Human interference affecting water cycle:
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Salinisation → more water being pumped up, salt leaking in (over abstraction water quality )
- Building of dams affects run off, upstream lots of water downstream not so much due to it evaporating.
- Urbanisation, build more houses surface area, depletion of ground water.
- Evapotranspiration, deforestation stops this process. Chopping down trees could mean larger surface area for run of, water scarcity takes place.
- Cloud seeding (making own rain, acidity ruins quality)
- Transferring water, more water in one area less in another.
Where is all the water?
97.5% = Ocean water 2.5% = Fresh water 0.4% = Surface & Atmospheric water
Groundwater:
- Most rainfall soaks into soil, some further into he ground (infiltration)
Trickles downwards into rocks and becomes groundwater.
- Groundwater is vital in supporting wetlands and stream flows.
- Water table = level at which the rock has become saturated. An aquifer is water bearing rocks that are saturated.
Water supply is controlled by climate factors!!
Water supply is a balance between precipitation totals and evapotranspiration potentials and is controlled by aquifers.
Water pollution!
2 types:
Water Bourne = Typhoid and Cholera -> oral face contamination due to lack of sanitation
Water washed diseases: = Scarce water (drinking and cooking) 1st demand
Washing (leprosy) and Irrigation (luxury) 2nd demand
Mosquitoes → malaria, dengue fever, river blindness (water is a breeding ground)
Not just about quantity but the quality of water!
Ground water = pollution less obvious than surface water → aquifers become polluted, feed surface water = Salinisation due to over abstraction.
Salinisation = the process whereby soluble salts accumulate within the soil.
‘’Dilutions is the solution to pollution!’’
With over 8 billion people on the planet, disposing of sewage waste is a major problem. In developing countries, many people still lack clean water and basic sanitation (hygienic toilet facilities). Sewage disposal affects people's immediate environments and leads to water-related illnesses such as diarrhoea
However in theory Sewage = natural substance that can be broken down harmlessly in the environment. (It contains all kinds of chemicals e.g. pharmaceutical) ☹ people are sick virus is in the sewage and can become air Bourne in environment, can catch cholera etc from rivers and seas.
Nutrients...
Sewage can be a fertiliser→ returns important nutrients back to environment. Chemical fertilizers used by farmers also add nutrients to the soil... HOWEVER →
- Drains into rivers and seas adds to fertilizing effects of sewage
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Growth of algae or plankton, takes up oxygen → takes o2 from water which kills other life forms!
Thermal pollution....
Factories releasing cooling water into rivers...
Salinisation of groundwater →
Deeper the well, more water being pumped up collects more salt water quality.
Cone of exhaustion →
Build the biggest well, getting all the water everyone else’s dries up. Sell water to others leads to economic scarcity!
Deepor Beel
- Permanent fresh water lake in the former channel of the Brahmaputra River.
- South of the main river.
- South west of Guwahati city.
- It is a large natural wetland having great biological and environmental importance.
- It’s the only water storage basin for the city.
- Agricultural activates and farmers depend on the water lake.
- Designated as a ramsar site (conservation of the land)
Deepor Beel is on a flood plain → when it floods water can flow into it.
Toxico, Ecuador
One of the most diverse regions in the world.
3 distinct regions (minus Galapagos):-
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El Oriente → Amazon part of rainforest in the east.
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La Costa → Western Pacific coast.
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La Sierra → Andes Mountains, centre of country.
Operations up to 1992, Texaco spilled 17 million gallons of oil from pipeline and dumped 18 million gallons directly into the rainforest, contaminating 1,700 square miles leaving extremely dangerous conditions.
Oil was dumped into pits around the jungle, water spread into the rivers. Soil and rivers are so polluted that nothing grows, fish are all dying and drinking water is now poisoned.