EQ1 Flashcards
what is the water reserve with the shortest residence time and what is that residence time?
biospheric water-1 week
what is the water reserve with the longest residence time and what is that residence time?
groundwater-up to 10,000 years
what are the top 3 stores of water in terms of volume?
ocean
ice
groundwater
what volume of water does the ocean hold?
1.3 trillion km3
what volume of water does ice hold?
26 million km3
what volume of water does groundwater hold?
15.3 million km3
what percent of global water is oceans?
97.5
what percent of global water is freshwater?
2.5
what freshwater water source is the largest?
glaciers
what percent of freshwater is surface and atmospheric water?
0.4
what 2 processes drive the hydrological cycle?
solar energy
GPE
what is another name for water balance?
water budget
what is water balance?
the balance between precipitation, evaporation and runoff. it’s a tool to asses the current status and trends in water availability of an area over a specific amount of time.
what is the water balance equation?
P=Q+E +ΔS
what does P mean in the water balance equation?
precipitation
what does Q mean in the water balance equation?
runoff/river discharge
what does E mean in the water balance equation?
evaporation
what does S mean in the water balance equation?
storage in soil, aquifers, or reservoirs
how are rainforests self-sustaining in terms of water?
high rates of interception and evapotranspiration cause high humidity +heavy local convectional rainfall-rainwater recycled within system
what factors affect river regimes?
size of river+where measurements are taken in basin
amount, pattern and intensity of precipitation
temperature
geology+overlying soils-permeability+porosity
amount+type of vegetation cover (wetlands can hold water+release it slowly into system)
human activities like dam building
what is a river regime?
the annual variation in discharge or flow of a river at a particular point or gauging station usually measured in cumecs.
what are the social impacts of Karachi’s water crisis?
- water pumps running 2h a fortnight in middle of night
- criminal gangs siphoning off water + selling it for inflated amounts
- diseases from dirty water
- gender inequality-woman spends her whole day looking for water/conserving it
what are the economic impacts of Karachi’s water crisis?
agricultural loss
people spending loads of their money on water-1/2 their wages
what are the environmental impacts of Karachi’s water crisis?
agricultural loss
rivers, lakes and wells dry up
saltwater encroachment- water in wells becoming salty
lack of vegetation-change of ecosystem-desertification
fact about humans affecting amazonia?
tocatins river showed 25% increase in river discharge 1960-1997, coincident w increased deforestation.
