Water world Flashcards
what is the hydrological cycle?
the hydrological system is a closed system. This means although the worlds water goes round and round none is added or lost from the system so overall the earth does not become wetter or drier.
examples of water and availability and water quality ?
Tourism - the large increase of people visiting new places will take up a vast majority of the water that the local people should be drinking.
Climate change - this will affect rainfall and evaporation causing places to become more arid and more able to have water problems.
Population growth - the more people there are in areas suffering from water shortages the less water their will be to drink.
Industrial development- the growth of manufacturing industry’s depend on water supplies. However they can also release a lot of excess waste into the environment like chemicals in water which could pollute it further.
what factors have come together to cause rainfall to become insufficient .
Rising demand because of population increase.
Rising demand because of changing land use- commercial farming for example
Falling supply because of short or long term changes in climate.
Falling supply because of neighbouring countries taking more water from rivers.
CASE STUDY: WATER IN THE SAHEL. WHAT ARE THE IMPACTS ON PEOPLE?
- Severe drought occurring in 1984-85,2005-2010 , reducing food supply as harvesters failed.
- During dry spells , soil in fields blows away creating dust storms .
- As rainfall has decreased and become more unreliable , people have been forced to move cities.
- Lower rainfall and eroded land leads to desertification.
- Grass and scrub was cleared to allow farming on steep slopes , but drought followed by heavy seasonal rains increased soil erosion , so farming is less productive.
what are the effects of climate change?
Climate change will lead to increased temperatures , increased evaporation and decreased river flow therefore one very likely outcome is increased drought in some places.
What are large scale water management projects?
They usually involve building big dams . currently dams supply: 40% of the worlds irrigated water , 20% of the worlds electricity.
There are around 45,000 large dams worldwide affecting 6 out of 10 major river . They have caused about 80 million people to be forcibly moved from their homes.
CASE STUDY: SMALL SCALE WATER MANAGEMENNT PROJECTS AND GIVE EXAMPLES?
RAINWATER HARVESTING -1500 litre jars are made from local sand , mud brick , cement and copper pipes . The jar collects and stores runoff from a roof via gutters. each jar costs about £35 and can supply four families . The water helps the families get through the dry seasons when rivers run dry and it does not rain.
LIFESTRAW- the Swiss company makes a plastic tube that uses nano-filtration technology to clean dirty water. Life straw comes in individual and family sizes..
The technology removes 99.9% of bacteria , saving lives.
examples of small scale water management projects
Labour intensive Environmentally friendly small scale and not expensive locally controlled and run by locals energy efficient simple technology which can be maintained and repaired by local people.
CASE STUDY: COST AND BENIFITES OF THE LARGE-SCALE WATER MANGEMENT PROJECT THE THREE GORGES DAM.
COSTS-over 26 billion to build
increasingly dirty and polluted because of industry working on its banks.
over 1 million people had to be relocated as a reservoir flooded. Many ancient monuments were ruined.
species may become extinct because of habitat loss such as the Chinese river dolphin.
BENIFITES-stops devastating flooding on the yangtz river as 1954 and 1998.
generates 22.5 gigawatts of electricity and produces no polluted air.
water supply is more reliable
