definitions of types of erosions , transportation and landforms

Question 1

hydraulic action

Answer 1

its when the sheer power of water smashes against the river banks and causes air particle to be trapped in the cracks of the rocks. This causes pressure in the cracks causing rocks to break down and erode

Question 2

abrasion

Answer 2

the pebbles being transported wear away the bed and banks of the river channel.

Question 3

atrittion

Answer 3

when the materials being carried by the the river hits each other and the pieces become rounder and smaller

Question 4

solution

Answer 4

when rocks are dissolved by the slightly acidic water.

Question 5

traction

Answer 5

when larger rocks and material roll along the river bed.

Question 6

saltation

Answer 6

when smaller materials that can be lifted by the water bouces along the river bed

Question 7

suspension

Answer 7

lighter material carried by the river flow,

Question 8

solution

Answer 8

when materials are dissolved in the river water.

Question 9

waterfall

Answer 9

Waterfalls occur where there is a step in the landscape often where hard rock overlays soft rock (1)
The soft rock erodes due to hydraulic action, at a faster rate than the hard rock (1) leading to undercutting and the formation of a plunge pool (1)
This leaves an overhang of hard rock which eventually collapses due to gravity (1)

Question 10

gorge

Answer 10

gorges occur where there is a step in the landscape often where hard rock such as dolerite overlays soft rock such as limestone (1)
The soft rock erodes due to hydraulic action, at a faster rate than the hard rock (1) leading to undercutting and the formation of a plunge pool (1)
This leaves an overhang of hard rock which eventually collapses due to gravity (1)
The process is then repeated causing the waterfall to retreat upstream leaving a steep side gorge (1)

Question 11

v-shaped valleys

Answer 11

Vertical erosion is dominant in the upper course of the river
This cuts down into the river bed and deepens the river channel
Weathering and mass movement leads to material from the valley sides collapsing into the river forming a steep v-shaped valley

Question 12

interlocking spurs

Answer 12

In the upper course of the river the channel starts to meander
Erosion happens on the outside of the bend
In the upland areas this forms interlocking spurs

Question 13

meanders

Answer 13

1In lowland areas lateral erosion is dominant
2The fastest water flow is on the outside of the river bends, leading to erosion
3The slowest flow is on the inside of the river bends, leading to deposition:
The deposits form a slip-off slope
4Deposition on one side and erosion on the other leads to the meander migrating across the valley

Question 14

oxbow lakes

Answer 14

With distance downstream the size of the meanders increase
The erosion on outside bends can eventually lead to the formation of a meander neck
At a time of flood, the river may cut through the neck of the meander forming a straighter course for the water
The flow of water at entry and exit from the meander will be slower, leading to deposition
The meander becomes cut off from the main river channel, forming an oxbow lake