Water consumption and sources Water consumption can be measured by comparing how much water is being used at home (domestically), in farming (agriculture) and in industry. Global averages: 11% domestic use, 20% industrial use, 69% irrigation use - these vary enormously between regions. In Africa agriculture uses 85% all water used for agriculture while 8% domestic use, and 7% industrial use. In Europe most water used in industry 54%, while agriculture uses 33% and domestic use is 13%. In USA industry is the biggest user with 45% followed by 41% agriculture and 14% domestic. There is a staggering difference in amount of water used per person per day in different parts of the world: USA 600 litres, Europe 300 litres, United Nations recommended minimum 50 litres, Sub-Saharan Africa 25 litres.

Why there are differences in water use Domestic usage:
HIC's use more water than LIC's
HIC's use water for a wide range of domestic practices include personal hygiene (bathing - for a bath 120 to 200 litres and showering - shower 60 to 80 litres), kitchen appliances like dishwashers and washing machines - 70 to 120 litres, toilet use - flush 6 to 12 litres gardening (hosepipes) and other luxury uses like washing cars and filling swimming pools.
In many LIC's high percentage of people don't have piped water coming to their house and have to rely usually on women and children walking to nearest water source. In LIC's it's common for water collectors to have to walk several kilometres every day to fetch water. Once filled pots and jerry cans can weigh as much as 20 kg. Due to difficulty of getting water must be used sparingly. Washing up done by hand and the same water will often be used for personal hygiene. Though may live close to river or lake so can do washing at source.

Agricultural usage:
HIC's use grater amount of water to irrigate crops
Main reason why HIC's use more water is type of irrigation methods used in HIC's like UK have a modern automated spray system this system can operate at 75 litres of water per second just with the press of a button.
Wheras in LIC's ex. China a hand worked bucket which can only produce 2 litres of water a second so long as someone operates it.

Industrial usage:
Industry in HICs is mostly large scale with factories using millions of litres of water in production of various items.
Industry in LICs often small scale with businesses being run from homes or self-built units. The cottage industries often use very little or no water as large multinational companies are moving their factories to many LICs and MICs the amount of water that will be used in industry in these countries is growing rapidly. Ex. In India Coca-Cola uses 1 million litres of water a day

How greater wealth leads to increasing water consumption As country's economy becomes stronger the wealth of the individual increases and there is more money available for luxuries. has been growth in labour saving devices that use a considerable amount of water. As average dishwasher uses 3000 litres of water yearly there is continual increase in domestic water usage. Also been a change in personal hygiene before 1950s common for there to be weekly bath night many houses didn't have fitted bathrooms so the bathwater was heated in the kitchen, brought into living room and poured in a metal bath in front of ire. Often all members of the family would use in turn the water. Now people bath or shower several times a week, bathing and showering is still unusual in rural areas of many LICs. With greater wealth boom in number of holidays and short breaks taken by those in HICs. Growth of leisure and tourism industry has seen demands on the use of water. Golf in Sweden popular and has seen 92% increase in number of golf courses built since 1990. Between 1990 and 2004 have been 603 new golf courses built in the UK all of which need large amounts of water to make the grass grow, cannot rely on water alone. Although number of new courses is now declining there have been many technological improvements in watering systems which automatically water the course at selected times each day, dramatically increasing the amount use. Many new golf courses have artificial lakes included in design the water level in these lakes must be constantly topped up. In countries like Spain that are very dry in the summer so much water is used on golf courses and swimming pools that local communities often suffer water shortages. Authorities consider it's important to keep interest of tourist industry running which provides money for the economy rather than allowing the locals their water.

Where water comes from Groundwater: In some places water soaks into ground and settles in large areas of porous rock like chalk or sandstone. These are like giant sponges that fill up with water, called aquifers. Highest level of water in an aquifers known as the water table. Level of this varies according to whether there is a lot or little rainfall and also if temperatures are high this can lead to water being sucked from the ground and lowering the water table. To extract water from an aquifer a hole is drilled down to below the water table and pressure will cause water to flow up the pipe to the surface where it's stored in tanks and then transferred to areas of need by pipeline. The London basin is an aquifer extraction of water from aquifers can lead to problems, Mexico City is build on a aquifer it has a population of 20 million and to provide water for the growing population the aquifer is being rained quicker than it can be replenished. Areas of the city are sinking, pavements and roads are cracked and walls of buildings are buckled. Monument celebrating Mexico's independence from Spain had to have 23 steps added to reach its base as the city had sunk around it. A water pipe built into the ground in 1934 now 6m above ground. City has stopped pumping water in the city centre instead getting it from wells at the periphery, in recent years this has slowed the sinking of the city to 2cm yearly but some suburbs with many wells continue to sink 45-60 cm each year.

