Rivers

Question 1

Source of a River

Answer 1

The beginning of a river

Question 2

Confluence

Answer 2

Where two rivers meet

Question 3

Drainage Basin

Answer 3

Is where all flowing surface water converges to a single point, such as river mouth

Question 4

Watershed

Answer 4

Is an area if highland between two drainage basins

Question 5

Mouth

Answer 5

Is where a river flow into a lake or the sea

Question 6

Tributary

Answer 6

A small river or stream that flows into a large river

Question 7

Hydraulic action

Answer 7

The weight of the water smashing into the bed and banks of the river channel

Question 8

Attrition

Answer 8

Stones colliding with each other in the channel, this wears them away

Question 9

Abrasion

Answer 9

Stones colliding with the bed and banks damaging them

Question 10

Solution

Answer 10

Chemicals in the water dissolving the bed, banks and bedload

Question 11

Traction

Answer 11

Stones rolling along with the river bed

Question 12

Suspension

Answer 12

Method of transporting very small, fine sediment in a river. The sediment is probably eroded from very large rocks upstream.

Question 13

What are the small, fine sediments eroded from lager rocks called

Answer 13

Silt

Question 14

Solution

Answer 14

Is where water dissolves certain types of rock. ( Chalk and limestone cliff are prone to this type of erosion in the UK.)

Question 15

Saltation

Answer 15

Stones bouncing along the river bed

Question 16

How are interlocking spurs formed?

Answer 16

Interlocking spurs form when there are areas of hard rock, which are harder to erode, so the river bends around it.

Question 17

The hard rock on the top ( CAP ROCK ). Soft rock is the rock underneath and gets worn away by?

Answer 17

Hydraulic action and abrasion

Question 18

The undercutting happens until the Cap rock

Answer 18

Collapses

Question 19

The waterfall steps backwards each time and leaves behind a

Answer 19

Gorge

Question 20

Meanders are

Answer 20

Simple bends in the rivers

Question 21

Where do meanders occur

Answer 21

They occur in middle and lower courses of the river where Lateral erosion is common

Question 22

What is Lateral erosion

Answer 22

Lateral erosion is sideways erosion by a river on the outside of meander channel.

Question 23

How are meanders made

Answer 23

Meanders are made when the inside of the same bend, the water is travelling far slower meaning It cannot carry its bedload so it’s forced to deposit it. The new sand and gravel which had just been deposited makes the river slow down even more, leading to more deposition. Deposition makes the river narrower on the inside meaning that the river is migrating sideways.

Question 24

How is an Ox-bow lake made?

Answer 24

Erosion happens on the outside of the bends, which brings the two meanders together. Over time the two meanders get closer and closer making the neck narrower as they get closer and closer. During a flood event the river will cut through the final neck and straighten the river, leaving behind an Ox-bow lake. Overtime the lake will dry up as no more water is added to it.

Question 25

What are leeves

Answer 25

Leeves are naturally forming banks, found on either side of the river bank in the lower course.

Question 26

What are floodplains

Answer 26

Floodplains are naturally occuring areas of flatland which make up the bottom of the valley in the lower course of the river.

Question 27

Estuaries

Answer 27

Estuaries are found at the mouth of a river. It is where fresh and salty water mix. The mixing causes the water to slow down and causes the mud to drop out of suspension. This is why we find mud flats at the river mouth.

Question 28

What is river discharge?

Answer 28

RIver discharge is the volume of water that flows down a river per second. It is measure in ( Cubic meters per second ) CUMECS

Question 29

Where are river discharge measured?

Answer 29

They are measured at places called Gauging stations.

Question 30

What is the Hydrograph?

Answer 30

The Hydrograph is the measure of distance at a certain point in the river.

Question 31

Why does lag time happen?

Answer 31

lag time happens because most rain water doesn’t land directly on the river, there’s a delay as rain water gets into the channel.

Question 32

How does the rain water get into the river?

Answer 32

It gets there by flowing quickly overland this method is called Surface Runoff or by soaking into the ground, its called infiltration.

Question 33

CUMEC ( cubic metre per second is the same as )

Answer 33

Tonne bag

Question 34

What is hard engineering?

Answer 34

Hard engineering is the use of man made structures to control the rivers and to stop flood events from happening.