uk physical landscapes

Question 1

what is weathering

Answer 1

process of rock being broken down by natural factors

Question 2

weathering examples

Answer 2

-physical weathering e.g. freeze thaw = when water in small cracks freeze and expand creating bigger cracks
-chemical weather e.g. oxidation of iron in carstone at hunstanton
-biological weathering e.g. plant roots pushing down into rocks

Question 3

what is erosion

Answer 3

when material is worn away

Question 4

4 states of erosion

Answer 4

-hydraulic action= sheer force of water
-abrasion= scraping action caused by transported sediments
-attrition= knocking together of transported sediments
-solution= minerals are dissolved in water

Question 5

how are headland & bays formed

Answer 5

1) headland is more resistant to erosion therefore it juts out to create it
2) bays are less resistant to erosion so it creates an indent

Question 6

how is cave, arch, stack and stump formed

Answer 6

1) weaknesses in joints & bedding planes create cracks
2) HA + A widen crack to form a cave
3) HA + A & weathering cause cave to collapse forming an arch
4) HA + A & weathering cause arch to collapse forming a stack
5) HA + A cause stack to reduce to a stump

Question 7

how is a cliff, wave cut notch platform formed

Answer 7

1) HA + A erode base off c;iff to create a wave cut notch
2) cliff now “hangs” as an overhang
3) as the base continues to erode, the overhang is no longer supported & collapses
4) process repeats. cliff retreats & material left forms a slip way known as a wave cut platform

Question 8

how are spits formed

Answer 8

1) longshore drift causes beach sediment to be transported
2) sediment is deposited in direction of LSD (begins formation)
3) a change in wind direction causes the spit to curve

Question 9

what is transportation

Answer 9

when material is moved from on place to another

Question 10

4 states of transportation

Answer 10

-saltation= material bounces
-traction= material rolls
-suspension= floating material
-solution= dissolved material

Question 11

what is deposition

Answer 11

when material is no longer transported and settles out. Happens when the waves lost energy and heaviest material is always deposited first

Question 12

how are waterfalls formed

Answer 12

1)water flows down the hard and soft rock
2)HA + A erode the soft rock causing it to collapse
3)the unsupported hard rock then collapses
4)the debris is swirled around at the bottom of the waterfall creating a plunge pool
5)process repeats and waterfall retreats leaving a steep sided gorge

Question 13

how are meanders formed

Answer 13

1)the current is fastest on the outside of the bend because the river channel is deeper (less friction to slow water down)
2)more erosion takes place on the outside bend forming river cliffs due to HA + A
3)the current is slower on the inside because the river channel is shallower ( more friction to slow water down)
4)eroded material is deposited on the inside forming slip-off slopes

Question 14

how are ox-bow lakes formed

Answer 14

1)HA + A cause outside bends to get closer until theres only a small bit of land left between the bends (the neck)
2)the river breaks through the land and the river flows along the shortest course
3)deposition eventually cuts off the meander forming an ox-bow lake

Question 15

flood management schemes (hard engineering)

Answer 15

-Lake reservoirs= release water for agriculture & homes
-dams= last long + hydroelectric energy
-embankments (raised land)= expensive to build & maintain

Question 16

flood management schemes (soft engineering)

Answer 16

-restoring meanders= slows river - farm land lost + cheap
-afforestation= more tees,more rainfall, slows water into river - more soil saturation= more biodiversity
-flood warning (mitigation)

Question 17

river management schemes (hard engineering)

Answer 17

-straightening channels= increase velocity to remove flood water
-artificial levees= heightens river so flood water is contained
-deepening OR widening rivers= increase capacity for a flood

Question 18

river management schemes (soft engineering)

Answer 18

-afforestation= more tees,more rainfall, slows water into river - more soil saturation= more biodiversity
-demountable flood barriers
-managed flooding= naturally let areas flood - protect settlements

Question 19

physical cause of flooding

Answer 19

-prolong and heavy rainfall= soil becomes over saturated causing surface runoff
-geology= impermeable rocks cause surface runoff to increase river discharge

Question 20

human cause of flooding

Answer 20

-land use= tarmac and concrete are impermeable - prevents infiltration & causes surface runoff

Question 21

how are waves formed

Answer 21

the wind blows over the surface of the sea and causes friction producing a swell in the water

Question 22

how are tides formed

Answer 22

the moon and earth exert a gravitational pull on each other. on earth the pull causes the ocean to bulge out on both sides closest and farthest to the moon

Question 23

why do waves break?

Answer 23

1) waves start out at sea
2) as waves approach shore, friction slows the base
3) causes orbit to become elliptical until top of waves break over

Question 24

wave size depends on:

Answer 24

-wind speed (faster speed=larger waves)
-fetch= how far the wind blows (longer fetch=longer waves)
-wind duration (longer duration= larger waves)
-depth of water (deeper water=larger waves)

Question 25

what are constructive waves

Answer 25

a swash that is stronger than the backwash therefore builds up the coast

Question 26

what are destructive waves

Answer 26

a backwash that is stronger than the swash therefore erodes the coast

Question 27

4 coastal erosions

Answer 27

-hydraulic action
-attrition
-corrosion= chemical reaction which wears rock
-corrasion= rocks act like sandpaper which away cliffs

Question 28

what is a managed retreat (coastal defence)

Answer 28

-managed retreat= when the sea is allowed to reach its natural position by removing existing coastal defences
-disadvantages= settlements & farmland destroyed (compensation paid), little evidence it works
-advantages= maintenance costs low, nature conservation

Question 29

other coastal defences (hard engineering)

Answer 29

-sea wall= prevents erosion / expensive
-gabions= cheap, easy to build / ugly, corrode
-groynes= wider beaches which slow waves / narrower beaches causing greater erosion and floods

Question 30

other coastal defences (soft engineering)

Answer 30

-beach nourishment= wider beaches to slow waves / expensive, repeated process
-dune regeneration= wave energy absorbed / protection limited to small area