water cycle Flashcards
what is a closed system
where energy can move but matter cant
what is the water cycle
the continuous movement of water in a closed system around the hydrosphere, cryosphere, atmosphere, biosphere and lithosphere
what s the atmosphere
the body of gas between the ground and sky
whats the cryosphere
the frozen bodies of water across the globe
what is the hydrosphere
the oceans and rivers and lakes
what is the biosphere
the water in all organisms across the globe
what is the lithosphere
the ground consisiting of the rigid crust and upper mantle which traps water
what is the water budget
the total net flow of water in the globe, a surplus is when water inputs are higher than outputs and a deficit is when outputs are higher
what is a river regime
the annual flow of discharge from a river
what is a flood hydrograph
a graph showing the discharge of a river following a rain event
what factors affect the discharge of a river
-ground type/ rock types
-shape of the land (topography)
-anticendent conditions (how saturated is the land after a previous event)
-vegetation
-level of precipitation
-size of drainage basin
-deforestation
-afforestation
-urbanisation
what is the lag time
the time taken for rain to reach a river, difference between peak rainfall and peak discharge.
what is a flashy hydrograph
where the line is steep as rain reaches the river faster, there is a shorter lag time
what is orographic rainfall
where wamr air forces its way up a steep hill and condenses once it reaches the top and forms clouds. rain falls over the other side of the mountain
what is frontal rainfall
where an area of warm air meets cold air, the warm air rises above as it is less dense and condensates and becomes clouds. then rains
what is convectional rainfall
where hot temps heat up surfaces and create warm air which rises up and then cools down to form clouds.
where is the most water stored
in the hydosphere
what is evapotranspiration
the combination of evaporation and transpiration
what is percolation
the downfall movement of water through rocks and becoems groudnwater
what is throughflow
where water moves down to a river through the surface of the ground
what is infiltration
water moving into the ground
what are the inputs of water into the water system
precipitation
what is an aquifer
a deep ungreground store of water in rocks
what is surface runoff
water running down into the river overground
what is throughfall stemflow
water moving from plants to the ground
what is the water balance
the total level of water able to be held in soil
what is porosity
the proportion of the volume of the material that consist of void spaces, for example how many holes there are in a rock for water to be stored in
what is permeability
the volume of water able to flow through a surface
what is the dewpoint
the temp where water turns into a liquid
why is water vapour important
it absorbs, reflctes and scatters incoming solar radiation
why is water vapour bad
it is a greenhouse gas which traps in heat
how will global temps affect the level of water vapour in the atmosphere
as temps rise there is more evaporation, this lead to more water vapour in the atmosphere and then the global temps heat even more
what determines infiltration
-level of vegetation
-topography
-degree of permeability
what is water abstraction
the removal of water from the water table in underground storages
who are gardit
general aquifer research development and investiation who aim to control the water table level
what will overabstraction lead to
a lowering of the water table
what will a high water table lead to
there will be less room for water storage underground so surface run off and throughflow of water will be high, leading to high risks of flooding
what do gardit do
they aim to control the water table level in london to ensure the city doesnt flood
what is the watertable
an underground boundary between the soil surface and the area where groundwater saturates spaces between sediments and cracks in rock.
what is the biotic pump theory
a theory that suggests that when rain falls over a forest, plants release 80% back into the atmosphere which will lead to more rainfall further into the forest and eventually will stimulate more growth of the forest.
what impact do humans have on the water cycle
-urbansiation
-afforestation and deforestation
-global warming
how large is the river chelmer catchment
190,000km2
what rates of discharge does it have across a year
0.15 cumecs to 30 cumecs
what has affected the river chelmer
-urbanisation of the area
-deforestation
-climate change
-abstraction
-agriculture
-population change
how does agriculture affect the river chelmer
lowered the water table by 1m as water was abstracted for farming purposes.
population change in chelmsford
from 160,000 to172,000
what % of urban surfaces have grown in chelmsford since 1970s
3% growth of urban surfaces
what is a drainage basin
an area of land drained by a river and its tributaries
