Water Cycle Flashcards
1
Q
what % of water is fresh
A
2.5%
2
Q
how many km² of rivers in the world
A
1 million km²
3
Q
what is the average depth of the ocean
A
3.5km
4
Q
how long does permafrost have to be frozen
A
2 years <
5
Q
how many km² of ice sheets are there
A
50k km²
6
Q
what % of evaporation is from oceans and seas
A
90%
7
Q
what % of evaporation is from transpiration
A
10%
8
Q
time period of shallow groundwater
A
100-200 years
9
Q
time period of deep groundwater
A
10,000 years
10
Q
time period of glaciers
A
20-100 years
11
Q
time period of lakes
A
50-100 years
12
Q
time period of seasonal snow cover
A
2-6 months
13
Q
time period of rivers
A
2-6 months
14
Q
time period of soil water
A
1-2 months
15
Q
how old was ice for ice cores for dating atmoshpheric carbon
A
400k years old
16
Q
how many river gauging stations in the UK
A
1500<
17
Q
how much water is abstracted per day in the UK
A
15k ML/day
18
Q
how many ha of Exmoor Restoration
A
2000 ha
19
Q
how much did water tables rise after the Exmoor restoration
A
2.65cm
20
Q
how much less drainage as a fraction after Exmoor restoration
A
2/3 less water drainage
21
Q
social benefits of Exmoor restoration
A
education and leisure due to reinvigorated wildlife
22
Q
Environmental benefits of Exmoor restoration
A
cleaner water
peat restoration so more carbon stored
biodiversity improved
23
Q
environmental benefits of Exmoor restoration
A
more water in upper course of the river so better for regular habitat
water quality better for wildlife
CO2 storage opportunity
24
Q
what % of the exe catchment is impermeable
A
84%
25
what is a drainage basin
area of land drained by a river and its tribuitaries
26
Define Input
Material or energy moving into a system from outside
27
Define output
Material or energy moving from the system to the outside
28
Define Energy
Power or driving force
29
Define Stores/Components
Individual elements or parts of a system
30
Define flows/transfers
links or relationships between components
31
Define positive feedback
a cyclical sequence of events that amplifies or increases change and exacerbates the outputes of a system, pushing it in one direction and causing environmental instability
32
define negative feedback
a cyclical sequence of events that damps down or neutralises the effects of a system, promoting stability and a state of dynamic equilibrium
33
dynamic equilibrium
represents a state of balance within a constantly changing system
34
what type of system is the LOCAL water cycle
open system
35
what type of system is the GLOBAL water cycle
closed system
36
what % of fresh water is stored in rocks (aquifers)
30%
37
what is the water table
the upper level of saturated water
38
why does the water table change
rises and falls in response to groundwater level change
39
what does the water table need to be kept in
dynamic equilibrium
40
Define precipitation
transfer of water form atmosphere to ground in any form
41
Define evaporation
transfer of water from liquid state to gaseous state of water vapour
mainly from ocean to atmosphere
42
Define condensation
transfer of water form gaseous state to liquid state
mainly in clouds
43
Define interception
precipitation that does not reach the soil but instead meets the leaves of trees or other objects
44
Define overland flow
water that travels across the land surface
45
Define infiltration
transfer of water from the ground surface into soil
46
Define throughflow
water flowing through soil towards a river channel
47
Define percolation
water soaking into rocks
48
Define groundwater flow
transfer of water very slowly through rocks
49
how much higher were sea levels 3 million years ago
50m compared to today
50
How much did sea levels fall during the last ice age
100m compared to today
51
what % of water not in the ocean is stored in ice
95%
52
give an example of a positive feedback loop in terms of sea levels
sea rises ➡️ ice shelves calve➡️sea levels rise further
53
since 1980, what's the rate of arctic sea ice melting per year
12.6%
54
what is the problem with less SEA ice such as in the Arctic
less reflective surface (lower albedo so more energy absorbed)
55
Define albedo
the fraction of light that a surface reflects
56
local factors that drive water cycle change
urbanisation
deforestation
farming
storms
seasons
57
what is lithology
study of general physical characteristics of rocks
"the lithology of Minehead"
58
what is field capacity
the amount of soil moisture/water in the soil after excess water has drained
59
define drainage basin
the area of land that is drained by a river and its tributaries
60
define stemflow
flow of intercepted water down the trunk or stem of a plant
61
define sheetflow
overland flow that is in a continuous sheet (concentrated flow)
62
what is the rate of water flow in Cheddar Gorge
583cm/hr
63
what is the rate of water flow in unconsolidated gravel
up to 20,000cm/hr
64
