Unit 1 Notes Flashcards
1
Q
Why is water important?
A
Provides freshwater, flows through plants, sustains ecosystems, fisheries, essential for crops and livestock, regulates environment.
2
Q
What % of water is stored in Oceans?
A
97.4%.
3
Q
What % of water is stored in the land and the atmosphere?
A
Land - 2.6%. Atmosphere - 0.001%.
4
Q
How much land flows through global water cycles each year?
A
1,033,000 km cubed.
5
Q
What is water cycle mass balance made up of?
A
Inputs, Outputs, flows, and stores.
6
Q
What are the examples of outputs?
A
Evaporation, Transpiration, channel flow, meltwater, sublimation, wind blown snow.
7
Q
What are the examples of inputs?
A
Avalanche, De-sublimation, Precipitation.
8
Q
What are the examples of flows?
A
Groundwater flow, basal sliding, percolation, interception, infiltration, direct runoff, internal deformation.
9
Q
What are the examples of stores?
A
Oceans, freshwater, atmosphere.
10
Q
What is an open system?
A
A system in which the quantity of water will vary over time.
11
Q
What is a closed system?
A
A system in which the quantity of water is fixed.
12
Q
Why is a drainage basin an open system?
A
Because it receives water from above and below the ground, and consists of inputs, storage, transfers, and outputs.
13
Q
Why is the global water cycle a closed system?
A
Because new water is never added to the earth or the atmosphere, and water is never removed.
14
Q
What is the size of each global water cycle store?
A
Oceans - 1,335,000 km. Crysosphere - 26,000 km. Groundwater - 15,000 km. Rivers - 178 km. Soil moisture - 122 km. Atmosphere - 13 km.
15
Q
What is the main input of global water stores?
A
Precipitation.
16
Q
What % of the water is unusable?
A
30%.
17
Q
What % of water is permafrost?
A
69%.
18
Q
What are the variations in Tundra areas?
A
Fog and rain during summer, as the temperature isn’t high enough for water to evaporate.
19
Q
What are the variations in equatorial regions?
A
High amounts of water, higher rainfall, high evaporation, moist air.
20
Q
What are the variations in glacial areas?
A
68.7% of water is stored in glaciers, so glacial water can’t be used as freshwater.
21
Q
What are the variations in the tropics?
A
They have lots of groundwater, they’re used as safe drinking water.
22
Q
What is sea ice in Europe like now, compared to the devensian?
A
There is no sea ice, large glaciers, or tundra regions in Europe.
23
Q
What was the temperature increase in 2017, compared to pre-industrial levels?
A
1 degree celsius.
24
Q
What was the temperature increase in glacial areas?
A
4 degrees celsius.
25
What does a light albedo mean?
Higher reflection, Lower melting rates, lower melting rates.
26
What has the sea level rise been since 1880?
19.5 cm.
27
What is the ocean rise predicted to be by 2100?
7cm, 60cm in total.
28
How many people live in areas less than 1m above sea level?
250 million people.
29
What are the reasons for the rising sea level?
Run off of meltwater, thermal expansion of seawater as it warms.
30
What was the mean sea level in 2018?
9cm above the 1993 average.
31
What % of sea level rise was due to meltwater, and thermal expansion?
2/3 was meltwater, 1/3 was thermal expansion.
32
What does the water budget affect?
How much water is stored in a terrestrial drainage system over a typical year.
33
What is the equation for precipitation?
Precipitation = Stream flow + Evapotranspiration.
34
What does it mean if P>Q+E?
Positive Balance.
35
What does it mean if P
Negative Balance.
36
What is a soil water surplus?
Excess water in the system, soil is saturated. Precipitation exceeds evapotranspiration, excess isn't being used by plants.
37
What months is there a soil water surplus in the UK?
January, February, March, April, May, November, December.
38
What is soil water utilisation?
A reduction in water available within the system, as evapotranspiration exceeds transpiration. Plant growth increases transpiration rates, increasing temperature increases evaporation.
39
What months is there soil water utilisation in the UK?
May, June, July, August, September.
40
What is soil water recharge?
Precipitation exceeds evapotranspiration after a period if soil water deficiency. Increase of water in the soil.
41
What months do we have soil water recharge in the UK?
September, October, November.
42
What is field capacity?
Soil is at the maximum amount it can hold before becoming saturated, as precipitation.
43
What is the water budget in New York?
There is lower evapotranspiration, soil is always saturated.
44
What is the water budget in Texas?
There is a positive water budget from November-March, allowing recharge. Soil water utilisation from March-May.
45
What are the different types of precipitation?
Rain, Ice, Sleet, Snow, Hail, Dew, Fog, Mist.
46
What is the effect of a prolonged period of intense rainfall on drainage basins?
Infiltration, soil becomes saturates, increased surface storage, surface runoff, increased throughflow, groundwater flow.
47
What is the effect of a short period of light rain on drainage basins?
Interception, infiltration, most of precipitation is intercepted by vegetation, evaporation takes place, no effect on channel flow.
48
What is the first surface that precipitation reaches?
Plants.
49
How do levels of interception loss vary in deciduous woodland in winter and summer?
Winter - Deciduous trees lose their leaves, lower interception loss. Summer - Higher temperatures, more evaporation, high interception loss.
50
What happens in a varied landscape?
There are low levels of interception where there is no high lying shrubs, high levels of interception.
51
How is precipitation stored on the surface?
Water frozen as snow or ice, water accumulating in depressions, infiltration is slower than input of water.
52
What is infiltration capacity affected by?
Permeability of soil.
53
How does the texture of the soil control permeability?
Coarse textures soil causes high rates of infiltration. Fine textures soil causes low rates of infiltration.
