Paper 1: River Landforms

Question 1

waterfall

Answer 1

water falls down a vertical drop in the river channel

Question 2

where do waterfalls form

Answer 2

rock upstream is capped by hard rock
-beneath is soft rock = erodes faster
-creates drop

Question 3

Beginning of waterfall formation

Answer 3

-water falls = erodes soft rock
-creates deep plunge pool at the base

Question 4

undercutting in waterfall

Answer 4

-continuous undercutting of soft rock
-overhang of hard rock
-lacks support underneath
-falls into plunge poo

Question 5

undercutting in waterfall

Answer 5

-continuous undercutting of soft rock
-overhang of hard rock
-lacks support underneath
-falls into plunge pool

Question 6

plunge pool erosion

Answer 6

eroded by hard rock that has collapsed
-through abrasion
-wider and deeper

Question 7

why does the waterfall retreat

Answer 7

-erosion + undercutting
-as it retreats it leaves a gorge

Question 8

gorge formation

Answer 8

-waterfall retreats
-leaves steep sided valley downstream

Question 9

meander

Answer 9

large bend in a river
-mainly found in middle course

Question 10

floodplain

Answer 10

flat area of land forming valley floor
-either side of river channel
-in lower/middle course

Question 11

levee

Answer 11

-a raised river bank made of sediment

Question 12

slip off slope

Answer 12

-curved beach-like feature inside river bend
-gentle
-sediment deposited due to friction = loss of energy

Question 13

river cliff

Answer 13

-steep drop into river on outside bend
-made of bare earth
-lots of erosion = less friction

Question 14

Meander formation

Answer 14

-faster current swings to one side
-cuts into banks - erosion
-forms a river cliff
-opposite side slow current
-deposits load = slip off slope
-meander is narrower

Question 15

Ox bow formation beginning

Answer 15

-riffles form = area of faster/slower currents
-current flows corkscrew-like (helical)
-erosion on outer bends = neck of meander narrows

Question 16

Meander neck narrows =

Answer 16

-river cuts through
-takes straighter path
-straight channel forms

Question 17

Final stage of ox bow lake formation

Answer 17

-deposition on either side of river channel
-cuts off meander
-leaves an ox bow lake + new straight channel

Question 18

Features of river estuaries

Answer 18

-many km wide
-mudflats that are visible at low tide
-salt marshes + salt resistant plants
-low lying relief
-lower course

Question 19

estuary

Answer 19

part of river that meets lake/sea
-transition zone
-river widens

Question 20

Flood plain formation

Answer 20

-river bursts its banks
-finest sediment is carried furthest
-creates flat low lying land
-very fertile = agricultural use

Question 21

Levee formation

Answer 21

-when the river floods
-heaviest sediment is deposited first at channel edges
-builds up
-protects risk of future floods

Question 22

Estuaries formation

Answer 22

-river current flows towards sea
-tide flows towards river
-they meet = velocity declines
-deposition of load

Question 23

mudflats

Answer 23

deposited sand and silt builds up
-covered at high tide
-exposed at low tide
-could grow vegetation

Question 24

high tide

Answer 24

-sea moves furthest to coast