Enquiry 1 what are the processes operating within the hydrological cycle from global to local scale Flashcards
water cycle
operates on a variety of scales where physical processes control the circulation of water between stores on land, oceans, the cryosphere and atmosphere
type of cycle
closed system with inputs (precip), outputs, stores and flows
driven by solar energy and gravitational potential energy
stage 1
EVAPORATION: water vapour from oceans is lifted and condensed in the atmosphere to form clouds
stage 2
MOISTURE: transported around the globe, some evaporates back into atmos and some percolate the ground to form groundwater
stage 3
Balance of water that remains on the surface is called RUNOFF and is emptied into lakes, rivers and streams which carry it back to the ocean
ocean store
water- 96.9%
residence time- 3,600yrs
Icecaps
water- 1.9%
residence time- 15,000yrs (size dependent)
groundwater
water- 1.1
residence time- up to 10,000 yrs
rivers/lakes
water-0.01
residence time- 2 weeks to 10yrs
blue water
water in rivers/lakes (visible)
green water
water in soil/vegetation (invisible)
deep-seated groundwater
not renewable Sahara desert fossil water result of the pluvial period not reachable
accessible stores
soil moisture
lost to other stores by evap/ transpiration/ groundwater flow
water for life support
2.5% of global water is freshwater
rivers have 0.007% so are a source of conflict/disputes
30% in groundwater/ some fossil water (slow turnover period)
drainage basin
an area of land drained by a river
interception
precip that does not reach the soil as it is intercepted by vegetation and forest floor
throughflow
flowing of water within the soil, moving towards the river
infiltration
water on the ground soaking into the soils and porous rock
percolation
movement of water through the soil or underlying porous rock, being stored as groundwater
outputs in a drainage basin
evapo runoff (all the water that enters a river channel and eventually flows out of the drainage basin)
evapotranspiration in a drainage basin system
the total output of water from the drainage basin directly into the atmos
stores in a drainage basin
interception storage surface water soil water groundwater channel storage
transfers in a drainage basin
stemflow
infiltration
overland flow
channel flow
watershed
boundary that separates one drainage basin from another, typically following a ridge or high land
drainage basin as an open system
it exchanges matter with its surroundings
human disruptions to the drainage basin
deforestation farming and irrigation dam construction pollution from industry urbanisation
physical factors affecting outputs (climate)
climate- (temp and precip patterns determine availability and vary according to latitude)
seasonality determines patterns
summer temp increases evap but plant growth increases transpiration
equatorial areas receive the most rainfall
physical factors affecting outputs (geology)
geology- determines underground storage according to permeability
physical factors affecting outputs (river systems)
flow increases downstream but climate creates variation in discharge and water loss
Water budgets
Show the annual balance between inputs (precipitation) and outputs(evapotranspiration) and their impact on soil water availability
Water budgets influenced by
Climate types
Temperate- mood temps and steady climate
Tropical-tropical wet/ monsoon/ wet and dry seasons
Polar-tundra and Ice caps. Tundra summers are short and in ice cap seasons temps are seldom above freezing
Storm hydrographs main features
Peak discharge- reached after peak rainfall
Rainfall input- discharge rise and rising limb
Storm input cease and river water decrease- recessional limb
Time interval- between peak rainfall and discharge= lag time
Discharge returns to normal (base flow)
Storm hydrographs shape factors
Shape- circular basin( shorter lag time and ‘flashy river’) Elongated basin (delayed and ‘flat river’)
Weather/climate- high temp (high evap) and steady rain (less infiltration) = flat river
Human activity- urbanisation(impermeable) = flashy river
Soil moisture budget
Soil moisture surplus
Soil water utilisation
Soil water deficit
Soil water recharge
Field capacity