Water and Carbon cycle Flashcards
why is the water cycle a closed system?
because it powered by the sun and functions without human interference
what percentage of earth is covered by water?
72%
what is atmospheric water?
water found in the atmosphere; mainly water vapour with some liquid water and ice crystals
what is cryospheric water?
water locked up on the Earths surface as ice
what is oceanic water?
water contained in the earths oceans and seas but not including inland seas
what is terrestial water?
this consists of groundwater , soil, moisture, lakes, wetlands and rivers
what is the average PH of oceans and what has happened to it?
8.14 and it has fallen from 8.25 due to increased atmospheric carbon
define an ice cap.
thick layers of ice on land that are smaller than 50,00km^2
define an ice sheet.
mass of glacial land ice that is more than 50,00km^2
define a glacier.
they are thick masses of ice found between deep valleys or in upland hollows.
define permafrost.
land that is at or below 0°C for at least 2 consecutive years.
what happens if permafrost melts?
it releases methane and co2.
what is a river and its function?
a stream of water within a defined channel they act as a store/transfer of water. They transfer water from the ground, soils and atmosphere to a store which could be oceans, lakes or wetlands
what is a lake?
a collection of fresh water found in hollows on the land surface.
what is the difference between a lake and a pond?
a lake is larger than 2 hectares in area whereas a pond is smaller than 2 hectares in area
what is a wetland?
an area where water covers the soil, or is present either at or near the surface of the soil all year/periods during the year
why are wetlands important?
-water saturation determines how the soil develops and they types of plant/animal living in/ on the soil
-supports aquatic and terrestrial species
where is biological water stored?
in biomass such as trees and plants
what is the most common type of atmospheric water?
a gas; water vapour which is colourless, odourless and clear.
why is water vapour important?
it reflects , absorbs and scatters incoming solar radiation which keeps the atmosphere at a temperature in which it can maintain life
when does evaporation occur?
when energy from solar radiation hits the surface of water or land and causes liquid water to change state from liquid to a gas.
what does the rate of evaporation depend on?
-temperature of the air
-the amount of solar energy
-humidity of the air
-availability of water
what is condensation?
Condensation is the process where water vapor becomes liquid. It is the reverse of evaporation
what is hoar frost?
direct condensation of water vapour to ice at temperatures below freezing
what is a glacial period?
where large volumes of ice on land meant that sea level was approximately 120 m lower than present (water was frozen and there was a reduction in thermal expansion)
what is a interglacial period?
global ablation (melting) exceeded accumulation
and the hydrological cycle returned
which factors have driven a change in the magnitude of major stores of water?
evaporation
condensation
cyrospheric processes(accumulation/ablation)
what is a drainage basin?
an area of land drained by a river and its tributaries
what does the watershed mark?
the edge of the drainage basin
what is throughfall in the hydrological cycle?
canopy-surface rainwater storage exceeds its capacity
what is stem flow in the hydrological cycle?
flowing down stems,stalks or tree boles
what is interception storage in the hydrological cycle?
precipitation that falls on the canopy
what is water table in the hydrological cycle?
boundary between saturated and unsaturated rock
what is river discharge in the hydrological cycle?
the amount of water flowing through a river channel
what is soil storage in the hydrological cycle?
the amount of water stored in soil
define precipitation.
rain,snow,sleet.,or hail that falls to the ground.
define condensation.
a process where water vapour changes to liquid water
define evaporation.
the process where liquid water changes to a gas.This requires energy provided by the sun and aided by wind
define transpiration.
the loss of water from vegetation through pores on their surfaces.
define thorughflow.
the movement of water downslope through thr subsoil under the influence of gravity
define snow melt.
surface run off produced by melting snow
define throughfall.
the portion of the precipitation that reaches the ground directly through gaps in the vegetation canopy and drips from leaves.occurs when the canopy-surface rainwater storage exceeds its storage capacity.
define groundwater flow.
the slow movement of water through underlying rocks
define river channel flow.
the path through which a river flows
define surface run off flow.
water flow horizontally across land surfaces when rainfall has exceeded infiltration capacity.
define percolation.
the downward movement of water within rock under the soil surface.Rates depend on the nature of the rock.
define interception storage.
precip that falls on the vegetation surfaces or human made cover and is temporarily stored on these surfaces
why is infiltration capacity important?
because it varies according to the soil type to soil type and preceding conditions such as the level of saturation
what are the water stores?
-groundwater aquifers
-fossil aquifers
-water on land
-water and plants
-water and plants-interception
how is water stored in groundwater aquifers?
-about 30% of all freshwater is stored in aquifers which is porous body of rock underground
how is water stored in fossil aquifers?
fossils in the deserts of Africa,middle east and Australia are called this.They were formed thousands of years ago when the climate in these regions were wetter
how is water stored on land?
snow accumulation in winter adds to the mass of glaciers or ice sheets and in summer ice calves(breaks away)
how is water stored in plants?
plants remove water from the soil and store it.They then lose the water back to the atmosphere via transpiration.The process is called evapotranspiration.
how is water stored in plants (interception)
when rain falls water gets intercepted by leaves and branches and stored
what are the factors that affect the water cycle at a local scale?
-urbanisation
-deforestation
-farming-ditches drain the land and encourages water to flow quickly to rivers
-seasonal changes and storms
formula for river discharge.
cross section area x velocity
formula for velocity.
distance/time
what is a river regime?
the variability of a rivers discharge throughout the course of a year in response to precipitation, temperature, evapotranspiration, and drainage basin characteristics
what is discharge?
the volume of water flowing through a river channel measured at any given point given in cubic metres per second.
what is peak flow on a flood hydrograph?
the point where river discharge is t its greatest.
what is base flow on a flood hydrograph?
the amount of water in a river flowing past a particular point
what is bankfull on a flood hydrograph?
the maximum discharge that a river channel is capable of carrying without flooding
what is lag time on a flood hydrograph?
the time difference between peak rainfall and peak discharge
human factors that affect discharge.
-urbanisation
-deforestation
-agriculture
-flood engineering e.g. channel widening
summarise water abstraction in London.
- peak in the 1960s and groundwater levels below central London had dropped 88m below sea level.
-20th century chalk basal sand aquifer in London was exploited due to industrialisation
-in West London groundwater levels are increasing due to limited abstraction–>limited abstraction poses a threat to the London Basin
summarise water abstraction in southern Engalnd.
summarise water abstraction in Europe
-10% of Europes total freshwater source is being abstracted anually
-water being abstracted more than its being replenished by rain
summarise deforestation.
e.g. amazon
-evapotranspiration decreases
-overland flow increases
deforestation can lead to: climate change, desertification, soil erosion
summarise soil drainage.
e.g. East midlands
-drainage that removes excess water through tubes called tiles
-water is removed when water table>tiles
-increases infiltration
water flow processes
Throughflow
Inflitration
Percolation
Stemflow
Surface run off
Groundwater flow
water stores in a drainage basin
Groundwater
Rivers/Lakes
Interception
Soil
physical factors that affect discharge
-amount of precipitation
-relief(steep)
-soil type
-saturation
-drainage density(amount of rivers in an area)
draw a flood hydrograph
