The hydrosphere

• how do we identify changes in the hydrosphere-

  See how gases in the atmosphere affect the hydrosphere 

  Can see if floods are becoming more likely 

  Water is essential to human survival
• uses of water-

  Abstactive-manufacturing, washing machines, showers, can’t produce electricity without water cooling 

  Taken from the source to be used 

  Non-abstractive-  windsurfing, transport on the water-barges, generating energy, recreation, animal conservation 

  Water is not taken from the source
• Conflicts of water use-

  Some uses of water are not compatible…

  Wildlife conservation and energy production. 

  Wildlife conservation may conflict with recreation 

  Energy production may conflict with transport.
• solving water conflicts-

  Spatial zoning- only allow certain activities in certain places- not allowing water sports in areas of wildlife conservation

  Temporal use- allowing different activities at the same place but different times- recreation and energy production.
• how has deforestation affected the hydrolic cycle-

  Less transpiration

  Less interception by trees-more flooding soil less permeable

  Desertification- lack of moisture in the atmosphere

  Increased evaporation from surface of soil
• How has agriculture affected the hydrological cycle?-

  Less transpiration from a field of crops

  Soil evaporation increases surface runoff, crop irrigation increases evaporation rates, loss of soy abiotic reduces infiltration and reduces water retention

  Less earthworms to aerate the soil
• How has climate change affected the hydrological cycle?

  Some areas getting more precipitation and floods whereas some areas are experiencing drought. 

  Weather systems are staying still as there is a weaker pressure gradient
• water quality-

  Water quality is the measurement of the purity of a supply of water- 

  Physical-turbidity is a measure of how turbid or cloudy water is-water with a high level of suspended sediment is known as turbid

  Chemical criteria- various chemical techniques can be used to test for different chemicals e.g.- pH, pesticides, and heavy metal concentration

  Biological criteria- the detection of pathogens in the water e.g- the pressure of E.coli.
• resevoirs and aquifers

  Aquifers need to be porous and permeable

  Porous- holes

  Porosity-ability to store water

  percolate - clean(filter)

  Permeability- ability to allow water to travel through it. 

  Porous rocks- chalk,
• sources of fresh water-

  Surface stores-rivers and lakes

  Groundwater store- aquifers

  Sea water stores via desalination 

  Artificial reservoirs
• factors affecting the suitability of a water source-

  The amount of substances in it

  The amount of dissolved substances in the water

  The flow of the river-flowing water is cleaner-not stagnant -more oxygen and not as warm-less bacteria 

  The types of rocks water is passing over

  If iw is not going to endanger species 

  Is anyone dependent on water supply 

  Annual discharge amount

  Fluctuation in discharge rivers
• A reservoir is a large natural or artificial lake used as a source of water supply

  Where would you put a reservoir?

  In an area that needs more water

  An area with high rainfall

  Along a river that has suitable drinking water in it.

  Somewhere with a lot of space-flat and wide 

  Impermeable rock underneath so water doesn’t drain away

  Far from human  environment- reduce pollution- less likely to cause damage if it breaks

  Gravel pits form mined areas

  Large catchment area. 

  typography - a valley with a large volume and small surface area
• water management-

  Increase supply(abstraction)

  Increase availability  by reducing pollution of potential water sources

  Reduce demand(water conservation)
• • An aquifer is a rock that can store water
  • Aquifers are permeable (they allow water to travel through them) e.g. Sandstone
  • Aquifers may be porous (they have tiny holes within them in which water can be stored) e.g. chalk
• surface storage reservoirs

  Advantages-

  Can be used to produce renewable energy via hydroelectric plant

  Can store large amounts of water

  Disadvantages- Causes a lot of land to be lost

  Changes the microclimate of the area

  Causes erosion downstream

  Not suitable for areas where precipitation rates are low and evapotranspiration rates are high

  Emit greenhouse gases
• aquifer storage and recharge

  Advantages- Water is purified by percolating through the aquifer

  Is relatively cheap

  disadvantages-Some aquifers are confined, so don’t have a recharge zone

  Taking too much water out causes wetlands and rivers to dry up and subsidence to occur
• desalinisation plants-

  advantages-Sea water is in almost endless supply

  Disadvantages- Very expensive to run as they need high energy inputs

  High energy usage means production of greenhouse gases

  Need a coastal location

  Loss of coastal habitat
• estuary barrages

  advantages-Provides a large volume of trapped fresh water

  Can be used to generate electricity when combined with a tidal power station

  Disadvantages- Causes flooding of estuary mudflats and so loss of habitat

  Expensive to build

  Hinders boat traffic and migration of aquatic animals

  Needs an estuary location
• inter-basin transfer

  Moves water from an area of excess to an area of deficit

  disadvantages - Changes the water quality of the river the water is transferred to, which can affect the ecosystem

  Can introduce alien species from one catchment to another

  Needs a catchment with an excess of water near to one with a deficit
• catchment management

  Advantages- sustainable methods 

  disadvantages - can be difficult to change land-use patterns already in place

  Can only influence future land use changes