UK Physical Landscapes - Rivers

Question 1

What is source in terms of geography?

Answer 1

Where the river begins

Question 2

What is the mouth in geography?

Answer 2

Where the river meets the sea.

Question 3

What is the watershed in geography?

Answer 3

The boundary between two drainage basins.

Question 4

What is the main river channel in geography?

Answer 4

The main body of water carried by the river.

Question 5

What is a confluence in gography?

Answer 5

The point where two rivers meet.

Question 6

What is a tributary in geography?

Answer 6

A smaller river that flows into a larger river or a lake.

Question 7

What are the characteristics of a Upper valley on the long cross profile of a river?

Answer 7

1.Vertical erosion with hydraulic action, abrasion and attrition process.
2. Traction and salination at high flow.

Question 8

What are the characteristics of the middle part of the river on the long cross profile of a river?

Answer 8

1. Channel is deeper and wider.
2. Vertical erosion decreases, in importance more lateral erosion and deposition.
3. Suspension is the main type of transportation.
4. Load becomes smaller and angular.

Question 9

What are the characteristics of the end part of the river on the long cross profile of a river?

Answer 9

1. Channel is at it’s widest and deepest and may be tidal.
2. Deposition more important than erosion.
3. Large amount of load.

Question 10

What are the 4 processes of transportation?

Answer 10

1. Solution
2. Traction
3. Saltation
4. Suspension

Question 11

What is solution?

Answer 11

The transport of dissolved chemicals. This varies along the river depending on the presence of soluble rocks.

Question 12

What is traction?

Answer 12

Pebbles are rolled along the river bed. This is most common near the source of the river.

Question 13

What is saltation?

Answer 13

Pebbles bounced along the river bed.

Question 14

What is suspension?

Answer 14

Lighter sediment is suspended within the water, most commonly near the mouth.

Question 15

What are the processes of erosion?

Answer 15

1.Abrasion
2. Hydraulic power
3. Solution
4. Attrition

Question 16

What is abrasion?

Answer 16

When pebbles grind along the river bank bed in a sand papering affect

Question 17

What is hydraulic power?

Answer 17

The sheer power of the water as it smashes against the river banks. Air becomes trapped in the cracks of the river banks which causes the rock to break.

Question 18

What is solution?

Answer 18

When the water dissolves certain types of rocks.

Question 19

What is attrition?

Answer 19

Where rocks carried by the sea hit and knock against each other breaking them into smoother and smaller pieces.

Question 20

How do meanders and ox bow lakes work?

Answer 20

1. Water flows faster around the outside of a river.
2. Where the river bank is being eroded a steep river cliff is created. The deposited sand and mud creates a river beach or slip-off slope.
3. River continues to erode and deposit material. Curves become close. Erosion on the outside bends and deposition on the inside bends overtime.
4. The river breaks through this thin barrier. Water no longer flows around the meander but straight along the new channel.
5. The old course of the river channel becomes an oxbow lake. This lake soon dries out.

Question 21

How does a meander from?

Answer 21

1. On the outside of the bend, the river flows faster and causes erosion (mainly hydraulic action and abrasion) forming a river cliff
2. On the inside water flows slower so deposition happens creating a slip off slope.
3. Over time the bends become more exaggerated as this continues.

Question 22

How are floodplains formed?

Answer 22

During floods the river spreads out and deposits sediment. Overtime this builds a flat flood plain on either side of the river.

Question 23

How are levees formed?

Answer 23

When a river floods heavier materials deposited near the river channel. After many floods these deposits build up to form levees.

Question 24

What are some physical causes of floods?

Answer 24

1. Heavy rainfall
2. Saturated ground
3. Long rainfall
4. Snow melting

Question 25

What are some human causes for floods?

Answer 25

1. River blocked 2. Impermeable concrete 3. Drains 4. Built on flood plains.

Question 26

What is hard engineering?

Answer 26

The use of artificial structures, like seawalls or dams to control or modify natural processes.

Question 27

What is flood relief channels in hard engineering?

Answer 27

Diverts water from the main river into a separate channel. Advantages: Reduces flood risk, protect homes and businesses. Disadvantages: High construction and maintenance costs.

Question 28

What are embankments in hard engineering?

Answer 28

Raises the height of river banks increasing the rivers water holding capacity. Advantages: Increased river holding capacity Disadvantages: Very expensive to do

Question 29

What is soft engineering?

Answer 29

Using natural processes and the environment itself to reduce erosion and flooding.

Question 30

What is flood plain zoning in soft engineering?

Answer 30

Flood plain zoning controls what types of land use are allowed on a flood plain. Advantages: reduces risk to protect properties and people Disadvantages: Doesn't help areas that are already built upon.

Question 31

What is afforestation in soft engineering?

Answer 31

Planting trees to intercept rain water. Advantages: reduces flood risk, supports wildlife Disadvantages: takes a long time and a large area of land needed.