water and carbon cycle Flashcards
1
Q
what is the definition of a closed system?
A
a system in which the amount of matter remains constant, but in which energy and matter can be transferred as an input, output or flow
2
Q
what is the definition of an open system?
A
a system in which energy and matter can be transferred in, through and out (beyond the boundary of the system).
3
Q
what is input?
A
energy and/or matter entering a system
4
Q
what is output?
A
energy and/or matter leaving a system
5
Q
what is a store/ component?
A
a section of the system in which matter can remain, be added to or removed from.
6
Q
what is the definition of a flow/transfer?
A
movement between stores/components in a system
7
Q
what is a boundary?
A
the edge of a particular system
8
Q
what is positive feedback?
A
occurs within a system where a change causes a further or snowball effect, continuing or even further accelerating the original change; the affects amplified
9
Q
what is negative feedback?
A
original change is reduced or reversed
10
Q
what is atmospheric water?
A
water found in the atmosphere; mainly water vapour with some liquid water (clouds and rain droplets) and ice crystals
11
Q
what is the cryosphere?
A
water locked up on the earths surface as ice
12
Q
what is the hydrosphere?
A
a discontinuous layer of water at or near the earths surface. it includes all liquid and frozen surface waters, groundwater held in soil and rock and atmospheric water vapours
13
Q
what is oceanic water?
A
the water contained in the earths oceans and seas but not including inland seas such as the caspian sea
14
Q
what is terrestrial water?
A
this consists of groundwater,soil moistiure, lakes, wetlands and rivers
15
Q
what are the 4 major water stores?
A
-lithosphere
-atmosphere
-hydrosphere
-cryosphere
16
Q
how much ocean water is there?
A
covers 72% of the earths surface
17
Q
how much of the earths water is in the oceanic water stores?
A
97%
18
Q
what are the types of terestrial water stores?
A
-surface water
-groundwater
-soil water
-biological water
19
Q
what is surface water?
A
is the free flowing water of rivers as well as lakes
20
Q
what is groundwater?
A
water that collects underground in the pore spaces of a rock
21
Q
what is soil water?
A
water that is stored in the soil and is available for growing crops
22
Q
what is biological water?
A
all of the water stored in plant and animal matter
23
Q
how long does water stay in deep ground water stores?
A
10 000 years
24
Q
how long does water stay in shallow groundwater stores?
A
100-200 years
25
how long does water stay in lakes?
50-100 years
26
how long does water stay in glaciers
20-100 years
27
how long does water stay in seasonal snow cover?
2-6 months
28
how long does water stay in rivers?
2-6 months
29
how long does water stay in soil water stores?
1-2 months
30
what states does water exist in?
-solid ice
-liquid water
-gas (water vapour)
31
what state does atmopsheric water usally exist in?
gas
32
what is sublimation?
water changes directly from solid into gas without becoming liquid
33
what is deposition?
where gas turns into solid without becoming liquid
34
what is latent heat?
when water is evaporated it changes its state from a liquid to a gas. this needs energy called latent heat to be extracted from the environment causing a drop in temperature
35
what does the ITCZ stand for?
intertropical convergance zone
36
what kind of weather do you get in the ITCZ?
rain and high temperatures
37
what is accumlation?
the build-up of a glacier due to snow being compacted into ice
38
what is ablation?
the melting of the ice, mainly during summer months, and usually at the snout end of the glacier
39
what is the most recent glacial period known as?
the quaternery glaciation
40
what are glacial periods?
when due to the volume of ice on land sea levels was about 120m lower than currently
41
what are interglacial periods?
when global ablation exceeds accumulation and the hydrological cycle as we know it today returns
42
what is the formation of rain?
-clouds are made up of tiny water droplets
-the water dropeltsgrow and become too heavy and so they fall through the clouds
43
how does drizzle form?
-cloud must be fairly low to the ground
44
how does snow form?
-forms when tiny ice crystals in clouds stick together to become snowflakes
-and they become heavy enough to fall to the ground
45
how does sleet form?
frozen rain that partially melts as it falls
46
how is hail formed?
-forms in thundercloud when drops of water are continuoiusly taken up and down
-when they get really big the updraughts in the cloud cant hold them anymore
47
how is dew formed?
-forms when the temperature of a surface cools down to a temperature that is cooler than the dew point of air next to it
-the water condenses
48
how does frost form?
depositing water vapour to a surface cooler than 0 degrees
49
what is the drainage basin?
the area of land drained by a river and its tributiaries. it includes water found on the surface, in the soil in near-surface geology
50
what is confluence?
occurs when 2 or more flowing bodies of water join together to form a single channel
51
the grrenland ice sheet:
-second largest body of ice, containing 8% of total global freshwater
-if the entire 2,850,000 cubic kilometers melted it would lead to a global sea level rise of 7.2m
-melting is starting much earlier in the year
-2016 and early melting event occured on april 10th until april 15th
52
what is the global water cycle?
all the water on the planet, including all of the drainage basins. it is a closed system
53
what is a hillslope drainage basin?
the water moving in one part of a drainage basin;localised characteristsics mean that the rates of movement in two adjoining drainage basins or tribituaries can differ in spite of their close proximity
54
what is hillslope scale?
