The water cycle and water insecurity Flashcards
What is a closed system?
a system which transfers energy but not matter across its boundary to the surrounding environment
what is an open system
a system which transfers energy and matter across its boundary to the surrounding environment
what effect does size of water stores have on the hydrological cycle?
the larger the store the greater the potential of evaporation to occur which means that there is a greater chance of convectional rainfall
what factors effect the fluxes in the water cycle?
ground water saturation
evaporation rates (temperature)
interception
what three factors affect the water budget?
deforestation
abstraction
contamination
what is fossil water and where is it stored?
it is a fixed amount of water which has been contained in an undisturbed place for millennia, it’s usually stored underground such as aquifers
what are the three types of rainfall?
frontal
orographic
convectional
what is convectional rainfall?
isolation (heat and light energy) cause moisture to rise which then cools at altitudes and condenses to form precipitation, it usually occurs in hotter countries
what is frontal rainfall?
warm air rises over cooler air which pushed the warmer air up, causing it to condense at high altitudes to form rain clouds
what is orographic rainfall?
hot air roses over mountains and cools as it gains altitude until it condenses into rainfall
what are three physical factors that affect river discharge?
vegetation
topography
damn construction
what human factors affect the drainage basin?
deforestation
changing land use
over abstraction
how does climate change affect a drainage basin?
greater global temperatures means rising sea levels therefore increased rainfall and decreased salinity at the poles
what is residence times?
the average amount of time in which water is in a given location
what is the water budget?
a balance of inputs and outputs to a water basin
what is a river regime?
outlines the discharge of a basin
why is the water cycle a closed system
there are no external outputs or inputs
what natural things can affect the water budget?
permeability of rock/ soil
amount of vegetation
why might the type of soil affect river regimes?
the absorption of the soil
how fertile the soil is
if it can hold vegetation
what human reasons may affect the water budget?
urbanisation
over abstraction
state a characteristic of a water budget in a tropical environment?
flash flooding
high levels of interception
what does a hydrograph show?
a way of outlining the discharge of a river or water basin, in response to a rainfall event
why might the shape of a storm hydrograph vary in different areas
size of the water basin
lag time
who might find a hydrograph useful?
A farmer