what is the rate of water flow in sandstone
200cm/hr
65
what % of water is lost to interception in temperate pine forests
from 94% down to 15% (light to heavy rainfall)
66
what % of water is lost to interception in Brazilian evergreen forests
66%
67
what % of water is lost to interception in grasslands
30-60%
68
what is the water balance (equation)
P=Q+E+-S
Precipitation
Q total runoff
Evapotranspiration
Storage (rock and soil)
69
how long is the river Wye
215km
70
why is the river Wye in a special area
AONB due to rich wildlife and is a site of special scientific interest
71
what has changed about the river Wye’s upper basin
steep sides have been deforested for pasture and sheep grazing, reducing interception and increasing overland flow
72
what type of rock is the bedrock in the river Wye basin
impermeable mudstones and shales
73
what is a flashy hydrograph
short lag time and high peak
74
what is a low hydrograph
low and flat with a low peak, larger lag time
75
what causes flashy hydrographs
impermeable rock
Urban land use
Relief
High soil water content
Heavy rainfall
Small basin
Steep relief
76
what causes flat hydrographs
large basins
Permeable rock
Forests (interception)
Gentle relief
Dry soils with low soil moisture
Lighter rainfall Small basin
77
Which storm was December 2015
Storm Desmond
78
when was storm Desmond
December 2015
79
how much rainfall fell in northern England during Storm Desmond
340mm in 24 hours
A UK record
80
which areas were affected by storm Desmond (village)
Glenridding was severely damaged
Inundated by the rain
81
why are hydrgraphs useful
help scientists to plan effectively for flood control
82
when was the major Californian drought
2011 to 2017
83
what happened 2011-2017
majot Californian drought
84
what happened in the Californian drought
river and lakes dried up,
Agriculture declined
Productivity declined
Wildfires consumed lots of vegetation
85
what were agricultural losses during the Californian drought
$5.5 billion
86
how many trees died during the Californian drought
130 million
87
summer precipitation (water)
less overall but more storms
88
summer vegetation (water)
rapid growth so more interception and transpiration
89
summer evaporation (water)
higher temps cause more evaporation
90
summer soil water (water)
dry soils have greater capacity but hard baked soils can increase overland flow
91
summer River channel flow (water)
low flow conditions
92
winter precipitation (water)
greater quantity but less storms and more likelihood of snow
93
winter vegetation (water)
deciduous vegetation dies so less interception and evaporation
94
winter evaporation (water)
lower temps reduce rates
95
winter soil water (water)
soils may become saturated and cause overland flow
96
winter river channel flow (water)
high flow is likely
97
examples of human activities affecting water cycle change
land use change
Farming practices
Water abstraction
98
how does land use change affect the water cycle
urbanisation affects permeability of surfaces and increases overland flow
Deforestation causes soil erosion and reduced interception
Hydrographs therefore become flashier
99
How does land use farming practices affect the water cycle
irrigation and land drainage can affect soil moisture content and teh excess water causes soil erosion and higher discharge rates
100
how does water abstraction affect the water cycle
Abstraction from aquifers can deplete them and over abstraction causes the water table to drop and if it gets below sea level then it can be filled with saline water
101
where in the UK is now highly productive farmland but prone to flooding
Somerset levels
102
where has moorland been drained
near York
103
what are the issues with draining moorland
dries out peat so releases carbon and the peat is vulnerable to erosion (friable) so causes excessive drainage and peat clouds were formed
104
what were the peat clouds called
the “Fen Blows”
105
How many tonnes of carbon do the English peatlands store
584 million tonnes of carbon
106
What is the average rainfall in TRFs
2000mm a year
107
what is the average temperature in TRFs
27 degrees
108
how many people live in the TRFs
over 200 million
109
What proportion of species are found in TRFs
about half
110
what % of the world’s oxygen do TRFs produce
28%
111
What % of rainfall is intercepted by the canopy in TRFs
75%
112
what % of water actually infiltrates the soil in TRFs
sub 25%
113
what % of the worlds rainforests have been wiped out?
50%
114
why has so much rainforest been destroyed?
Commercial farming (cattle ranching and plantations)
Mining
Logging
Settlements
115
What are the issues created by deforestation
little interception so soil leaching, erosion and flooding may occur
116
what happens when forest is replaced by pasture and crops
almost no evapotraspiration occurs causing less atmospheric humidity and therefore less clouds and precipitation
117
