river test 1

Question 1

what is traction

Answer 1

Boulders roll along the river bed because there isn’t a enough energy

Question 2

what is surface run off

Answer 2

Water travels quickly on top of the soil back to the river

Question 3

Rain, hail sleet snow fog

Answer 3

precipitation

Question 4

Water helps to create a sliding plane so the soil moves downhill as a single slab

Answer 4

landslide

Question 5

The global hydrological cycle

Answer 5

s a closed system because it has no extrenal inputs

Question 6

The drainage basin hydrological

Answer 6

is an open system because it has external inputs.

Question 7

Dranagine basin

Answer 7

total area of land drainage by a river and its tributaries

Question 8

Floodplain

Answer 8

type of deposition the low lying wide floor

Question 9

what is vertical erosion powerpoint

Answer 9

• downwards erosion in upper course of a stream
• load consist of large boulders peoples and sand
• mostly rolled along stream bed
• potholing is common
• so stream bed eroded most

Question 10

what is lateral erosion powerpoint

Answer 10

• is sideways erosion in middle/lower course of a river
• river meanders and helicoidal flow common
• causes undercutting of river banks and slumping
• so sides of channel eroded more than bed

Question 11

what does the watershed mark

Answer 11

dividing line between neighbouring drainage basin

Question 12

how does channel density effect run off

Answer 12

high channel network density rapid run off

Question 13

how does land use effect run off

Answer 13

cleared and paved surfaces = rapid un off

Question 14

what is a hydrograph

Answer 14

a graph showing a rivers rate of discharge over time past a septic point

Question 15

how is a v shaped valley formed

Answer 15

river has been cut down by vertical erosion and mass movement of material down the valley sides

Question 16

how is interlocking spur formed

Answer 16

formed as river swings from side to side. the river cuts down between the spur rather than eroding them away

Question 17

what happens when a waterfall retreats upstream

Answer 17

gorge

Question 18

How are meanders formed

Answer 18

erosion and deposition

• lateral erison us more significant here because river is close to sea
• on the outside gf the bend ;lateral erosion forms a river cliff. on the inside of the bend the water flow is slower and deposition forms a slip off slope.

Question 19

how are oxbow lakes fromed

Answer 19

the neck of the land within menders narrow iover time on the outside bend. deposition will occur to cut off the orginal meander, leavubgf a oxbow lake

Question 20

chemical weathering

Answer 20

decomposition of rocks such as limestone dissolve slowly due to slightly acid rainfall

Question 21

biological weathering

Answer 21

Burrowing - tree roots grow down into the rock and exert a physical force pushing apart the rock. Exploits any weakness in the rock

Question 22

physical weathering

Answer 22

freeze thaw
Water enters cracks in the rock.
When temperatures drop, the water freezes and expands causing the crack to widen.
The ice melts and water makes its way deeper into the cracks.
The process repeats itself until the rock splits entirely.

Question 23

what is a source

Answer 23

a rivers origin

Question 24

what is confluence

Answer 24

where 2 rivers join

Question 25

what is the mouth

Answer 25

where river flows into the sea

Question 26

where does a waterfall occur on a drangainge basin

Answer 26

source and tributary

Question 27

where does a oxbow lake occur in drainage basin

Answer 27

confluence and tributary

Question 28

what is a tributary

Answer 28

a river or stream flowing into a larger river or lake

Question 29

how is a waterfall formed

Answer 29

Waterfalls occur where a band of hard rock overlies a softer rock (1). This softer rock is eroded more quickly than the harder rock (1) and, over time, this creates an overhang of hard rock (1). This overhang is unsupported so it collapses (1).