Presentation on theme: "Fresh & Salt Water Systems Earth is called the ‘blue planet” because 74% of the surface is covered by water. The hydrosphere is the area of Earth and its."— Presentation transcript:
Fresh & Salt Water Systems Earth is called the ‘blue planet” because 74% of the surface is covered by water. The hydrosphere is the area of Earth and its atmosphere where water (and life) is present.
Water in the World 97% is salty… only 3% is fresh… and most of that is frozen!
In reality only 0.3% of the Earth’s water is useable by humans! What do you use water for?
In reality only 0.3% of the Earth’s water is useable by humans!
Distribution of Water 97% is salty… only 3% is fresh… and most of that is frozen!
Who has the water? four countries hold almost half of the Earth ’ s renewable supply of freshwater: * Brazil 18%* Canada 9% * China 9%* United States 8% most of our water is used to feed us! –73% Agricultural Use –22% Industrial Use –5% Domestic Use (including drinking)
Water in Canada The Pacific watershed lies west of the Continental Divide in the Canadian Rockies. Canada has 5 major watersheds (drainage basins)
Water in Alberta Alberta has just over 2% of Canada’s water supply. 80% of our water is in the north… 80% of our water use is in the south. Beaver River Basin North Saskatchewan River Basin South Saskatchewan River Basin Milk River Basin To Arctic To Hudson’s Bay Hay River Basin Peace/Slave River Basin Athabasca River Basin To Gulf of Mexico
In Alberta… 97.5 of our drinking water comes from surface sources water is often stored in reservoirs for future use
Properties of Water water (H 2 O) is made up of hydrogen and oxygen water molecules like to stick to other water molecules → cohesion water also likes to stick to other things it comes into contact with → adhesion most organisms are made up of 60 – 99% water –humans are about 65% water –apples about 84% –watermelon about 98%
2 billion people do not have access to sanitation systems 1 billion people do not have access to safe drinking water 3 million people die every year from lack of clean water for drinking, cleaning and irrigation ¼ of the world population gets its water from the aquifers located under ground … but groundwater supplies takes a long time to replenish! Did you know?
Would you drink this water? life on Earth depends on the quality of water contained in the hydrosphere freshwater is not just H 2 O → it contains: –dissolved compounds such as salts, phosphorous and other minerals –dissolved gases –suspended particles (of earth) –living organisms adapted to local environments saltwater also contains salt –3.5% more salinity than freshwater
Indicators of Water Quality dissolved oxygen –must be between 5 – 8 ppm to sustain life –water movement increases dissolved oxygen –cold water holds more dissolved gases (including oxygen) –increasing temperature or suspended sediments in water will reduce the dissolved oxygen level acidity –pH of about 5.6 is normal for rain and snow –if water gets too acidic (pH below 4.5) fish will die –acid rain or runoff with lots of fertilizers will make the water more acidic How does your water taste? smell? look? How does your water taste? smell? look?
heavy metals –these are dense metals which can accumulate in the environment and cause disease in organisms –3 most common are lead, mercury & cadmium nitrogen and phosphorous –chemicals from fertilizers and sewage –promote algae growth, increased bacteria and decreased dissolved oxygen concentration pesticides –chemicals use to kill weeds or insects –can build up in the food chain and damage populations of plants and animals –often runoff farmers fields or lawns and end up in waterways
salts - many organisms cannot tolerate large concentrations of salt polychlorinated byphenyls (PCBs) –still linger in our environment even though they were banned in 1977 –can cause skin conditions and liver damage biological markers are microscopic organisms present in our water –healthy populations of species such as flatworms, clams and insects can indicate good water quality –organisms such as E. coli can indicate poor water quality
Cleaning Water water is purified in nature by the hydrological cycle → when water evaporates it leaves behind dissolved compounds… and then rain water is of better quality Did you know that a litre of oil costs about 40 cents … while a litre of water costs about $3!
Producing Freshwater distillation –water is boiled in a container –evaporating water leaves impurities behind –the resulting water vapor is collected, allowed to condense, producing clean distilled water reverse osmosis –pressurized salt water is pushed through a semi permeable membrane which filters out the salt
Water Softening hard (fresh) water is common in many areas… including Calgary hard water has lots of minerals in it, such as calcium and magnesium hard water limits the foaming action of soap/detergent and leaves a film on your skin soft water removes some of these minerals