54
Which other factors affect permeability of soil?
The size of weathered rock particles, controlling the size of pore spaces within soil.
55
Which other factors affect infiltration rates?
Soil compaction, types of vegetation.
56
How does the amount of moisture vary?
Varies with time linked to individual precipitation events.
57
What is Gravitational Water?
The amount of water in the soil that percolates under the influence of gravity, reaching the water table.
58
What is Retained Water?
Water held in pores small enough to hold water against gravity, not tightly enough so roots can't absorb.
59
What is hygroscopic water?
Tightly held water on soil particle surfaces as a result of adhesion.
60
When will soil be in wilting point?
In august and summer months, and months of outputs>inputs.
61
What do trees affect levels of?
Gravitational water, retained water.
62
How do trees affect gravitational water?
Water moves by sticking together when in trees, and is dragged to the leaf.
63
How do trees affect retained water?
Forests retain excess rainwater, moderate runoff patterns, and prevent extreme runoff.
64
How do trees reduce flood risk in an area?
Slowing down rainwater, reducing erosion, making it more likely to infiltrate and percolate.
65
How does gravitational water create ground water?
It percolates downward to create a saturated zone in rock.
66
What must bedrock be, for groundwater to flow?
Permeable, contain pore spaces, contain joints/cracks.
67
What is an aquifier?
Rock that is capable of storing and transmitting water.
68
What is an aquiclude?
Rock that isn't capable of storing and transmitting water.
69
What are the impermeable rocks?
Granite, Clay.
70
What are the permeable rocks?
Sandstone, Chalk, Limestone.
71
Which rock is pervious?
Limestone.
72
Which rocks are porous?
Sandstone, chalk.
73
What type of weather leads to high evaporation?
High temperatures, low humidity, high wind speeds.
74
Which factors control the rate of transpiration?
Temperature, high light intensity, humidity, wind speed, pressure, availability of water.
75
What is the most important output of a drainage basin?
Evapotranspiration - 100% of output in arid regions. 75% of output in humid areas.
76
What is the largest output from a drainage basin?
Water flowing through a river.
77
What is a river regime?
Discharge flowing through a river over a year has a predictable pattern.
78
What is a simple regime?
A clear seasonal difference between periods of high water levels and low water levels.
79
What is a complex regime?
Pattern of discharge has multiple peaks and more variable flow.
80
How is discharge measured?
Cubic metres per second.
81
Which natural factors affect the pattern of a river regime?
Shape of surrounding area, rainfall, amount of vegetation, patterns of precipitation, evapotranspiration, rock type.
82
Which human factors affect the pattern of a river regime?
Amount of vegetation, land use, building infrastructure, flood defences, extracting water from rivers.
83
What is the River Severn like in winter?
Discharge peaks at 125 cumecs, because temperatures are at their lowest at this time of year, reducing rates of evapotranspiration. Trees have less leaves.
84
What is the River Severn like in Spring?
Discharge peaks at 60 cumecs because temperatures start to increase, so rates of evapotranspiration increase. Trees gain leaves, rates of infiltration increase.
85
What is the River Severn like in Autumn?
Discharge increases because temperatures start to decrease, causing soil water recharge. Temp goes from 20 in summer to 10 in autumn. Rates of evapotranspiration decrease.
86
What is the River Severn like in Summer?
Discharge is at its' lowest of 20 cumecs, temperature is at its' highest, rates of evapotranspiration are high. Trees have all their leaves, infiltration is at its' highest.
87
What is River Severn rainfall distribution similar to?
Rainfall is evenly distributed, high evapotranspiration in summer leads to low runoff.
88
What is glacier melt?
European mountain rivers have a high water period, when glaciers feeding melt most rapidly.
89
What is tropical seasonal rainfall?
In tropical areas, evapotranspiration tends to be stable, but summer rain causes a peak.
90
When does the river Po peak and trough?
Peaks in May and November, troughs in January and August.
91
What happens to the River Po in January-May?
Ablation of glaciers, melting of snow in the alps.
92
What happens to the River Po in May-August?
Warmer temperatures, increased plant growth, snow has disappeared, more evapotranspiration.
93
What happens to the River Po in August-November?
Temperatures start to drop, more water in river channel.
94
What happens to the River Po in December?
Precipitation falls as snow, doesn't enter river. Water is stored, doesn't runoff.
95
What is the background of the Colorado river?
It flows through an arid region - peak rainfall is in August, due to intense rainfall storms.
96
What was the hoover dam designed to do, and when was it built?
A source of power generation, flood control, water storage. Built in 1936.
97
What happened before the construction of the dam?
River ranged from 5 to 80 cubic metres per second.
98
What was the impact of the dam?
River ranged from 10 to 20 cubic metres per second.
99
What are the characteristics of flashy hydrographs?
Short lag times, steep rising and falling limb, high peak discharge.
100
What are the characteristics of non-flashy hydrographs?
Long lag times, shallow rising and falling limbs, low peak discharge.
101
What are the conditions of flashy hydrographs?
High drainage density, granite, field capacity, rapid thaw, short torrential downpour, steep sided valley, round shaped drainage basin, urban area.
102
What are the conditions of non-flashy hydrographs?
Steady rain, gently sloping valley, low drainage density, elongated drainage basin, rural area, chalk, soil below field capacity, gradual thaw.
103
Which other factors affect hydrographs?
Catchment shape, drainage density, slope gradient.
104
How does catchment shape affect hydrographs?
Elongated drainage basins have lower peak discharge at head of basin, circular drainage basins take less time to reach the river.
105
How does drainage density affect hydrographs?
The total length of streams per unit area of land. High drainage density has a short lag time, steep falling limb, water drains out quickly.
