The Water Cycle

Question 1

Hydrological Cycle

Answer 1

The continual movement of water between the rivers, oceans, atmosphere and land

Question 2

How the water cycle works

Answer 2

1) evaporation
2) warm air rises
3) condensation
4) precipitation
5) interception
6) surface run off or through flow
7) percolates

Question 3

Major stores of water

Answer 3

Ocean, ice caps, land and atmosphere

Question 4

Transfers

Answer 4

Movement of water between stores

Question 5

River or drainage basins

Answer 5

An area of land drained by a river and its tributaries

Question 6

Edges of drainage basin

Answer 6

Watershed

Question 7

Where the river meets the sea

Answer 7

Mouth of the river

Question 8

Types of erosion

Answer 8

Abrasion
Attrition
Hydraulic Action
Corrosion/solution

Question 9

Abrasion

Answer 9

Material carried by the river wears away the bed and banks

Question 10

Hydraulic action

Answer 10

The power of the water forces air into gaps in the banks and weakens them so they eventually collapse

Question 11

Attrition

Answer 11

The particles carried by the river are bashed against one another, making them smaller and rounder

Question 12

Corrosion/solution

Answer 12

Particles are dissolved because of slightly acidic solution

Question 13

Causes of vertical erosion

Answer 13

Swirling currents creating potholes in the river bed

Water falls creating plunge pools

Question 14

Types of transportation

Answer 14

Traction
Saltation
Suspension
Solution

Question 15

Traction

Answer 15

Rolling large stones along the bed of the river

Question 16

Saltation

Answer 16

Bouncing smaller particles along the bed

Question 17

Suspension

Answer 17

Sediment that floats within the river flow

Question 18

Solution

Answer 18

Minerals dissolve in the water

Question 19

Deposition

Answer 19

When the velocity of the river falls, it has less ability to carry its load. The river then starts to drop the material, starting with the largest particles. Loss of velocity can occur for many reasons

Question 20

Reasons for the loss of velocity

Answer 20

River enters the sea or lake
There is less water entering the river
There is more sediment in the river

Question 21

Competence

Answer 21

The maximum size of material the river is capable of carrying

Question 22

Capacity

Answer 22

The total actual load transported

Question 23

Levels of energy required to erode

Answer 23

Sands require the least energy as their particles do not coagulate
Silt/Clay requires a higher velocity as particles do coagulate
Pebbles are eroded at higher velocities
Boulders require the highest velocities to erode

Question 24

Upper course vs lower course

Answer 24

Upper course: Steep gradients lead to rapid-flowing rivers
Middle course: River meanders through gentle gradients
Lower course: River braids over flat land

Question 25

Upper course

Answer 25

- Vertical erosion - Weathering - Headward erosion - Boulders create friction, slowing down the rate of flow - Steep gradient

Question 26

Characteristics commonly found in the upper course of rivers

Answer 26

- V-shaped valleys - Potholes - Interlocking spurs - Waterfalls - Rapids - Gorges - Large boulders

Question 27

Middle course

Answer 27

``` Lateral erosion Transportation Asymmetrical channel Floodplain Truncated spurs Meanders ```

Question 28

Lower course

Answer 28

Transportation Deposition Friction is reduced, so greater velocity

Question 29

Characteristics commonly found in the lower course of rivers

Answer 29

``` Wide smooth channel Braiding Oxbow lakes Large floodplain Terraces Levees Deltas ```

Question 30

V Shaped Valleys

Answer 30

Weathering breaks up material on slopes, which is then deposited into the river. Material is carried by riverbed through abrasion

Question 31

Waterfalls

Answer 31

Soft rock erodes more quickly, undercutting the hard rock Hard rock is left overhanging, because it isn't supported it eventually collapses. Plunge pool is created by the erosion of rocks. Process repeats and waterfall moves upstream, forming a steep sided gorge on either side

Question 32

Meanders

Answer 32

Meanders are formed by erosion and deposition. Centrifugal force causes the water to flow fastest around the outside of the river, creating erosion on the outside and deposition on the inside bend.

Question 33

Oxbow Lakes

Answer 33

When the bends of a meandering river become so large that the water takes a more direct path, often cutting through the land of the bend. This may change the course of the river as more water runs through the alternate route. The old bend of the river eventually gets cut off, leaving an oxbow lake.

Question 34

Braiding

Answer 34

River loses velocity, sediment is deposited and builds up to choke the main channel, causing the river to split in a braiding pattern.

Question 35

Formation of a delta

Answer 35

- River carrying sediment reaches sea/lake - Loses energy and deposited material - Heaviest sediment first, more sediment is added - if tides are strong then sediment will be washed away, if not then delta will form

Question 36

Flocculation

Answer 36

When the fresh and salt water meet creating an electric charge causing the clay particles to coagulate

Question 37

Types of delta

Answer 37

Birds foot: Many distributaries Cuspate: Sediment spread evenly on either side Arcuate: Rounded and convex structure

Question 38

Physical causes of flooding

Answer 38

- Heavy rainfall - Snowmelt - Steep slopes - Impermeable rock - Very saturated soils - Compacted or dry soils

Question 39

Human factors that cause flooding

Answer 39

Urbanisation | Deforestation, removing trees reduces the amount of water intercepted and increases runoff

Question 40

Storm Hydrographs

Answer 40

shows how rainfall events change the discharge of a river

Question 41

Factors influencing storm hydrographs

Answer 41

``` Basin size Precipitation type Temperature Land use/ Urbanization Rock/Soil type Drainage density Tides/storm surges ```

Question 42

Drainage density formula

Answer 42

Total length of all streams and rivers in a drainage basin, divided by the total area of the drainage basin

Question 43

Factors affecting drainage density

Answer 43

``` Geology Land use Time Precipitation Relief ```

Question 44

Bifurcation ratio meaning

Answer 44

a LOW bifurcation ratio means a HIGHER risk of flooding

Question 45

Bifurcation ratio

Answer 45

Number of streams of one order in relation to the number of streams in the next order (1st order / 2nd order) then finding the average of all the ratios

Question 46

Hydraulic radius

Answer 46

Ratio between the area of a cross section of a river channel, and the length of its wetted perimeter.

Question 47

Purpose of the hydraulic radius

Answer 47

Determines the efficiency of a river. ...

Question 48

Drainage patterns

Answer 48

Trellised Radial Parallel Dendritic

Question 49

Radial

Answer 49

Streams radiate outwards from a central high point

Question 50

Trellised

Answer 50

Tributaries enter the main river approximately 90 degree angles due to ridges of harder or impermeable rock, causing a trellis-like appearance of the drainage system

Question 51

Parallel

Answer 51

Rivers flow uniformly down steep sloping surfaces

Question 52

Dendritic

Answer 52

Streams join together to form tributaries into the main river. From overhead this makes a tree-like pattern with tributary "branches" and a river "trunk."