Theme 2 - Rivers Flashcards

You may prefer our related Brainscape-certified flashcards:
1
Q

water cycle

evaporation

A

sun’s energy warms oceans and lakes, turning it into water vapor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

water cycle

transpiration

A

Water evaporates from the leaves of plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

water cycle

evapotranspiration

A

water moving from the surface into the atmosphere through evaporation + transpiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

water cycle

condensation

A

The water vapor rises, cools, and condenses into clouds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

water cycle

precipitation

A

The water falls back to Earth as rain, snow, sleet, or hail

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

water cycle

surface runoff / overland flow

A

water that flows over the land’s surface and into bodies of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

water cycle

interception

A

water is caught / intercepted
by vegetation such as trees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

water cycle

infiltration

A

water seeps into the ground through the soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

water cycle

throughflow

A

the movement of water through the soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

water cycle

percolation

A

water seeping through permeable rocks beneath the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

water cycle

groundwater flow

A

moving water that has seeped into the ground and is stored in aquifers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

water cycle

aquifer

A

a body of rock and/or sediment that holds groundwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

water cycle

surface storage

A

water held on the Earth’s surface in lakes, ponds, and puddles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

water cycle

fastest flow of water

A

throughflow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

water cycle

slowest flow of water

A

groundwater

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

water cycle

impermeable rock

A

rock that doesnt allow water to pass through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

water cycle

permeable rock

A

rock that allows water to pass through

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

drainage basics

source

A

where the river begins, up in the mountains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

drainage basics

mouth

A

the point where the river ends, flowing into the sea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

drainage basics

confluence

A

where two river channels meet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

drainage basics

tributary

A

small channels that branch off from the main channel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

watershed

A

the boundary of the drainage basin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

drainage basics

floodplain

A

a generally flat area of land next to a river or stream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

river basics

discharge

A

the volume of water that flows through a river channel in a given time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

river basics

load / bedload

A

the sediment that moves along the bottom of a river or stream, carried by the force of flowing water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

river basics

silt

A

fine-grained dirt, soil, or sediment that rivers carry and drop along their courses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

river basics

long profile

A

a line that shows the slope of a river from its source to its mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

river basics

cross profile

A

a section taken sideways across the river channel or valley

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

river basics

gradient

A

a measure of how steeply it loses height

30
Q

river basics

velocity

A

how fast the flow of water of a river is moving

31
Q

river long profiles

downstream

A
  • greater discharge
  • greater width
  • greater depth
  • greater velocity
  • greater load quantity
  • smooth bed
  • smaller load size
  • flat relief/gradient
32
Q

river long profiles

upstream

A
  • less discharge
  • smaller width
  • shallower
  • slower velocity
  • less load
  • rough bed
  • larger load size
  • steep gradient
33
Q

erosion processes

hydraulic action

A

the sheer power of the water as it smashes against the river banks

34
Q

erosion processes

abrasion

A

river’s flow, pebbles, and stones wear away the river’s banks and bed

35
Q

erosion processes

corrosion / solution

A

certain types of rocks, like limestone or chalk, dissolve in a river’s water

36
Q

erosion processes

attrition

A

rocks and pebbles in a river’s flow collide with each other

37
Q

erosion processes

factors influencing the speed of erosion

A
  • faster velocity = more erosion
  • steeper slope = more erosion
  • more acidic water = more erosion (solution)
38
Q

transportation processes

traction

A

large, heavy rocks are rolled or dragged along the river bed

39
Q

transportation processes

saltation

A

small rocks and pebbles bounce along the river bed

40
Q

transportation processes

suspension

A

the carrying of fine, light particles in the water

41
Q

transportation processes

solution

A

when certain types of rock, like limestone or chalk, dissolve in a river’s water and are carried along

42
Q

deposition in rivers

A
  • greatest in the lower course
  • heaviest particles deposit first
  • occurs in low energy water / low velocity
  • inner bend of river
  • forms slip off slope
43
Q

upper course features

A
  • v shape valley
  • steep relief
  • interlocking spurs
44
Q

upper course features

interlocking spurs

A

extend from opposite sides of a V-shaped valley, creating a zip-like pattern

45
Q

upper course features

pot hole

A

a circular depression in a river bed or exposed rock layer that is formed by vertical erosion

46
Q

upper course features

rapids

A

areas of a river or stream where the water flows quickly and shallowly over rocks

