ORANGE

• size of stores in order

  Hydrosphere -97%

  Lithosphere + cryosphere - 1.7%

  Atmosphere - 0.001%
• only 0.9% of the worlds freshwater is accessible to humans
• 2% of freshwater is locked away in the cryosphere or ground water
• 69% of the worlds freshwater is the cryosphere
• 30% worlds fresh water stored underground
• annual fluxes between atmosphere, ocean and land can vary temporally and spatially
• factors that influence fluxes

  climate (which impacts the temperature)

  location - ITCZ

  season
• cryosphere losses are non-renewable because of the enhanced green house effect - 75% glaciers are retreating - +ve feedback cycle
• fossil water is non-renewable because it is ancient water stored underground that cannot easily be replenished
• residence time tells us how long the water will stay in a reservoir
• the residence time varies spatially and temporally and often depends on the reservoir
• stores and transfers vary in a spatial and temporal sense
• water stays in the atmosphere for around 9 days v water in the cryosphere where it stays for hundreds of years
• factors impacted residence time

  climate

  type of store - location
• orographic rainfall

  solar insolation - evaporation of relatively warm water - rises cools and condenses - forms clouds - clouds are pushed by prevailing winds - clouds meet an obstacle e.g., mountain - cloud is forced to rises through a process called orographic uplift - rains over the windward side of the mountain - as the cloud passes over the leeward side - there is high pressure - prevents rain - leeward is sheltered and dry - Manc v Leeds
• Frontal rainfall

  • Relatively warmer equatorial air meets a colder mass of air - they are carrying moisture
  • Meets at a 'front' - where Hadley cell and Ferrell cell meet
  • Relatively warmer air rises over the colder air mass
  • as warm air rises, cools and condenses
  • Rain
  • Forms strata cloud, cumulus cloud and cirrus cloud
• Convectional rainfall

  • driven by heat
  • equatorial region has the most solar insolation
  • air can hold lots of moisture
  • ground heats the air above it
  • heat drives evaporation
  • as the air rises it cools and condenses
  • forms cumulonimbus clouds
  • heavy tropical rain
• inputs add water to the open system
• above land flows

  • direct run off
  • saturated overland flow
  • interception
  • throughfall
  • channel flow
• direct run off

  • rains - too much rain - soil reaches field capacity quickly - limited infiltration - water runs off the surface into rivers
  • rains - steep relief - the water is travelling at high velocity - not enough time to infiltrate - direct run off
• channel flow

  • out put of the basin
  • water flows between channels or rills into a different basin
  • flows in a defined stream pattern
• saturated overland flow

  • rain - soil reaches field capacity - reduced infiltration as that is a slow flow - water flows overland as takes the easiest route
• interception

  • rain is intercepted via vegetation
  • slows the water down
  • influences the type of flow that dominates
• interception reduces the amount of water that reaches the ground - reduces the amount available for overland flow - reduces flooding and increases evapoT
• Below ground flows

  • percolation
  • groundwater flow
  • through flow
  • infiltration
• percolation

  • water moves from soil into the bedrock
  • water is pulled down by gravity
  • the rate of this is determined by the soil and rock type
• throughflow

  • lateral flow
  • slow
  • moves through hydrostatic pressure
  • upper soil layer
  • moves along soil lines of seepage of percaline
• ground water flow

  • water percolated into bed rock
  • slowest type of flow
  • moves sideways through hydrostatic pressure
  • base flow - feeds rivers and can act as an output
  • can recharge aquifers if there is an excess of water
• infiltration

  • water moves from surface to soil
  • depends on the type of soil
• outputs

  • evaporation
  • transpiration
  • channel flow
• physical factors impacting open drainage basin systems

  • climate
  • soil
  • geology
  • vegetation
  • relief
• climate impacting inputs, flows and outputs

  • tropical climate - convectional rainfall - high levels of potential evapoT
  • cold - precipitation falls as snow - water is not mobile - impacts speed of flow - less potential evapoT as too cold - can lead to polar deserts
  • impacts the amount of vegetation
  • outputs: extent of evapoT
  • inputs: type of rainfall
  • flows: speed of flows
• climate is the most important physical factor because it is dynamic and has future uncertainties attached to it
• relief impacts on flows, inputs, and outputs

  • aspect - North facing - greater soil moisture retention - not as much sun - less solar insolation and lower levels of evapoT - less rain
  • Gradient - steep - high velocity - too fast to infiltrate - direct run off - could cause flooding
  • Impacts type of rainfall - orographic
  • continentality - Gobi Desert
• soil impact on inputs, outputs and flows

  • infiltration: composition of the soil - clay soils have large field capacity - porous so can hold water in pore spaces vs sandy soils have lots of openings and connected pores that allow the water to seep through
  • evapoT: if does not allow for infiltration can lead to more evapoT as the water is exposed to solar insolation
  • pores and openings for the water to move through are different in all soils
  • Climate impact: if the soil is frozen means that cannot infiltrate - direct surface runoff
• geology impacts inputs, outputs and flows

  • percolation: depends on how permeable the rock is
  • permeability depends on pores and bedding plains
  • if the rock is porous and the pores are connected = permeable
  • if the rock is pervious = permeable as water can move via bedding plains - these are horizontal weaknesses
  • percolation impacts type of flow: if percolated then see through flow and groundwater flow
• vegetation impacts inputs, flows and outputs

  • interception
  • evapoT
  • through fall
  • drip flow
  • stem flow
• there is a lot of clay in the SE of the UK
• Water budgets show the annual balance between inputs of outputs into the open system
• the balance of water budgets can impact soil water budgets