Landforms

Question 1

what river landforms are caused by erosion?

Answer 1

-waterfalls and gorges
-interlocking spurs

Question 2

where are waterfalls and gorges found?

Answer 2

in the upper course

Question 3

how are waterfalls and gorges formed?

Answer 3

•softer rock is eroded by hydraulic action and abrasion more than the layer of harder rock over it
•the water erodes the softer rock further undercutting the hard rock and creating a waterfall
•over time the hard rock becomes unsupported and collapses due to erosion. The collapsed rock swirls around the foot of the water fall eroding softer rock by abrasion creating a plunge pool
•Overtime, the waterfall retreats leaving behind a gorge

Question 4

What are interlocking spurs?

Answer 4

A series of ridges projecting out on alternate sides of a valley and around which a river winds its course.

Question 5

how are interlocking spurs formed?

Answer 5

•vertical erosion occurs in the upper course creating a v shaped valley
•the river isn’t powerful enough to erode laterally so it winds around hills made of resistant rock
•this creates an interlocking spur

Question 6

where are interlocking spurs found?

Answer 6

in the upper course of a river where rocks are hard

Question 7

what are rapids?

Answer 7

fast flowing sections of river where the gradient is quite steep and water is turbulent

Question 8

how are rapids formed?

Answer 8

they are formed from ridges of harder rock amongst soft rock

Question 9

where are rapids found?

Answer 9

the upper course

Question 10

What river landforms are caused by deposition and erosion?

Answer 10

meanders and oxbow lakes

Question 11

where are meanders and oxbow lakes found?

Answer 11

the middle course

Question 12

how are meanders formed?

Answer 12

•fast flowing water in the outside bends wear the river away and overtime undercuts the bank
•the river deposits its load of mud and shingle on the inside bend where the river flows slowly
•the outside bend continues to cut into the bank resulting in the river bending more

Question 13

What does the cross section of a meander look like?

Answer 13

Question 14

how are oxbow lakes formed?

Answer 14

•the fast flow of water on the outside bend results in erosion
•the outside bends move closer together and the meander neck becomes more narrow
•when there is a high discharge the river cuts across the neck and takes a straight course leaving an oxbow lake

Question 15

What landforms are caused by deposition?

Answer 15

-floodplains
-levees
-estuaries

Question 16

what are levees?

Answer 16

raised embankments at the side of the river channel that occur when a river is prone to flooding

Question 17

how are levees formed?

Answer 17

•when a river bursts at it’s banks friction with land reduces energy causing deposition of heavy sediment close to the river. The sediment becomes progressively smaller further from he channel
•after every flood the banks are built up higher on the side of the river forming levees

Question 18

where are levees found?

Answer 18

lower course

Question 19

what are floodplains?

Answer 19

a large area of flat land either side of a river that is prone to flooding

Question 20

where are floodplains found?

Answer 20

middle and lower course

Question 21

how are floodplains formed?

Answer 21

•they are formed meanders migrate across due to lateral erosion
•when they reach the edge of the floodplain they erode the valley side creating a buff

Question 22

what are estuaries?

Answer 22

a tidal part if the river where fresh water migrates with salt water from sea

Question 23

how are estuaries formed?

Answer 23

•they are formed as the tide reached its highest point where water moves slow and sediment is deposited
•overtime more and more builds up creating large areas of mudflats snd muddy banks are exposed

Question 24

where are estuaries found?

Answer 24

at the mouth of the river on the lower course

Question 25

What landfrorms can be found along the river tees

Answer 25

-High Force is a waterfall found in Forest-in-Teesdale
-There are meanders in Darlington where the lower course of the river is