rivers]

Question 1

sedimentary rock

Answer 1

characterisitcs. small particles of rock
formation: weight of the materials compress the sediment
locations: form near the earths surface

Question 2

igneous intrusive

Answer 2

hard and contains large crystals
formed by magma cooling underground
fold mountains along destructive plate boundaries

Question 3

igneous volcanic

Answer 3

very hard and has smooth crystals
lava cooling on the earths surface
giants causeway ireland

Question 4

metamorphic

Answer 4

have been changed in shape or form
begin as igneous or sedimentary but are altered by heat and pressure
along destructive plate boundaries.

Question 5

uk spread of rocks

Answer 5

south and most of Ireland sedimentary

scotland northe ireland metamorphic and igneous

Question 6

how does mechanical weathering occur

Answer 6

caused by a temperature difference

when water gets into cracks and it freezes it expands

Question 7

chemical weathering

Answer 7

rainwater is slightly acidic

it can react with the minerals

Question 8

definition of mass movement

Answer 8

movement of rocks downstream sue to gravity helped by weaker rocks

Question 9

what is a confluence

Answer 9

the point at where a tributary meets the main river

Question 10

different courses of a river

Answer 10

upper course steep sides
midddle course flood plain begins sides still steep
lower course wide flat flood plain with very gentle sides

Question 11

changes across a river

Answer 11

depth increases
velocity increases
discharge increases
steepness of the river
decreases
channel roughness decreases

Question 12

how is a water fall formed

Answer 12

hard rock lies over soft rock
overhang from hte undercutting of the soft rock
plunge pool created bythe large fallen angular boulders falling down
steep sided gorges form as the waterfall retreats.

Question 13

meander formation

Answer 13

the flow of the water swings from side to side
directing the line of maximum velocity towards the ourside bend forming a river cliff
on hte inside of the ben there is a decrease in velocity and therefore this means that there is deposition forming agently sloping bank called a point bar
the water flows forming in a cork screw motion
overtime deposition occurs causing the river to bend further

Question 14

oxbow lake formation

Answer 14

horshpe shape of the meandr becomes tighter creating a swan neck shape this continues until ends become vey close together
river breaks thorugh at a time of high discharge
loop is cut off from main channel and will slowly fill up with sediment

Question 15

levee formation

Answer 15

during a flood thick and course sediment at comes to a channel edges
thin and fine sediment goes to the outer edges
natural levees are built up by many floods
increased friction and floodplain slows the river down

Question 16

ways to prevent flooding

Answer 16

changing the course of a river: is where ocurse of a river is changed, water is also slowed down uses natural processes and features, however if land use changes may have to be reverted.
planting trees afforestation. trees intercept the flow of water and slow down the transfer of water and slow down the transfer to river channels. water is soaked up by trees
less runoff not imediate impact
dams barrier can hold water and produce energy very expensive u tdoes produce enrgy