Chapter 9: Rivers

Question 1

Source

Answer 1

The beginning or start of a river

Question 2

Cource

Answer 2

The route a river takes to the sea

Question 3

Confluence

Answer 3

The point at which two rivers or streams join together

Question 4

Tributary

Answer 4

A stream or smaller river that flows into a large stream or river

Question 5

Mouth

Answer 5

The point where a river comes to an end, usually when entering the sea

Question 6

Drainage basin

Answer 6

The area of land drained by a river

Question 7

Watersbed

Answer 7

The area of high ground which seperates two drainage basins

Question 8

Estuary

Answer 8

The part of a river mouth that is tidal

Question 9

Stages of a river

Answer 9

Youthful stage (upper)
Mature stage (middle)
Old stage (lower)

Question 10

Procss of river erosion

Answer 10

Hydraulic action
Abrasion
Attrition
Solution

Question 11

Hydraulic action

Answer 11

The physical force of the moving water wears away and breaks off the rock and soil from the banks and bed of the river.

Question 12

Abrasion

Answer 12

Small stones carried by the river wear away the banks and bed of the river

Question 13

Abrasion

Answer 13

Small stones carried by the river wear away the banks and bed of the river

Question 14

Attrition

Answer 14

The small stones in the river are worn down and broken up as they hit off each other

Question 15

Solution

Answer 15

Rocks, such as limestone, and soil are dissolved by acids in the water

Question 16

The process of a river

Answer 16

1. The motion of water hitting against the surface
2. Scraping or wearing away
3. The impact of the rock grains hitting off one another
4. Minerals are dissolved in the water and carried along

Question 17

Processes of River transportation

Answer 17

Rolling
Bouncing
Suspension
Solution

Question 18

Rolling

Answer 18

The larger stones are rolled along the bed of the river. This process is known as traction

Question 19

Bouncing

Answer 19

The smaller pebbles are bounced along the bed of the river. This process is known as saltation

Question 20

Suspension

Answer 20

Light materials float along in water

Question 21

Solution

Answer 21

Materials dissolve and are carried along

Question 22

Youthful stage (upper)

Answer 22

Steep

Fast flowing

Low volume of water

Erosion

V shaped valledy, narrow, shallow channel

Interlocking spurs, waterfalls

Question 23

Mature stage (middle)

Answer 23

Gentle sloping

River stars to slow down

Higher volume of water

Erosion and deposition

Open, gently sloping, wider, deeper channel.

Meanders, oxbow lakes

Question 24

Old stage (lower)

Answer 24

Levelling off

Slow moving

Largest volume of water

Deposition

Flat and wide flood plain.

Flood plains, levees

Question 25

Process of river deposition

Answer 25

Reduction in the rivers speed
Increase in load size
Reduction in the rivers volume
When the gradient levels off

Question 26

Formation of a V shaped valley

Answer 26

The force of moving water in the river cuts downwards into the river bed, making it deeper. This process is called hydraulic action. It creates a deep, narrow valley.

Mechanical weathering and massmovement also weather the sides of the valley, breaking down rock and soil.

The material that falls into the river is carried downstream as part of the river’s load

Example: the upper course of the river Liffey, Lee and Moy

Question 27

Meanders

Answer 27

Curves or bends in the river in its mature stage. Meanders are formed by both deposition and erosion

Question 28

Owbow lakes

Answer 28

An oxbow lake is a horseshoe-shaped lake that is formed when a meander is cut off from the river

Question 29

Flood plains

Answer 29

A flood plain is a wide, flat area of land on either side of the river in its old stage. The river is now nearing the sea, and deposition had become the main process.

Question 30

Levees

Answer 30

A levee is a build up of alluvium on the banks of a river. Levees are caused by floods

Question 31

Deltas

Answer 31

Deltas are landforms of deposition found in the old stage of a river. A delta is a triangular or fan shaped area of land at the mouth of the river where it enters a lake or the sea.

Question 32

Interlocking spurs

Answer 32

Interlocking spurs are areas of high ground that jut out at both sides of the V-shaped valley.

Question 33

Waterfalls

Answer 33

A waterfall is a vertical drop in the cours of the river in its youthful stage.

Question 34

Patterns of drainage

Answer 34

Dendritic
Trellis
Radial
Deranged

Question 35

Dendritic

Answer 35

In a dendritic system, many triburary streams combine before joining the main river.

Question 36

Trellis

Answer 36

As a river flows along, smaller tributaries feed into it from the steep slopes on the sides of mountains. These tributaries enter the main river at an angle close to 90 degress, creating a drainage system that lookw like a trellis

Question 37

Radial

Answer 37

The stream radiates outwards from a central high point. This resembles the spokes on a bicycle wheel

Question 38

Deranged

Answer 38

There is no clear pattern to the rivers.