river Flashcards
1
Q
What is precipitation
A
When water falls from the sky (eg rain, snow sleet)
2
Q
What is evaporation
A
The process of turning from a liquid to a vapour
3
Q
What is condensation
A
The process where water vapour becomes liquid
4
Q
What is interception
A
When leaves on trees catch precipitation when it falls
5
Q
What is surface runoff
A
When water runs along the surface of the ground
6
Q
What is a permeable rock
A
a rock that allows water to soak into it
7
Q
What is throughflow
A
When water flows sideways through the soil towards the river
8
Q
What is an impermeable rock
A
a rock that will not allow water to soak into it
9
Q
What is the source
A
The starting point of a river usually in the hills
10
Q
What is the confluence
A
The point where two rivers meet
11
Q
What is a tributary
A
a smaller river that joins onto a larger one
12
Q
What is the watershed
A
An imaginary line that separates one drainage basin from another
13
Q
What is a floodplain
A
Flat land at the sides of a river that gets flooded when a river overflows
14
Q
What is the mouth
A
where a river flows into a lake sea or ocean
15
Q
What is a drainage basin
A
The area of land drained by a river and its tributaries
16
Q
What is a river channel
A
Where the river flows
17
Q
What is a river bank
A
The side of a river channel
18
Q
What is a river bed
A
The bottoms of a river channel
19
Q
What is erosion
A
The wearing away and removal of material by force
20
Q
What is hydraulic action
A
The power of the water as it smashes against the river banks, air becomes trapped in the cracks of the river bank and bed causing the rock to break apart
21
Q
What is abrasion/ corrasion
A
When pebbles and stones scrape the bed and banks of a river and wear it away
22
Q
What is attrition
A
When rocks and stones knock against eachother and break down into smaller pieces
23
Q
What is solution (corrosion)
A
When slightly acidic water dissolves certain types of rocks eg limestone
24
Q
What is weathering
A
The breakdown and decay of rock by natural processes without the involvement of any force and it occurs in place eg elements of the weather
25
What is transportation
The movement of a rivers load (eroded material carried by the river)
26
What is deposition
The laying down (dropping) of material being carried by a moving force, such as a river or waves
27
What is physical weathering
Water from precipitation entering the crevices and cracks in rock, followed by changes in temperature causing water to freeze and thaw, exerting pressure on rocks as water turned to ice expands within cracks physically breaking rocks apart
28
What is chemical weathering
Slightly acidic rain seeps into porous rocks causing certain rocks to decay and disintigrate
29
What is biological weathering
The roots of plants especially trees, growing in cracks in rocks gradually breaking the rocks apart. This is also accelerated by burrowing animals
30
What is suspension
Fine material such as sand and soil are carried by the flow of the river
31
What is saltation
Small stones and pebbles bounce along the river bed
32
What is traction
Heavier materials such as heavy rocks are rolled along the river bed
33
What is a hydrograph
a graph that shows how a rivers discharge has changed following a storm event
34
What is discharge
The volume of water flowing through a river channel at any given point
35
What is a river regime
The variation in river discharge throughout a year
36
How would human impact influence the water cycle
Deforestation reduces the evapo transpiration transfer and reduces interception
Global warming - melts ice sheets and glaciers increasing the fresh water store also increases evaporation and precipitaion
37
What is infiltration
Process by which water on the ground surface enters the soil
38
What is percolation
The downward movement of water from the soil into the rock beneath
39
What is transpiration
Where water evaporates into the atmosphere through plants
40
What is evapotranspiration
The sum of all processes by which water moves from the land surface into the atmosphere via evaporation and transpiration
41
What is peak discharge
The maximum amount of water held in the channel
42
What is peak rainfall
The maximum amount of rainfall
43
What is lag time
The time taken between the peak rainfall and peak discsharge
44
What is the rising limb
It showeds the increase in discharge on a hydrograph
45
What is the falling limb
It shows the return of discharge to normal ( base flow) on a hydrograph
46
What is the base flow
The normal discharge of the river
47
What are some factors affecting river regime
Climate
Land use
Geology
vegetation
48
What is a valley
Long low areas that can typically be found between hills and mountains
49
What is a v shaped valley
A valley shaped like a v created by vertical erosion from a river
50
what is the long profile of a river
It shows how the gradient changes as a river flows from source to mouth
51
What is a cross profile
The shape of the river valley at a particular point
52
what is a v shaped valley
A steep sided valley formed by a river in its upper course, it has a narrow floor and steep slopes due to vertical erosion
53
What is a meander
a bend in the river