Reservoirs:
Reservoir is an artificial lake of water held behind a dam to store water for irrigation, drinking, recreation, power or other use. Best place for a reservoir is a river valley in an upland area with steep sided slopes which act as natural walls. Rock underneath needs to be impermeable so that the stored water does not leak away. Two main types of reservoir: Direct supply reservoirs store water and supply it straight to a water treatment works, river regulating store water during rainy periods so that the river can be topped up during dry spells - release extra water into the river so that it can be taken out further downstream for treatment and supply. Some reservoirs are entirely underground, in UK Thames Water has many underground reservoirs beneath London built in the 1800s by the Victorians, most of which are lined with thick layers of brick. Honor Oak Service reservoir which was completed in 1909 is largest of type in Europe. roof is supported using large brick pillars and arches and outside surface used as golf course.

Kielder Water:
This is a river regulating reservoir owned by Northumbrian Water, one of the ten water companies in England and Wales and holds 200 billion litres making it the largest reservoir in UK. Constructed between 1975 and 1981 and was opened by Queen in 1982. Took two years for valley of the North Tyne river to fill with water completely once construction was completed the reservoir releases water into the North Tyne river, which joins the Tyne near the Hexham. Water can also be transferred into three of the region's other rivers, huge pumps take water from the Tyne at Riding Mill and transfer it through a tunnel to the River DErwent near the Derwent reservoir, then to the River Wear at Frosterley and then to the River Tees at Eggleston. In this way water treatment works at Horsley on the Tyne, at Mosswood near Consett on the Derwent, at Lumley near Chester-le-Street on the Wear and at Broken Scar near Darlington on the Tees, can all be supplied with water from Kielder. The main conurbations served by the reservoir are Tyneside, Wearside and Teesside.

Why water supplies vary Water supply is uneven, the distribution of rainfall varies from region to region and country to country some places in world have surplus of water and others deficit. Main reason for this is amount of rainfall a place receives, another reason is that some areas with a reasonable amount of rainfall have very high evapotranspiration rates - where the temperature is high and rainfall is quickly condensed into a gas and rises back into the atmosphere. Water doesn't have enough time to enter water stores like groundwater, wettest places in the world like the rainforests and mountainous areas don't support many people whereas some dry areas like Nile valley support high populations. Most areas with little or no water scarcity are in HIC though some are MIC's in South America. The countries suffering a scarcity of water with exception of Australia are MIC's or LIC's. Split between countries with a physical scarcity as they are very arid and very poor who can't afford to access water.

What are the problems associated with water supply in HICs Rainfall and population imbalance:
Population and rainfall of UK is unevenly distributed, one third of the UK's population live in south-east England but this is also the driest part of UK with average annual rainfall of less than 800mm. Least populated areas of UK are in mountain areas of Scotland, Wales and north-west England here most rain falls: over 2000mm.

Leakage:
In London more than half of water mains more than 100 years old and around a third more than 150 years old. Ageing pipes don't affect the quality of water but the problem is they leak. 30% of the water supply is lost through leaks and cracks, more than 3.5 billion litres of water lost daily through broken and leaking pipes in England and Wales in 2006. More than a fifth of the 15 billion litres supplied by UK water system each day and more than the entire amount of bottled water drunk by Britons in a year. Water leaks daily through broken pipes is a loss to the economy between 1,512,000 pounds and 3,600,000 pounds because this is how much it will cost to re-treat the water to make it drinkable. Will always be water leaks as the pipes wear out and suffer damage from environment ex. from freezing weather and impact of traffic on the roads. Though water companies have also been very slow in repairing and replacing the pipes.

