Physical Uk - Rivers

Question 1

Features and processes in the upper course

Answer 1

• vertical erosion
• waterfalls
• narrowest part of the river
• slowest flow

Question 2

Features and processes in the middle course

Answer 2

• lateral erosion
• meanders
• ox bow lakes
• river beach
• deeper water

Question 3

Features and processes in the lower course

Answer 3

• lateral erosion
• deltas
• floodplains
• deepest water
• fastest flow

Question 4

Explain how two channel characteristics change along a river’s long profile

Answer 4

1) as river flows from downstream discharge increases due to more water added by tributaries
2) as river flows downstream particle size decreases because as they are transported from upper to lower course more erosion occurs reducing particle size

Question 5

4 transportation processes

Answer 5

• traction
• saltation
• suspension
• solution

Question 6

Traction?

Answer 6

Large stones dragged along

Question 7

Saltation

Answer 7

Small pebbles picked up and dropped

Question 8

Suspension

Answer 8

tiny particles of sediment carried in the rivers current

Question 9

Solution (transportation)

Answer 9

Dissolved chemicals carried in solution

Question 10

4 erosional processes

Answer 10

• abrasion
• attrition
• hydraulic action
• solution

Question 11

Abrasion

Answer 11

Sand and pebbles dragged along river bed

Question 12

Attrition

Answer 12

Rocks and stones knock together

Question 13

Hydraulic action

Answer 13

Fast flowing water forced into cracks breaking up banks

Question 14

Solution (erosion)

Answer 14

alkaline rocks dissolved by acid rain

Question 15

Thaweg?

Answer 15

Fastest flow of the river

Question 16

Helicoidal flow

Answer 16

a flow of water moving material from the outside of one meander bend and depositing it in the inside of the next bend

Question 17

Levee?

Answer 17

Raised area of land on the banks of the river

Question 18

3 types of delta

Answer 18

• Niger delta - fan shaped
• Mississippi delta - birdsfoot
• Ebro delta - cuspate

Question 19

Transpiration?

Answer 19

Water lost through pores in vegetation

Question 20

Percolation

Answer 20

Water seeping deeper below the surface

Question 21

infiltration

Answer 21

Water sinking into the soil/rock from the ground surface

Question 22

Throughflow

Answer 22

Water flowing through soil layer parallel to the surface

Question 23

Groundflow

Answer 23

Water flowing through rock layer parallel to surface

Question 24

What are the 3 factors that cause hydrographs to differ?

Answer 24

1) antecedent rainfall - amount of water already in the ground before
2) geology - sandstone/chalk are permeable and absorb water but clay is permeable so surface run off occurs
3) vegetation - rain taken up by plants then evaporates/transpires so never reaches the ground

Question 25

8 causes of flooding

Answer 25

1) heavy rain 2) snow melt 3) antecedent rainfall 4) hot dry weather 5) deforestation 6) impermeable rock 7) steep slopes 8) urbanisation

Question 26

What are 4 river flood defences

Answer 26

- flood wall - dredging - construct levees - afforestation

Question 27

What is a negative of flood defences

Answer 27

they disperse water quickly and increase flood risk downstream

Question 28

What is a negative of dredging

Answer 28

Speeding up water flow increases flood risk downstream

Question 29

What is a negative of constructing levees

Answer 29

Water can rise over the levee

Question 30

What is a negative of afforestation

Answer 30

Trees take a long time to grow