Rivers

Question 0

What is a tributary?

Answer 0

A smaller river which joins a larger river

Question 1

What is a river basin?

Answer 1

An area of land drained by one main river

Question 2

What is a confluence?

Answer 2

The point where a tributary meets a river

Question 3

Name 4 features of the upper course

Answer 3

1) Interlocking Spurs
2) V-shaped valleys
3) Waterfalls
4) Gorges

Question 4

Name 3 features of the middle course

Answer 4

1) Meanders
2) Oxbow Lakes
3) Floodplains

Question 5

Name 3 features of the lower course

Answer 5

1) Delta
2) Mouth
3) Levees

Question 6

Name the 5 processes for precipitation to go into a river

Answer 6

Surface runoff
Infiltration 
Percolation
Through flow
Ground-water flow

Question 7

Describe infiltration

Answer 7

When water is absorbed into the soil

Question 8

Describe percolation

Answer 8

The downward movement of water through soil

Question 9

Describe through flow

Answer 9

The lateral movement of water through the soil

Question 10

Describe ground-water flow

Answer 10

The lateral movement when water hits layer of impermeable rock

Question 11

Describe surface runoff

Answer 11

When water travels along the surface of the ground due to saturation

Question 12

What are the inputs, outputs and stores in the water cycle?

Answer 12

Inputs - precipitation
Outputs - transpiration
Stores - trees, soil, lakes

Question 13

What are the 3 types of weathering and give an example of each

Answer 13

1) Biological - burrowing animals/roots
2) Chemical - acid rain
3) Physical - freeze thaw

Question 14

What are the 4 types of erosion?

Answer 14

1) Hydraulic Action - force of water
2) Abrasion - rocks beat on bed/banks
3) Attrition - rocks beat together
4) Corrosion - chemicals wear rock

Question 15

What are the 4 types of transportation in rivers?

Answer 15

1) traction - rolling
2) saltation - bouncing
3) suspension - suspended in water
4) solution - dissolved/chemical

Question 16

What increases deposition?

Answer 16

Shallow water, low gradient on banks, too much sediment, and human activity

Question 17

How are V-shaped valleys formed?

Answer 17

Lateral and vertical erosion works on the banks and bed.
Valley sides become saturated and slump.
Precipitation and weathering erode banks.

Question 18

How are interlocking spurs formed?

Answer 18

When a river meets areas of hard rock it erodes around it, forming hills either side.

Question 19

How are waterfalls and gorges formed?

Answer 19

As the river reaches softer rock or the rivers gradient slows down so it cuts downwards. The water forms a plunge pool at the bottom which erodes the softer rock underneath until the hard rock on top forms an overhang and falls. This way the river moves upstream leaving a gorge

Question 20

How are meanders formed?

Answer 20

On the outside of a meander, the current is faster and can carry more material eroding the banks forming river cliffs.
On the inside, the current is slower and material is deposited forming a slip-off slope.
Causing the bend to increase

Question 21

How are ox-bow lakes formed?

Answer 21

Continued erosion on the neck of the meander will cause the river to break through. Deposition will block off the old meander leaving an oxbow lake

Question 22

How are deltas formed?

Answer 22

At the point where the river meets the sea, if the rate of deposition is greater than the rate of sediment removal by the sea; a delta is formed

Question 23

What physical factors cause flooding

Answer 23

• Heavy rainfall
• Saturated ground
• High silt levels/undredged
• Land shape
• Impermeable rock
• Snow melt

Question 24

What human factors cause flooding?

Answer 24

• Building on floodplains
• Dams
• Obstacles (bridges)
• Deforestation
• Canalisation