THE LIQUID PART OF THE THE LIQUID PART OF THE EARTHEARTH

Noelia Vicente IbáñezNoelia Vicente Ibáñez

Unit SummaryUnit Summary

1.1. The HydrosphereThe Hydrosphere

2.2. The water cycleThe water cycle

3.3. The Earth’s freshwater reservesThe Earth’s freshwater reserves

4.4. The water we drinkThe water we drink

1. THE HYDROSPHERE 1. THE HYDROSPHERE

The water in the Earth’s The water in the Earth’s surface is called the surface is called the HYDROSPHERE.HYDROSPHERE.

• 97% of water is in the 97% of water is in the oceans (salt water)oceans (salt water)

• Most of the 3 % of Most of the 3 % of fresh water is stored fresh water is stored at the polar icecaps at the polar icecaps

• Only 0,01% is used for Only 0,01% is used for human consumptionhuman consumption

Water propertiesWater properties

• Water is a very good solventWater is a very good solvent

• Water has a high thermal capacityWater has a high thermal capacity

• Water reaches its maximum density in a Water reaches its maximum density in a liquid state at 4ºCliquid state at 4ºC

2. THE WATER CYCLE2. THE WATER CYCLE

The four processes of The four processes of the water cycle the water cycle are:are:

• EvaporationEvaporation

• TranspirationTranspiration

• CondensationCondensation

• PrecipitationPrecipitation

3. THE EARTH’S FRESHWATER 3. THE EARTH’S FRESHWATER RESERVESRESERVES

Freshwater can be found in the form Freshwater can be found in the form of:of:

• Rivers and torrentsRivers and torrents

• GlaciersGlaciers

• Lakes and poolsLakes and pools

• Groundwater Groundwater

Rivers and torrentsRivers and torrents

• 0,03% of all land 0,03% of all land waterwater

• River flow along a River flow along a riverbedriverbed

• Torrents are Torrents are seasonalseasonal

GlaciersGlaciers

• 79% of freshwater 79% of freshwater reservesreserves

• Types of glaciers:Types of glaciers:– Valley glaciers or Valley glaciers or

alpinealpine– Continental glaciers Continental glaciers

or polar icecapsor polar icecaps

Lakes and poolsLakes and pools

• 0,07 % of fresh water0,07 % of fresh water

• Lake bigger than poolLake bigger than pool

GroundwaterGroundwater

• 20 % of freshwater20 % of freshwater

4. THE WATER WE DRINK4. THE WATER WE DRINK

Our freshwater Our freshwater comes from lakes, comes from lakes, rivers and rivers and groundwater.groundwater.

• Reservoirs Reservoirs Rivers Rivers

• Wells Wells GroundwaterGroundwater

The quality of waterThe quality of water

Purification process: eliminates impurities and Purification process: eliminates impurities and pathogenic microorganismspathogenic microorganisms

Wastwater treatment: treating urban sewage in Wastwater treatment: treating urban sewage in wastwater – treatment plants to use againwastwater – treatment plants to use again

The problem of The problem of contaminationcontamination

Water can be polluted Water can be polluted by:by:

• Sewage (blackwater or Sewage (blackwater or faecal water)faecal water)

• Agricultural activityAgricultural activity

• Industrial wasteIndustrial waste