Paper 1 : Freshwater Drainage Basin

Question 1

Drainage Basin

Answer 1

An area where water supplied by precipitation is transferred to the ocean or larger stream.
- Includes all areas drained by a river.
- Divided by watersheds

Question 2

Confluence

Answer 2

Where 2 rivers meet

Question 3

Tributary

Answer 3

Smaller rivers join the larger river

Question 4

Watershed

Answer 4

The area of highland forming the edge of a river basin.

Question 5

Source

Answer 5

Where the river begins

Question 6

Mouth

Answer 6

The the river ends / meets the sea

Question 7

Channel

Answer 7

Where the river flows -> the drainage basin is an open system = has inputs and outputs + storage transfers

Question 8

Precipitation

Answer 8

Any moisture that falls from the sky.

Question 9

Interception

Answer 9

When an object stops precipitation from reaching the ground.

Question 10

Evapotranspiration

Answer 10

Water evaporating from the vegetation

Question 11

Infiltration

Answer 11

When water travels from the surface into the ground.

Question 12

Overland flow

Answer 12

Surface runoff

Question 13

Evaporation

Answer 13

Surface stores + rivers turning into water vapour

Question 14

Surface storage

Answer 14

Any water held on the surface

Question 15

Throughflow

Answer 15

The movement of water through unsaturated ground

Question 16

Soil moisture

Answer 16

Water stored below surface in unsaturated ground

Question 17

Groundwater storage

Answer 17

Water stored in saturated ground

Question 18

Groundwater flow

Answer 18

Movement of water through saturated ground

Question 19

Perlocation

Answer 19

Water travels from unsaturated ground into saturated ground

Question 20

River discharge

Answer 20

Discharge is the river that flows into the sea

Question 21

Factors that influence local hydrology

Answer 21

Amount, intensity, variability, type (snow,rain), geographical distribution

Question 22

Factors that affect evaporation

Answer 22

Temp, humidity, wind speed, vegetation, colour of surface

Question 23

Aquifers

Answer 23

Rocks that contain high amounts of water + provide a source of water, water moves slowly through permeable rock.

Question 24

Field capacity

Answer 24

The amount of water held in the soil after excess drains away

Question 25

Phreatic zone

Answer 25

Permanently saturated zone

Question 26

Cryosphere

Answer 26

66% of freshwater in high latitude+altitude regions, when it melts it becomes part of the hydrological cycle

Question 27

River discharge

Answer 27

Is the volume of water passing a given point over a set time

Question 28

River discharge equation

Answer 28

Cross sectional area x mean velocity

Question 29

River velocity

Answer 29

The speed and direction of a river (m/sec) Measure in the centre of river. Affected by friction = travels fastest at the centre and slower at banks + bed.

Question 30

Factors affecting velocity

Answer 30

Channel shape - measured by hydraulic radius = cross sectional area / wetted perimeter - the higher the ratio, the more efficient the stream Channel roughness - causes friction, slowing the water down, caused by irregularities in river bed, boulders, trees, vegetation + contact between water and the bed. Channel gradient - slope / steepness = the steeper the gradient the faster the velocity

Question 31

River long-profile

Answer 31

Upper = steep sides, shallow river, v-shaped valley, vertical erosion Middle = steep, deep channel, lateral erosion, gently sloping sides Lower = deeper channel, very wide, almost flat valley, gentle, high rates if deposition

Question 32

Erosional processes: Abrasion Attrition Hydraulic action Solution

Answer 32

Abrasion = (corrosion) is the wearing away of the bank + bed by the carried load. Attrition = the wearing away of the load, creating smaller particles. Hydraulic action = the force of air + water on the sides of the river + cracks. Direct force causes pressure to drop + bubbles to form. Solution = the removal of chemical ions (Ca) dissolving certain types of rocks

Question 33

Factors affecting erosion

Answer 33

Heavier load, fast velocity, steeper gradient, softer rock, acidic water, high rates of deforestation = increased erosion

Question 34

Transportation Processes: Traction Saltation Suspension Solution

Answer 34

Traction = movement of large boulders Saltation = movement of smaller rocks + pebbles Suspension = movement of silt Solution = the minerals dissolved

Question 35

Deposition

Answer 35

Sediment dropped, carried by wind + water. - increases at a shallower gradient = lower velocity - increases with a lower volume of water - increases with a increase in friction between water + channel

Question 36

Interlocking spurs (upper)

Answer 36

Projections of high land that alternate from either side of a v-shaped valley

Question 37

Waterfall (upper)

Answer 37

When a river flows overland that has two different heights + rock types. - Softer rock erodes faster = undercutting harder rock - Leaving an overhang = until it collapses - Fallen rocks crash into plunge pool - Repeated upstream leaving behind a gorge

Question 38

Meander (middle)

Answer 38

A bend in a river channel. - Forms when water erodes the banks of the outside + sediment is deposited on the inside

Question 39

Ox-bow lake (middle)

Answer 39

The neck of the meander gets narrower,eventually cutting it off during a flood, sediment seals it off

Question 40

Floodplain (lower)

Answer 40

An area of land alongside a river prone to flooding = very fertile land due to deposition

Question 41

Levee (lower)

Answer 41

A natural / artificial wall that blocks water. - Formed by repeated flooding (sediment) - Used to create available land or divert a body of water

Question 42

Hydrographs

Answer 42

Shows how a river channel responds to key processes of the hydrological cycle, measures the speed at which rain falling on a drainage basin reaches the river channel Discharge or run-off is plotted against time

Question 43

Factors affecting hydrographs

Answer 43

Channel modifications = channelisation, enlargement, straightening = increases movement of water - lowers lag times (increases carrying capacity) Urbanisation = removal of trees = decreased evapotranspiration + interception = increased runoff (impermeable surfaces) Removal of vege - shorter lag times, increased peak flows, flood risk, runoff and lower carrying capacity. Vege type = winter means fewer leaves , lowers interception