Seasonal rain imbalance:
Problem with seasonal supply of water in many of Mediterranean holiday areas places like Costa del Sol - Spain receive most rainfall in winter months and little in summer. In the six months of May to October, Malaga receives only 70mm compared with 385mm in other six months. Though it's in summer months when greatest amount of water required influx of tourists want swimming pools and well-watered golf, foo mean crops must be heavily irrigate. In 2008 problems in southern Spain, Murcia undergone resort-building boom in recent years. Farmers fighting developers over water rights, fighting one another over who gets to water crops - buying and selling water on rapidly growing black market mainly from illegal wells. Spanish Ministry from the Environment called on resident and holidaymakers to save water as Spain started worst summer of drought since 1947: Dry winter and spring left national water reserves almost 50% down on total capacity with no expectation of rain in the driest areas until October. Murcia and the Valencia regions were most critical with reservoirs on the Segura and Jucar rivers running at 29 and 16% respectively of total capacity. To make situation worse was dry hot summer - temperatures were 2 degrees above average for July, August and September.

Variability:
As rainfall in an area cannot be relied upon there are often times of deficit, UK rainfall in 2005 and 2006 long periods where rainfall was below average, would lead to problems like reservoir levels dropping and water restrictions, for example, hosepipe bans. By contrast 2007 saw long wet period in summer which lead to reservoirs and aquifers being replenished.

Problems associated with water supply in LICs Problem in LICs is high proportion of population that don't have access to clean piped water leads to a range of diseases which can be caused by resource exploitation'
Fact file: Water supply in LICs

1.1 billion people in world don't have access to safe water - one-sixth of world population
2.6 billion people in world don't have access to adequate sanitation - two-fifths of the world's population
1.8 million children die each year by result disease caused by unclean water and poor sanitation - amounts to 5000 deaths a day
Any given time half of population of developing world suffering from one or more of main diseases associated with inadequate provision of water and sanitation
Around 90% of incidences of water-related diseases due to unsafe water supply, sanitation and hygiene and mostly concentrated in children in developing countries
Any one time half of developing world's hospital bed occupied by patients suffering from water-related diseases
Intestinal worms infect about 10% of population of developing world intestinal parasitic infections can lead to malnutrition, anaemia and stunted growth
One gram of human faeces contain 10,000,000 viruses, 1,000,000 bacteria, 1,000 parasite cysts, 100 parasite eggs
India spends eight times more on military budgets than on water and sanitation. Pakistan spends 47 more times. Diarrhoea claims 450,000 lives each year in India more than in any other country

Water-related diseases:
Dirty contaminated water is responsible for range of health problems including:

Dysentery - infectious disease of large intestine, symptoms are diarrhea (often containing blood), sickness and stomach cramp
Malaria - caused by a parasite which is transmitted through bites of infected mosquitoes, symptoms of malaria: fever, headache and vomiting, usually appear between 10 and 15 days after the mosquito bite. If not treated malaria can quickly become life-threatening by disrupting the blood supply to vital organs
Bilharzia - caused parasitic worms which get into the blood system and can cause kidney failure
Trachoma - caused parasites in contaminated water and will lead to blindness if untreated

Pollution of water courses through resource exploitation
Many indigenous tribes in Amazon region suffered from water contamination due to mining operations and oil exploitation. Contamination led to increased risks of cancer, abortion, dermatitis, fungal infection, headaches and nausea. Drinking, bathing and fishing water contain levels of toxins higher than safety limits set by US Environmental Protection Agency. Unlined water pits provide major source of pollution in the Oriente region of Ecuador. Over years the toxic contents of waste pits have leeched into rivers contaminating the larger ecosystem and sending toxins downstream into Peru. Since was no other options for obtaining water, local people now depend on these contaminated sources for drinking water and slowly poisoning themselves. Childhood leukemia rates are four times higher in area than in other parts of Ecuador; children as young as a few months of age died of leukemia. Achuar people who lived for thousands of years in the rainforest of Peru, allege that the Occidental Petroleum company contaminated their territory during more than 30 years of oil drilling. Water contains high concentrations of hydrocarbons and heavy metals, hydrocarbons and chlorides causing serious physical and mental health problems, including cancer and genetic deformities. Achuar people say pollution is destroying fragile ecosystem in which they live, killing fish and wildlife, contaminating their water source and seriously damaging their health. Survey carried out by Pru's Ministry of the blood of more than 98% of Achuar exceeded safe levels. More than 66% of children had levels of lead in their blood which exceeded the maximum safe amount.

Management of water usage and resources How water usage is being managed in HICs
Domestic:
water can be used more efficiently in the house as shown in the below diagram

	Creado por Chima Power hace más de 9 años

Edexcel Gcse