localised transfers operating on a small section of land within a drainage basin
55
transport within the global water cycle:
-40 units are exchanged between water & land
-land precipitation contains 114 units, showing that there is considerable recirculation of water over continents
-water in pacific oceans is largely recirculated back into the same ocean
-water from the atlantic and indian ocean is exchanged more
56
what is interception storage?
the precipitation that falls on the vegetation surfaces or human-made cover and is temporarily stored on these surfaces
57
what is overland flow?
the tendancy of water to flow horizontally across land surfaces when rainfall has exceeded the infiltration capacity of the soil and all the surface stores are full to overflowing
58
what is percolation?
the downward movement of water with the rock under the soil surface, rates vary depending on the nature of the rock
59
what is run-off?
all the water that enters a river channel and eventually flows out the drainage basin
60
what is the definition of saturated?
this applies to any water store that has reached its maximum capacity
61
what is stemflow?
the portion of precipitation intercepted by the canopy that reaches the ground by flowing down stems, stalks or tree bole
62
what is a storm and rainfall event?
an individual storm is defined as a rainfall period seperated by dry intervals of at least 24 hours, and an individual rainfall event is defined as a rainfall period seperated by dry intervals of at least 4 hours
63
what is throughfall?
the portion of precipitation that reaches the ground or directly through gaps in the vegetation canopy and drips from leaves, twigs and stems.
64
what is throughflow?
the movement of water down-slope through the subsoil under the influence of gravity. it is particularly effective when underlying permeable rock prevents further downward movement
65
what is transpiration?
the loss of water from vegetation through pores on their surfaces
66
what is the water balance?
the balance between inputs and ouputs in a drainage basin
67
what does the soil water budget describe?
the soil water budget describes the changes in the soil water store during the course of a year
68
what is the key influence on the soil water store?
the key influence on the soil water store is the relationship between precipitation and evapotranspiration
69
wet seasons:
-precipitation exceeds evapotranspiration
-water surplus
-ground stores fill with water
-more surface runoff
-higher discharge
-river levels rises
70
drier seasons:
-evapotranspiration exceeds precipitations
-ground store and depletion
-some flows into the river channel but is not replaced by precipitation
71
what is discharge?
the amount of water passing a point over a given length of time. this is normally measured in cumecs or cubic meters per second
72
what is a strom hydrograph?
a graph of river discharge loading up to and following a stormar rainfall event
73
what is peak discharge?
highest flow rate in the river channel
74
what is the lag time?
the time between peak rainfall and peak discharge
75
what is falling limb?
river flow decreasing
76
what is bankfall discharge?
point at which a river will over flow (flood)
77
what is storm flow?
additional water in river from an overland flow + through flow
78
what is baseflow/groundwater flow?
amount of water that would be in a river without addition of storm water
79
what does a high peak discharge look like on a strom hydrograph?
steep rising + falling limb short lag time
80
what does lower peak discharge look like?
gentler rising + falling limb longer lag time
81
what is the drainage basin shape?
more circular in shape lead to more flashy hydrographs than those that are long and thin beacus each point in the drainage basin is roughly equidistant from themeasuring point
82
what is drainage basin relief?
-drainage basins with steep sides tend to have flashier hydrographs than gentley sloped river basins
-because water flows more quickly on steep slopes
83
drainage density:
basins that have a high drainage density have flashy hydrographs, all the water arrives at the measuirng station at the same time
84
antercedent rainfall:
if a drainage basin is already saturated the overland flow increases because inflitration capacity has been reached resulting in a flashy hydrograph
85
how do soil/rock type affect drainage basins?
drianage basins underlain by sandstones have subdued hydrograph because water soaks into the sandsound
86
how does vegetation affect drainage basins?
thick vegetation covering in drainage basins will subdue the hydrograph because vegetation intercepts precipitation
87
drought definiton?
a period of below average precipitation in a given region, resulting in prolonged shortages in water supply, whether atmospheric surface water or groundwater
88
the water cycle before deforestation:
much of the precipitation is returned to the atmosphere by evapotranspiration. overlandflow is minimal, most of the water that reaches the forest floor infiltrates into the soil & travels slowly to the river
89
the water cycle after localised deforestation?
evapotranspiration is lower because the replacement vegetation has smaller leaves,roots & is less dense. overland flow and throughflow occur because of lack of vegetation, increased discharge and flashiness
90
soil drainage:
soil drainage is practised in areas in order to reduce the amount of water near the surface as much too much water can cause damage to crops. this is because too much water in the soil restricts the oxygen avaliable to crops and reduces yeilds
91
what is the aim of soil drainage?
to reduce the amount of surface water/soil water and imptove agricultural potential of waterlogged land
92
what are the advantages of soil drainage?
-the build up of an improved soil structure, making it more friable and easier to work
-improved aration
-heavy machinery can work on land without danger of compaction
-increased aearation
-large numbers of animals can be allowed to graze the land without compacting the soil
93
what are the negative effects of soil drainage?
-discharge of rivers becomes more flashy
-peak discharges increases
-flooding more likely
-social and economic costs from flooding and subsequent damage
94
what are the disadvantages of soil drainage?
-the insertion of drains artificially increases the speed of throughflow in the soil, can increase the likelyhood of flooding
-the dry topsoil can be subject to wind eroison if not properly protected
-nitrate loss can lead to eutrophication
95
what is water abstraction?
the process of taking water from any source, either temporary or permanentely. this is mostly for agriculture and domestic water supplies
