very old rocks, they are impermeable so often will have rivers on their landscapes. As they are hard they erode and weather very slowly so lead to make up upland areas.
Sedimentary Rocks - much softer than igneous. (Chalk and limestone) They are permeable so will let water through them which means that there landscape is less likely to have rivers, they are soft so erode and weather more quickly that igneous rocks so lead to lowland areas.
Geomorphic Processes
Geomorphic Processes change the shape of the land. They include erosion, weathering, transportation, deposition and mass movement. They act over different timescales. Some happen very quickly whereas others can take thousands of years to change or create landforms.
Erosion
Erosion is the wearing away of materials by a moving force such as river or waves.
Hydraulic action - water is forced into cracks, which creates weaknesses in rocks, splitting them apart
Abrasion - sediment is thrown against a surface by water and causes the sediment to rub and wear away material (smooth)
Attrition - pebbles hit each other making the rocks break and get smaller and rounder.
Solution - rocks are dissolved in water by a chemical reaction.
Weathering
Weathering is material that has been broken down by the atmosphere, weathering takes a lot longer than erosion. Freeze-thaw weathering can take thousands of years
Mechanical weathering - the physical actions of rain frost and wind that create weaknesses in rocks.
Biological weathering - actions of living organisms such as plants and burrowing animals breaking down rocks.
Chemical weathering - minerals in the rocks reacting with chemicals, such as acid rain.
Transportation
Transportation is when a river carries material from one place to another.
A river transports in four ways:
Traction: Large boulders are rolled along the river bed or sea bed
Saltation - smaller particles are bounced along the river bed.
Suspension - very fine particles float
Solution - rocks dissolve and are carried by the river.
Mass movement
Mass movement is the movement of material down a slope due to the pull of gravity. There are tow different types: slumping and sliding
Sliding: Rock or lose material slide downhill, often due to heavy rain
Slumping: Collapse of weak rock, such as sand and clay. Again this is due to heavy rainfall.
Landforms that Rivers create
V-Shaped valley
Steep sided, narrow river valley that takes the form of a V shape.
It is formed by erosion as the river erodes vertically into the landscape.
Vertical erosion happens due to hydraulic action and abrasion. This leaves very steep valley sides that are then attacked by weathering processes such as freeze thaw and biological weathering. This weakens the valley sides which may collapse or cause some material to move down slope due to mass movement processes such as sliding.
Waterfall and Gorge
A band of harder more resistant rock was laid down on less resistant rock
The soft rock (limestone) erodes first by hydraulic action and abrasion
Leaving an overhang of hard rock
Due to lack of support and the pull of gravity the overhang collapses
A plunge pool forms as the hard rock erodes the river red due to hydraulic action and abrasion
Over time the waterfall retreats and a steep sided gorge forms.
Meanders
very common features in the middle and lower course of rivers. It is a curve or bend in a river.
Formation
In a straight channel the water flows from side to side, this can erode the river banks.
undercutting on the river bank causes the overhang to collapse, which forms a steep river cliff due to erosion.
on the inside bend of the meander, deposition occurs where the water is slower
when the river slows down and loses energy, it deposits its load to form a slip off slope
Ox-bow lake
an ox-bow lake is created when a meander is cut off. They are common in the middle course of rivers.
Erosion (hydraulic action and abrasion) take place on the outside of a river bend
The neck of the meander becomes narrower as the erosion continues. This is sometimes called a 'swans neck' meander.
At times of high discharge, flooding, the river breaks through the neck of the meander and becomes straight.
the old meander is now separated from the main river channel and deposition of sediment will eventually fill it in.
Levees
Leeves are raised river banks that are commonly found in the lower course. They are formed during flooding.
Formation
As water overtops the river banks, the water slows down from being very fast and loses energy
This causes sediment to be dropped on the river bank
Larger sediment is dropped first, which catches/traps the smaller sediment.
When the river flood again, the levees get larger and larger as more sediment is dropped
Floodplain
Floodplain is the flat land either side of a rivers banks.
It is formed over many thousands of years after a river floods and deposits fine material in layers either side of it. After successive floods the height of the floodplain increases as further sediment is desposited.