water and carbon cycle Flashcards
what are systems composed of?
- inputs (matter/energy added to system).
- outputs(matter/energy leaves system)
- stores (matter/energy builds up in a system)
- flows (matter/energy moves in system)
- boundaries (limits to the system)
what are open systems?
when system receive inputs and transfers outputs of energy or matter
what are closed systems?
energy inputs equal outputs
what is dynamic equilibrium?
inputs equal outputs despite changing conditions
what does positive feedback do?
takes away from dynamic equilibrium
what does negative feedback do?
brings back to dynamic equilibrium.
on a local scale are water and carbon cycles open or closed?
open
what system are the water and carbon cycle on a global scale?
closed
in a local drainage basin how may water get lost and gained?
- evapotranspiration/ runoff
- precipitation
what are the 3 types of rainfall?
convectional
relief
frontal
what is. convectional rainfall
warm air rise
condenses at high altitudes
falls as rain
what is relief rainfall?
warm air forced upward by barrier (mountain) causing it to condense. at higher altitudes and fall as rain
what is frontal rainfall?
warm air rises overcool air, condenses at higher altitudes and falls as rain
what is frontal rainfall?
warm air rises overcool air, condenses at higher altitudes and falls as rain
when does evapotranspiration occur?
when water is heated by the sun causing it to become a gas and rise into atmosphere.
when does transpiration occur?
in plants whiney respire through their leaves, releasing water they absorb through their roots, which then evaporates due to heating by the sun
stem flow as an output
all water that enters a drainage basin will either leave through the atmosphere, or through streams which drain the basin. may flowing tributaries.
what is infiltration?
process of water moving from above ground to soil
what is infiltration capacity?
how quickly infiltration occurs
infiltration as a flow?
grass crops/ tree roots create passages for water to flow into soil.
what is percolation?
water moves from ground or soil into porous rocks and rock fractures
what is the percolation rate dependant on?
fractures that may be present in the rock and permeability of rock
what is through flow?
water moves through soil and into streams and rivers
what is speed of flow dependant on?
type of soil soils with smaller pore
have a slower flow rate . Sandy soils drain quickly
larger pore spaces
surface run off as a flow?
water flows above ground as sheet flow or in rills
what is ground watre flow?
water moves through rocks
stemflow as a flow
- Flow of water that has been intercepted by plants or trees, down a stem, leaf, branch
or other part of a plant - Fast.
stores in the water cycle?
- soil water
- groundwater
- river channel
- interception(water intercepted by plants)
- surface storage
what is the water table?
upper level where pores and fractures in the ground become saturated
what is the water balance used for
to express the process of water storage and transfer in a drainage basin system
what is the formula for water balance?
precipitation=total runoff + evapotranspiration+/-(change in) storage
the water cycle is impacted on a local scale by? human factors
- deforestation (less interception by trees so surface run off increases)
- agriculture (pastoral farming, animals trample ground reducing infiltration)
- urbanisation (impermeable surfaces reduce infiltration but increase surface runoff reducing lag time)
the water cycle is impacted on a local; scale by? physical factors
-storm events (large rainfall saturates ground to its field capacity, no ,more infiltration, more surface run off )
-seasonal changes (spring - more vege more interception
summer-less rain more impermeable surfaces
autumn-less vege less intercep, more rainfall
winter-frozen ground impermeable, less run off due to snow )
what is the soil water budget?
annual balance between inputs and outputs in water cycle and impact on soil water availability
what is the soil water budget dependant on?
type, depth and permeability of the soil and bedrock
what is field capacity
max possible amount of storage of water in soil
seasonal variation of the soil water budget autumn?
greater input from precip than output from evapotranspiration
seasonal variation of the soil water budget winter?
evapotranspiration from plants/ trees reaches minimum precip continue to refill soil water stores
seasonal variation of the soil water budget spring?
potential evapotranspiration increase as temp increases and plants photosynthesis more
seasonal variation of the soil water budget summer ?
utilisation of soil water as evapotranspiration and rainfall minimum. output from evapotranspiration greater input from
precipitation so the soil water stores are depleting
what is the largest store of global water?
oceans (97%)
what percentage of stores are fresh water? of which? what % is ground water?
2.5% , 69% glaciers, ice caps and ice sheets and 30% ground water
surface water and other fresh water stores account t for % of global; stores
1%
what are other surface and freshwater stores?
permafrost, lakes, swamps,, marshes, rivers, living organisms
water can be stored in what 4 areas?
- hydrosphere- any
- lithosphere- crust and upper mantel
- cryosphere- any water frozen
- atmosphere- water vapor
what are aquifers?
underground water stores
how long can shallow underground aquifers store water for?
200 years
how long can deeper fossil aquifers hold water for?
10,000 yrs
how long can glaciers hold water for?
20-100 yrs
how long can lakes hold water for?
50-100 yrs
seasonal snow and rivers hold water for how long?
2-6 months
how long does soil water hold for?
1-2 months
what is the global atmospheric circulation model?
determines cloud formation and rainfall
what is ITZC
inter-tropical convergence zone
what is the low pressure Zone on the equator called?
ITZC
what is the zone partly responsible for?
monsoons due to heavy rainfall
why does this zone move?
sun position changes
what are the names of the cells that cause unstable whether in the UK?
FERREL AND HADLEY CELLS
what effect do droughts have on the water cycle over time?
cause major stores to be depleted. more common due to climate change
how often does ‘the El Nino effect’ occur? what does it cause?
2-7 yrs
warm temps
(increase due to climate change)
how often does ‘the El Nina effect’ occur? what does this cause?
2-7 yrs
cooler temps
what effect does the cyrospheric process have on the water cycle over time?
almost all of worlds glaciers are shrinking, sea level rise (if all melt rise sea levels by 60m)
what effect does water abstraction have on the water cycle?
reduces vol of water un surface stores
abstraction from aquifers as output greater than inputs= decline in global long term water stores
what is a flood hydrograph used to represent?
rainfall for the drainage basin of a river and the discharge of same river
what is discharge on flood hydrograph?
vol of water passing through cross section of river (made up of base flow and storm flow)
what does rising limb represent on flood hydrograph?
discharge increasing
what does falling limb represent on flood hydrograph?
discharge decreasing
what does lag time represent on flood hydrograph?
time between peak rainfall and peak discharge