geog water Flashcards
why is the earth a closed hydrological system
because negligible amounts of water can enter or leave the atmosphere and the water is recyled.
what is infiltration
the transition of water going from above ground into the soil
what is percolation
the downwards movement of water through soils and into rocks due to gravity
what is evapotranspiration
the combination of water evaporating from surfaces of vegetation and through the transipration of plants
what is throughfall
precipitation falling through vegetation and straight onto the ground
what is stemflow
precipitation falling through vegetation and travelling down branches/stems to the ground
what is interception
precipitation being caught by vegetation before hitting the ground
what are the stores of water
clouds, oceans, lakes, curface storage, channel flow
what are the flows of water
throughfall, stem flow, interception, percolation, infiltraton, evapotranspiration
what 2 things power the global hydrological cycle
solar energy and gravity
what is the cryosphere
all the frozen parts of the earth, that includes ice caps, glacies, permafrost e.c.t this helps to maintain the earths climate
what is residency times
the average amount of time a water molecule will stay in a store
name the non-renewable water supplies
cryosphere, fossil aquifers
what factors impact a drainage basin
climate, soils, geology, human, vegetation, topography
what is orographic rainfall
precipitation that occurs when a cloud is forced over a geographical feature causing the clouds to cool and condense into rain
what is frontal rainfall
when warmer air masses raise above denser, cooler air masses and the warmer air cools down and condenses into water vapour that creates rain
whats convectional rainfall
the sun heating the ground which causes the air above to rise and cool, which creates clouds and rain
what is a complex river regime
can have multiple high and low flow seasons and various different climates
what is a simple river regime
only has one high and low flow season and a reliable climate
what is a flashy hydrograph
high peak discharge
long lag time
steep rising limb
what is a flat hydrograph
low peak discharge
short lag time
gentle rising limb
what factors affect a flood hydrography
vegetation, humans, drainage basin, geology, intensity of rainfall event, topography
what is a blocking high pressure system
when a high pressure system remains stationary/moves very slowly and doesn’t produce any precipitation. this is associated with hot weather and little cloud coverage.
where is the ITCZ located
it is a band across the equator that forms due to the Haddely cell. the low pressure systems cause air to rise and then cool and condense into clouds and precipitation.
what is the ENSO cycle
el nino = a climate pattern that happens every 2-7 years thats caused due to the warming of the central eastern pacific ocean
la nina = a climate pattern thats part of the el nino cycle and leads to the cooling of the central and eastern pacific ocean
what is the indian ocean dipole
a climate phenomenon that describes the difference in sea-surface temperaturs in the western and eastern indian ocean.
+ = warmer in west and cooler in east
neutral = average temperatures across the ocean
- = cooler temps in the weat and warmer in the east
how will climate change impact the water cycle
increased evapotranspiration means more water cirulating in the atmosphere
increased frequency of ENSO cycle
precipitation events vary more
winter looding 4.5X more likely in 2100 and summer droughts are 3X more likely in 2100
higher water vapour means more precipitation events
warmer temps lead to dryer land
what is water stress
renewable water sources are between 1000-1700m3 per capita
serious restricitions on water use, competetion for water, conflict, harvest failure
what is water scarcity
renewable water sources are between 500-1000m3 per capita
tensions, conflict, over-abstraction, insufficient flows
what is absolute water scarcity
renewable water sources are below 500m3 per capita
widespread resitrictions and rationings of water
what are renewable water sources
long-term annual total of internal and external water sources
internal sources are discharge of rivers and recharge of aquifers that’s generated by precipitation
external sources are generated outside a country and include inflows from upstream countries.
human causes of water stress
population growth
industrialisation and urbanisation
changes in living standards and food consumption
political conflicts
over-abstraction
the price of water
physical causes of water stress
causes of droughts
changes in precipitation patterns
ENSO cycles
warmer weather increases growth of bacteria
