the water cycle Flashcards
what human factors can affect hydrograph shape?
- urbanisation
- agriculture/farmland
- channelisation
- dams/ hard engineering
- deforestation
- aforestation
how can agriculture/farming affect hydrograph shape?
- farm machinery can compact soil so its impermeable resulting in a flash hydrograph
- after harvest = flash
- before harvest = flat
what physical factors can affect hydrograph shape?
- number of tributaries
- relief
- vegetation cover
- geology
- rainfall amount
- size + shape of catchment area
when may there be a flash hydrograph?
- thunderstorms
- urban areas
when may there be a flat hydrograph?
- forest areas
- chalk area
how is rain formed ?
- air rises
- air cools
- condensation
- rain falls
when will there be relief rain?
when a mountain causes the air to rise, resulting in rainfall
when will there be frontal rain?
when warm air meets cold dense air
when will there be convectional rain?
when hot temperatures cause the air to rise
why is the global hydrological cycle a closed system?
the amount of water within the system stays the same, it is transferred between different stores
what are examples of stores in the drainage basin system?
- groundwater
- vegetation
- soil
what are examples of outputs in the drainage basin system?
- river flow into the sea
- evaporation
- evapotranspiration
what is an example of inputs into the drainage basin system?
- precipitation
what are examples of flows in the drainage basin system?
- infiltration
- percolation
- surface run-off
- through flow
- groundwater flow
define afforestation
planting trees on land that has never had a forest
define agricultural drought
a rainfall deficiency from meteorological drought leading to deficiency in soil moisture, affecting plant growth and yields.
define aquifers
a permeable or porous rock which stores water
define base flow
the normal day-to-day discharge of a river
define blue water
water stored in rivers, streams, lakes and groundwater in liquid form
define catchment area
the area of land drained by a river and its tributaries
- drainage basin
Define closed system
A sequence of linked processes with a transfer of energy, but not matter, between the parts of the system
Define condensation.
The change from a gas to a liquid?
Define cryosphere
areas of the earth where water was frozen into snow ice.
Define deforestation.
The cutting down removal of all or most trees in a forested area.
define desalination.
The process of converting salt water to fresh water suitable for human consumption and industry.
Define desertification.
Land degradation in arid, semi arid and dry, subhumid areas resulting from various factors including climatic variations and human activities.
Define dew point.
The temperature at which Dew forms.
Define drought.
An extended period of deficient rainfall relative to the statistical outrage for a region measured over a very long period of time.
Define economic waters scarcity.
when water resources are available, but there is insufficient human institutional and financial capital to access the water in order to meet demand.
Define Enso cycle.
a naturally occurring phenomenon, but involved the movement of the mass of very warm water in the Equatorial Pacific due to changes in the surface trade winds, atmospheric circulation and ocean currents. There are two phases, al Nino and La Nina.
Define eutrophication.
Excessive richness of nutrients in a lake or other body of water frequently. due to runoff from farming land, which causes a dense growth of plant life and death of animal life from a lack of oxygen.
Define evaporation.
The change in the state of water from a liquid to a gas.
Define Evapotranspiration.
The combined effect of evaporation and transpiration.
Define falling limb.
The pot of a storm hydrograph in which the discharge starts to decrease and returns base flow.
Define famine drought.
A humanitarian crisis in which the widespread failure of agricultural systems needs to food shortages and famines with several social, economic and environmental impacts.
Define flash flood.
A flood with an exceptionally short lag time, often minutes or hours.
Define fossil water.
Ancient deep groundwater from former wetter periods.
Define green water.
Water stored in the soil and vegetation.
Define groundwater flow.
The slow transfer of percolated water underground through porous rock.
Define hard engineering
The use of man-made artificial structures to manage flooding or water supply.