8 River Action

Question 1

Source

Answer 1

Place where a river begins
High ground

Question 2

Tributary

Answer 2

Stren or river that joins a larger one

Question 3

Confluence

Answer 3

The junction wheree two rivers join

Question 4

Mouth

Answer 4

Place where a river enters sea or lake

Question 5

Estuary

Answer 5

found at mouth of river where rivers current and seas tide meet

Question 6

Drainage basin

Answer 6

Entire area of land drained by a river and its tributaries

Question 7

Watershed

Answer 7

Area of high ground that separates one basin from another

Question 8

Course

Answer 8

Distance river reacels from source to mouth

Question 9

Fluvial

Answer 9

refers to processes associated with rivers and streams and the deposits and landforks created bt them

Question 10

5 Typess of river drainage patterns

Answer 10

Dendritic
Trellis
Radial
Parallel
Deranged

Question 11

What does a dendritic pattern look like

Answer 11

Branches of a tree
Random
Upland areas

Question 12

What does a trellis drainage pattern look like

Answer 12

Ladder
Right angled confluences
Found where folding had occured

Question 13

What does a radial drainage pattern look likke

Answer 13

Spokes of a wheel
Rivers run off a mountin or conical hill
Radiate from peak outwards

Question 14

What does a parallel drainage pattern look like

Answer 14

rivers flow parallel
Run across valleys

Question 15

What does a deranged drainage pattern look like

Answer 15

Streams have no particular direction
Lowland areas subjected to glacial deposition

Question 16

What are the 4 Proccesses of river erosion

Answer 16

1.Hydraulic action
2.Abrasion/Corrasion
3.Attrition
4.Solution/Corrosion

Question 17

factors that affect rate of river erosion

Answer 17

1.Vol of water
(Rivers in flood erode faster as theyve
more energy)
2.Speed/Velocity
(Erode faster when flow faster)
(this is affected by gradient and water
perimeter)
3.Hardness of rock
(Softer rocks are eroded easier)

Question 18

What is hydraulic action

Answer 18

River bed +bank is eroded by force of moving water. Loose fragments swept away
Joints of rocks englarged

Question 19

What is abrasion/corrasion

Answer 19

Material picked up by moving river erodes bed and bank of river

Question 20

What is attrition

Answer 20

Rocks nd pebbles rub against eachother as theyre moved by river.
Makes them smoother and smaller

Question 21

Solution/Corrosion

Answer 21

Soluble rocks in river channel are dissolved by acids in water
E.g Limestone dissolved by carbonic acid

Question 22

4 Processes of river transportation

Answer 22

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

Question 23

What is solution (transportation)

Answer 23

Dissolved rocks are carried in a solution
(Requires least energy)

Question 24

What is suspension

Answer 24

light materials (sand,clay) r carried by moving water as a suspendded load.
common in times of flood when water is brown

Question 25

What is saltation

Answer 25

Small light rocks/penbles are bounced along riverbed

Question 26

What is traction

Answer 26

Heavy materials are rolled dragged along riverbbed (Requires most energy)

Question 27

When does a river depostit its load

Answer 27

1.Volume decreasss (dry season, floods recede, water taken for agri use,) 2.Speed decreases (enters a sea, increase in roughness)

Question 28

What is the wetted perimeter of a river

Answer 28

The area of the riverbed and bank that comes into contact with water PART THATS WET

Question 29

Another name for youthful stage of a river

Answer 29

Upper valley

Question 30

Characteristics of upper valley/youthful stage

Answer 30

Upland area few tributaries Small vol of water Steep gradient Quick flow Vertical erosion

Question 31

Landforms of youthful stage/upper valley

Answer 31

V shaped valley Interlocking spurs Waterfalls

Question 32

What are eddy currents

Answer 32

Swirling action of water usually occurs as water enters a hole

Question 33

Formation of V Shaped Valley

Answer 33

1.Vertical erosion. Water uses energy to erode downwards 2. Weathering. Rivers on high ground so valley is weathered by freeze thaw 3.Mass Movement. Loose material travels down into valley 4.V Shaped Valley. Steep Sided narrow valley is formed

Question 34

What is differential erosion

Answer 34

Less resistand rocks are worn down at a faster rate than more resistant rocks Eg. Chalk is worn down quicker than granite

Question 35

Interlocking spurs formation

Answer 35

Youthful stage River