54
What is a plunge pool
A deep depression in the riverbed at the base of a waterfall created by erosion of soft rock
55
What are interlocking spurs
Projections of high land that alternate from either side of a v shaped valley
56
What is a valley
A low area of land between hills or mountains often with a river flowing through it
57
What a gorge
a steep narrow valley with nearly vertical walls formed by the retreat of a waterfall
58
What is an oxbow lake
a crescent shaped lake formed when a meander of a river is cut off from the main river channel
59
Define levee
Embankments at the sides of a river channel build up over time after repeated flooding
60
What is a meander scar
a feature formed by the drying up of an oxbow lake indicating the previous position of a meander bend
61
What is the Bradshaw's model
a geographical model that shows how a rivers characteristic varies between the upper and lower course
62
Describe the formation of v shaped valleys
As the river flows down steep gradients it erodes vertically, weathering breaks up and loosens the soil and rock, one common type of weathering in upland areas is freeze thaw. The loosened material creeps down because of gravity in a process called soil creep and is washed away into the river. Overtime resulting in a v shaped valley
63
Explain the formation of a waterfall
Waterfalls are formed when a river flows over hard rock overlaying softer rock, the softer rock is eroded quicker by hydraulic action and abrasion. This creates a drop, over time the channel deepens forming a deep plunge pool. Over time the hard rock is undercutting, and eventually falls into the plunge pool causing the waterfall to retreat upstream forming a steep sided gorge.
64
Explain the formation of a levee
During a flood the velocity of the water decreases as it spreads out onto the floodplain due to friction. Reduces the river's ability to carry materials, resulting in the deposition of larger material closest to the river and the deposition of finer material further away. Over time these layers of sediment build up creating embankments known as levees
65
Explain the formation of a river meander
a river meander forms through a process of erosion and deposition. The faster moving water on the outside of the bend erodes the bank, creating a steep cliff, while the slower moving water on the inside deposits sediment forming a slip off slope. Over time this cycle repeats causing the vend to become more pronounced and the rivers course to gradually shift towards the outside of the bend forming a meander
66
What is a river cliff
A steep bank on the outside of a river bend where the river erodes the bank
67
What is a slip off slope
A gentle area on the inside of a rivers meander that forms when sediment is deposited by slower moving water
68
What is aquifer
A body of rock and that holds groundwater
69
Why are some areas in surplus
Higher latitudes/ equator - high rainfall
Lower rates of evaporation
Low population density
70
Why are some areas in deficit
Low rainfall/ high evaporation
High population density / demand
71
What is a borehole
A narrow hole in the ground constructed by a drilling machine in order to gain access to the groundwater system
72
What is eutrophication
When excess nutrients are added to the water from fertiliser, algal bloom covers the surface blocking sunlight from reaching the river bed stopping plants in the water to be able to photosynthesise.bacteria break down the plants and consume oxygen resluting in anoxia causing aquatic life to die
73
Explain one way sewage can affect water quality
Discharge of sewage lower water quality threatening human life
74
Explain one way agriculture can affect water quality
Agriculture affects water quality, through the release of nutrients from fertiliser / pesticides into a water environment. Therefore contaminating the water
75
What is chlorination
chlorine is added to the water to kill bacteria and algae
76
What is filtration
It is used to remove suspended solids in the water
77
What is sedimentation
It is used to remove very fine sediments
78
What is aeration
Air is added to remove dissolved iron and manganese
79
What is disinfection
It is used to kill bacteria
80
What is river restorastion
When you return a river which has been altered by human intervention back to its natural state
81
What is afforestation
When trees are planted near to the river to increase interception and lower river discharge
82
What is channel straightening
Removing meanders from a river to make the river straighter
83
What is the use of a dam
The dam traps water which builds up behind it forming a reservoir water can now be released in a controlled way
84
What is a flood relief channel
The floodwater flows into the relief channel and is taken either to an area where it can be absorbed or re enters the river further down its course
85
What is flood plan zoning
Categorising land into flood risk zones to minimise the impact of flooding
86
What is flooding
When the amount of water moving in a river exceeds the capacity of the channel
87
What is the primary purpose of the Kildare Water Scheme?
To provide a reliable supply of water to the residents of Kildare.
