Y1) TERM 2- WATER AND CARBON CYCLES (E) Flashcards
What is a system model
They show us the components of an aspect of geography and how these components are linked through flows
What are the 3 types of systems (TOS)
isolated, closed and open
What is an isolated system (TOS)
Has no inputs or outputs and is rare in nature
what is a closed system (TOS)
Has inputs and outputs of energy, but not matter i.e. the water or carbon cycle
What is an open system (TOS)
Has inputs and outputs of both energy and matter i.e. the drainage basin system
Dynamic Equilibrium (DE+F)
when the inputs and outputs are balanced
Feedback (DE+F)
When an element of the system changes the equilibrium will be upset
what is negative feedback (DE+F)
it stabilises the system, allowing it to maintain its dynamic equilibrium.
what is positive feedback (DE+F)
it means that the system experiences further change, continuing the disruption to the equilibrium
examples of global stores of water
Oceans, lakes, aquifers, the cryosphere (glaciers and ice sheets)
Examples of local stores of water
Interception, vegetation storage, surface storage, soil moisture and groundwater storage
Examples of flows of water
Infiltration, throughflow, percolation, stem flow, base flow, channel flow and surface runoff
Examples of processes of water between stores
Precipitation, evaporation, transpiration, cryosphere exchanges and runoff
what percentage of freshwater is stored where (3 percentages)
68.8% cryosphere
30% groundwater
1.2% surface water
what percentage of surface water is in different places (7 percentages)
69% ground ice and permafrost
20% lakes
4% soil moisture
3% atmosphere
3% swamps and marshes
0.5% rivers
0.5% biosphere (living things)
what are the 3 types of precipitation (P)
Orographic, frontal and convectional
what is orographic precipitation (P)
when air masses rise over mountains causing it to condense and rain
what is frontal precipitation (P)
When two air masses meet at an area of low pressure creating rain
what is convectional precipitation (P)
Rainfall caused by water turning to water vapour due to solar radiation
What are the outputs from the drainage basins
Evaporation ,Transpiration and channel flow
What are the drainage basin water flows
interception ,infiltration ,direct runoff ,saturated overland flow ,throughflow ,percolation and groundwater flow
what factors effect the drainage basin
rock type ,soil type ,relief of the land ,vegetation cover and climate
what human factors effect the drainage basin
reservoirs ,over abstraction ,urbanisation and deforestation
what percentage of water is freshwater? and of that what is accessible for direct human use?
2.5% and of that 1%
2 examples of non renewable freshwater stores
Aquifers, glaciers/ ice caps
untouched ancient freshwater stores are referred to as
fossil water
untouched ancient freshwater stores are referred to as
fossil water
during spring and summer as the ice and soils thaw what is released into the atmosphere
biogenic gases
In tropical rainforests what percentage of precipitation is returned via evapotranspiration (TH)
50%
Rainforests are able to generate their own water cycle due to (TH)
convectional rainfall
how does convectional rainfall occur in a tropical rainforest (TH)
the forest floor is warm and so the air on the surface heats up and expands. This air rises and condenses forming rain clouds.
how does deforestation negatively impact the water cycle in a tropical rainforest (TH)
Deforestation reduces evapotranspiration which in turn reduces precipitation levels and water supply as less water is being put back into the cycle via plants. It instead will have to flow through streams and rivers, taking longer to cycle through.
what do hydrographs show (H)
Hydrographs show how river discharges changes over time at a particular point in a river. Increased runoff leads to a reduced lag time and greater discharge, producing a steep hydrograph because more water gets into the river channel quicker.
what is river discharge (H)
River discharge is the volume of water flowing in a river each second and is measured in cumecs (m3/s)
what is peak discharge
maximum discharge in the period of time
peak rainfall
maximum rainfall in the period of time
lag time
the interval between peak rainfall and discharge
rising limb
when the discharge is rising
falling limb
when the discharge is falling
4 physical factors effecting storm hydrographs
Rock and soil type
Size, shape and drainage density
Relief of land
Vegetation
example of permeable rock
example of impermeable rock
limestone -p
granite -ip
3 human factors effecting storm hydrographs
Land use ( agriculture )
Water management (dams, reservoirs)
Urbanisation ( tarmac, concrete tiles )
4 types of drought (D)
Meteorological
Agricultural
Hydrological
Soci-economic
what is Meteorological drought (D)
this type of drought presents a degree of dryness compared to what is considered to be normal precipitation levels for that area, climate and season.