:rain_cloud: Hydrosphere :rain_cloud: (Water cycle: (Surface runoff: When…
:rain_cloud: Hydrosphere :rain_cloud:
Water taken from natural sources can contain
contaminants (substances) that can be harmful:
Treat water before human consumption
Reducing water waste and pollution
We need to to minimise the polluting effect that our activity can have on the water system.
Practice crop rotation and reduce the use of chemical pesticides and fertilizers in agriculture.
Control the emission of toxic substances from industry, and reduce
thermal pollution by using cooling ponds and cooling towers.
Polluted water is unusable because its properties have been
changed by pollutants.
Biological pollution: water contains bacteria, virus or other
Physical pollution: water contains floating particles:
polluted thermally (it has been heated).
Chemical pollution: water contains traces of chemical
substancesheavy metals,fuel or pesticides.
Human water use can be:
Agriculture, industry and domestic activities use a lot of water. Depending on regional climate, this can lead to water shortage and drought if water reserves are not replenished by rain. That’s why it is important to try and save water as much as possible.
(water is taken from source and is not returned, or it is altered considerably)
Transport, hydroelectric energy and sport and leisure.
(water is not removed or is returned to source immediately).
Surface runoff: When liquid water is on the surface of the Earth it flows across the land. This water forms rivers that eventually return the water to the seas and oceans.
Infiltration: This occurs when water penetrates the surface of the Earth and becomes underground runoff.
Evaporation: This process involves the Sun heating surface water: the water evaporates, turning into water vapour, which then becomes part of the atmosphere
Condensation: Through this process the water vapour produced by evaporation and transpiration rises, cools down, and then turns into clouds.
Transpiration: This occurs when plants lose water due to evaporation caused by heat from the Sun. The water from this process also becomes part of the atmosphere.
Precipitation: After cloud has formed, water returns to the Earth’s surface as either liquid rain or solid snow and hail.
Movement: oceans: Surface water: we can found in:
Ground water: water is stored underground, under the surface on the Earth. Rainwater penetres in the Earth until it is stopped by a layer of impermeable.
Salt water (oceans and seas): sea is mixture of mineral salts, the most common component is sodium chloride (common salt).
Temperature depends on depth. Can be divided in:
oceans (surround continents)
seas: surrounded by lands and form of ocean.
All water on the planet (¾ on the planet surface):
we can divide the hydrosphere in layers:
Gas: water vapor produced:
Evaporation from surface water
Solid: below 0ºC, in it can exist snow, glaciers and ice.
Liquid: depending of the salt level:
Salt water: high content (seawater) (oceans and sea)
Brackish water: moderate salt (inland water)
Fresh water: very low salt content (inland water)
Importance of water:
Water is the most important external ecological agent that modificates the landscape (erosion and transport)
It regulates the body temperature.
is the main component for living things.
Properties of water: water molecules are composed by hydrogen (2 atoms) and oxygen. Water molecules are held together by bonds. The water molecules’s H2O. Density of water decreases below 4ºC, the water is density than the ice.
It's a part made of water (universal solvent).