The water cycle Flashcards
open system
Matter and energy can be transferred from the system across the boundary into the surrounding enviroment
Closed system
A transfer of energy both into and beyond the system boundary but not transfer of matter
is the water cycle open or closed system?
closed
what effect does positive feedback have on change?
increases the effect of change
what effect does negative feedback have on change?
decreases the effcet of chnage
What is the lithosphere?
The solid outer crust and upper mantle- land based water
Make up of the lithosphere:
surface water- river
ground water- deep water before impermeable rock
soil water
biological water- plant or animal matter
what is the hydrosphere?
Discontinuous layer of water near the earths surface
make up of the hydrosphere:
liquid and frozen surface water, groundwater and atmospheric water vapour.
Rivers-Lakes-Oceans
what is the atmosphere?
layers of gases surrounding the planet
make up of the atmosphere:
In terms of water
water storage in the clouds,clean air, microscopic particles or water vapour
process of relief rainfall
1- warm air rises over MOUNTAINS
2-air cools and condenses=clouds
3- air descends and warms
4-drier conditions known as rain shadow
process of converctional rainfall
1- sun heats the LAND and air above
2-warm air cools and condenses=clouds
3-rain
Frontal rainfall process
AIR MASSES
1- warm air forced to rise over cold air
2- condensation forms clouds
3-clouds bring heavy rain
what is the pressure like when air rises?
low
what conditions does rain need? ( pressure and air)
low pressure and air rising
what is the band of low pressure at the equator
ITCZ inter-tropical convergence zone
What is a drainage basin
The area of land which is drained by its river and its tributaries . The area of land is known as the catchment area
is a drainage basin an open or closed system?
open- water can be lost through evapotranspiration or runoff.
Equation for water balance
precipitation (p)= discharge (q) + evapotranspiration(e) +- changes in storage
what is water balance?
the balance between inputs and outputs in a drainage basin
what does a soil moisture graph show?
the relationship between precipitation and potential evapotranspiration over a year
soil recharge
precipitation> potential evapotranspiration
soil deficit
lack of water, plants will wilt or have adaptations
soil surplus
space in soil has been filled. too much water overland flow increases groundwater recharge - risk of flooding
soil utilisation
water used by plants
what does a storm hydrograph show
- river dischage over a period of time
- amount of precipiation over time
what is the purpose of a flood hydrograph
-see how drainage baisins respond to periods of rainfall
- predict flooding and put in place flood prevention methods
-compare how land use impacts drainage levels
factors affecting a storm hydrograph
- deforestation as they decrease interception speeding up surface run off
-impermeable pavements and housing developments
-flash flooding - steep land decrease rising limb
physical factors of a drainage baisin contributing to flash hydrograph
circular shape
steep sides
high drainage density
already saturated ground
geology
human factors affecting the shape of a flood hydrograph
flash hydrograph:
deforestation- redcues intrception
agriculture- can make ground impermeable
urbanistaion
Less steep hydrograph:
-afforestation
-soft enginering and flood managemnt schemes
give three ways in which land use affects the water cycle
water abstraction
soil drainage
deforestation
how much rainfall on average does the amazon recieve a year
1500-3000mm
what type of rainfall do they mainly get in the amazon?
convectional
wtaer cycle in Amamzon
no water defecit, high amounts of potential evapotranspirtaion,water suprlus and soil utilisation
impacts of deforestation on the water cycle
-less inetrception more sr
-evapotranspirtaion reduced meaning a reduction in cloud cover
-atmosphere becomes les humid meaning that transpiration will decrease
affect of pasture land on the water cycle
- moisture content in soil is 15% less
-temp in pasture land is 8 degreees hotter
-deeper roots in TR can pump more soil moisture to the surface
river exe key facts (4)
-flows for 60 miles
-length = 96km
-maximum elevation of 514m
-lowest elevation= 26m
how much of the river exe catchment is impermeable rock
84.4%
what is the land use around tghe river exe
- agricultural (67%)
-woodland(15%)
-moors and peat bogs (3%)
how much does runoff account for within the water balance within the river exe
65%
what recent developments have imoacted the water cycle
(2)
wimblewall resoivoir
peatland restoration exmoor