47
Q

upper course features

formation of a waterfall explained

A
  1. river’s sediment erodes softer rock, e.g. sandstone or limestone
  2. river undercuts hard rock, creating an overhang that eventually collapses
  3. falling water creates a plunge pool at the base of the waterfall.
  4. falling water and sediment erode the plunge pool, causing more erosion.
  5. waterfall retreats upstream as the soft rock erodes further.
  6. a steep-sided gorge forms behind the retreating waterfall.
48
Q

hard rock example

A

granite

49
Q

soft rock example

A

limestone

50
Q

upper course features

overhang

A

when erosion undercuts rock, leaving rock hanging over, unsupported

51
Q

upper course features

undercut

A

the process of erosion on the lower layer of rock

52
Q

upper course features

plunge pool

A

deep pool of water at the base of a waterfall that’s formed by erosion from falling water, rocks, and other sediment

53
Q

middle course features

A
  • u shaped valley
  • gentle hills
  • meanders
54
Q

middle course features

meander

A

a bend in the river

caused by deposition and erosion on the inner and outer bends of the river, due to the thalweg.

55
Q

where does erosion occur?

A

outside bend

line of greatest velocity

“thalweg”

creates river cliff due to undercutting

56
Q

middle course features

oxbow lake formation explained

A

when the meander neck is broken through by erosion and deposition causes sediment to built up, separating the original channel from the previous meander.

eventually, the previous meander will be completely separate from the channel.

this is called an oxbow lake

57
Q

middle course features

marsh

A

wetlands that form in shallow areas along the edges of lakes, rivers, or seas.

58
Q

lower course features

A
  • flat floodplains
  • deltas
  • levees
  • flat relief
59
Q

lower course features

delta

A

landforms that form when a river or other body of water slows down and empties into a larger body of water, such as an ocean or lake

this results in mass deposition of sediment

60
Q

middle course features

formation of delta explained

A
  1. As a river approaches a larger body of water, its velocity decreases, causing it to lose the ability to carry sediment
  2. The river drops the sediment it’s carrying at its mouth, creating a deposit
61
Q

middle course features

levee

A

natural embankments on the sides of rivers

62
Q

middle course features

formation of levee explained

A
  1. When the river floods, the sediment spreads out across the floodplain.
  2. friction between the ground + water causes it to slow down, depositing the most heavy sediment first
  3. this eventually builds up, forming embankments made up of deposited sediment
63
Q

causes of river hazards

A
  • steep/very flat relief
  • hard baked soil (drought)
  • deforestation/lack of vegetation
  • underlying impermeable rock
  • urbanisation
64
Q

features of a hydrograph

A
  • rising limb
  • faling/recessional limb
  • lag time
  • peak rainfall
  • peak discharge\flashy rivers rise faster and higher
  • flat rivers have a longer lag time
65
Q

flooding management

hard engineering

A
  • dams
  • storage reservoirs + channels
  • dredging
  • embankments + levees
  • flood walls
  • straightening / channelisation
66
Q

flooding management

soft engineering

A
  • wetland / marsh management
  • afforestation
  • land use zoning
  • sandbags
  • evacuation warnings
67
Q

opportunities of living near a river

A
  • fertile soil (alluvium)
  • drinking water
  • tourism + leisure
  • transportation route
  • floodplain provides flat land
68
Q

CASE STUDY: Opportunities + Hazards - Ganges River in Bangladesh

Introduction

A
  • 2,510km long
  • flows through India and Bangladesh
  • drainage basin covers 1.2 million km2
  • source is in himalayan mounters
  • mouth enters the bay of bengal
69
Q

CASE STUDY: Opportunities + Hazards - Ganges River in Bangladesh

Opportunities

A
  • water supply
  • agriculture + fishing -> flooding leaves alluvium which is very rich in nutrients
  • sacred to hindus
  • rafting and river cruises are popular among tourists
  • flat flood plains are easy to build on
  • many dams along the river that provide HEP
70
Q

CASE STUDY: Opportunities + Hazards - Ganges River in Bangladesh

Hazards

A
  • regular floods
  • 1998: 75% of bangladesh flooded, 30 million made homeless
  • these floods cause deaths and the loss of agriculture + crops
71
Q

CASE STUDY: Flood Hazard Management - Ganges River in Bangladesh

Introduction

A
  • 2,510km long
  • flows through India and Bangladesh
  • drainage basin covers 1.2 million km2
  • source is in himalayan mounters
  • mouth enters the bay of bengal
72
Q

CASE STUDY: Flood Hazard Management - Ganges River in Bangladesh

Management

A
  • better flood forecasting + warning systems
  • well stocked food shelters
  • constructing levees + embankments
  • 5000 flood shelters built
  • dams to store water