Rivers - keywords

Question 1

What type of land forms take place on upper course of a river?

Answer 1

Erosion land forms (e.g. waterfall, gorges)

Question 2

What type of land forms take place on the middle course of a river?

Answer 2

Erosion and deposition land forms (e.g. meanders)

Question 3

What type of land forms take place on the lower course of a river?

Answer 3

Deposition land forms (e.g. levees, estuaries)

Question 4

Hydraulic action

Answer 4

Force of water hitting the bed and banks causes material to break off

Question 5

Abrasion

Answer 5

When the load carried by the river repeatedly hits the bed and banks which dislodges particles

Question 6

Attrition

Answer 6

Stones carried by the river knock against each other, creating smaller, rounder pebbles

Question 7

Solution (erosion)

Answer 7

When river flows over chalk/limestone, rock is slowly dissolved by acidic river water

Question 8

In what course is the river at its fastest?

Answer 8

Lower course - as the channel is wider and there is a greater volume of water, less friction occurs and this causes a fast flow

Question 9

Traction

Answer 9

Large boulders roll along the river bed

Question 10

Solution

Answer 10

Dissolved load is carried in the water

Question 11

Suspension

Answer 11

Small sediment is held in the river

Question 12

Saltation

Answer 12

Particles too heavy to be suspended bounce along the river bed

Question 13

Vertical erosion

Answer 13

Downward erosion of the river bed

Question 14

Lateral erosion

Answer 14

Erosion of the river banks rather than river bed

Question 15

Channel width

Answer 15

Distance from one bank to another

Question 16

Channel depth

Answer 16

Distance from surface of water to channel bed

Question 17

How does channel width and depth change downstream?

Answer 17

Width - increases as you move downstream

Depth - deeper as you move downstream

Question 18

Veocity

Answer 18

Speed of which water is moving through channel

Question 19

Is river fastest or slowest in lower course?

Answer 19

Fastest - there is a greater volume of water which reduces friction and increases velocity

Question 20

Discharge

Answer 20

Amount of water passing a given point in a given time

Question 21

What is discharge measured in?

Answer 21

Cumecs - cubic metres per second

Question 22

Hydrograph

Answer 22

A graph that plots river discharge after a storm

Question 23

Lag time

Answer 23

Time (in hours) between the highest rainfall and peak discharge
Shows how quickly water is transferred into a channel

Question 24

What type of hydrograph will impermeable rocks create?

Answer 24

Less water will be able to infiltrate, encourages more SRO

‘Flashy’ hydrograph with a short lag time and high peak discharge

Question 25

How will relief affect shape of hydrographs?

Answer 25

Steep = more SRF due to gravity -> high peak and short lag time 
Gentle = water can infiltrate + slows SRO into channel -> low flat hydrograph

Question 26

What shape of hydrograph will a small basin size create?

Answer 26

Short lag time and high peak - water has less time to infiltrate before reaching chanel

Question 27

What shape of hydrograph will a large basin size create?

Answer 27

Low, flat hydrograph - slow water transfer as water has more time to infiltrate through soil

Question 28

What shape of hydrographs will forests produce?

Answer 28

Low, flat hydrograph - forests intercept water and absorb it through their roots

Question 29

What shape of hydrographs will a strong rainfall create?

Answer 29

‘Flashy’ hydrograph - heavy rain can exceed infiltration/soil capacity which causes SRO

Question 30

What do we mean when we say ‘flashy’ hydrograph?

Answer 30

Hydrograph with short lag time and slow peak

Question 31

How will saturated soil result in a ‘flashy’ hydrograph?

Answer 31

This results in rapid overland flow/ SRO to river channel

Question 32

Where is River Tees located?

Answer 32

North East of England, high in the Pennine Hills near Cross Fell

Question 33

What is a hydrograph?

Answer 33

A graph to show the relationship between precipitation and how quickly a river responds to input of water

Question 34

How is a hydrograph useful for predicting floods?

Answer 34

You are able to identify which locations react more quickly to precipitation (urban areas) which makes them more likely to flood