WATER

Water usage differs greatly from country to country, depending on how developed a nation is. Other influencing factors include agriculture and supply networks.

The global demand for water

The amount of water used in the world every day is very uneven. MEDCs use more water than LEDCs - households, farming and industry all demand water.

What is the water used for?

What the water is used for depends on the country. The pie charts below show the difference in water usage in four countries.

• In general LEDCs (like Bangaldesh and Malawi) will have most of their water used in agriculture (farming) and little in industry or domestic use. Bangladesh has farming as a large part of its economy so a large percentage of their water is used for that purpose.
• MEDCs (like the UK) have a more significant use of water for domestic reasons. MEDCs also tend to have a higher percentage for industrial use.
• There are exceptions. The USA is an MEDC, but it still has a high amount of water used for agriculture because there is also lot of farming across the country.

The % share of total water usage:

  

The amount of water used

The amount of water used per person in each country changes dramatically. The bar chart shows the total amount of water used per person in selected countries.

The graph shows that people in MEDCs use far more water than those in LEDCs

Why are there so many differences in the way water is used?

Agricultural irrigation in a soya bean plant field, Iowa, USA

Agriculture

• In MEDCs irrigation is mechanised. Sprinklers or timed irrigation feeds are used. Where agriculture is common, vast amounts of water can be released at a touch of a button.
• In LEDCs irrigation channels are prone to loosing water through evaporation.

Industrial use

many women mixing ingredients to make cow dung soap in India.

• Industries in MEDCs can be on a large scale, and so demand a lot of water. Corus Steelworks in South Wales is an example of an industry which needs a large water supply.
• LEDCs have smaller scale cottage industries. They demand less water in the production of items. However as more multinational companies locate in LEDCs there will be more demand on water. For example in India Coca-Cola uses over a million litres of water a day to produce drinks.

Domestic water use

• In MEDCs there are a lot of facilities which demand water use. For example showers, baths, washing machines and swimming pools.
• In LEDCs many people do not have access to piped water and so use it more sparingly. Water may be brought to the home from a well or stream.

As a country becomes more wealthy, there will be an increase in its demand for water. Higher levels of industrialisation and more domestic goods such as washing machines all lead to an increase in demand for water. With greater wealth there is also more demand for spas, golf courses and even baths and showers.

Management of water usage in MEDCs

There are problems in supplying water in MEDCs. These are:

• the quality of available water
• distribution
• the seasonal changes in supply
• broken pipes when transporting water

Both water supply and the demand for water need to be managed.

Managing water supply

In the UK there is a big issue with water supply. Areas which receive high amounts of rainfall tend to be sparsely populated.
One third of the UK population live in South East England. This is also the driest area in the UK.
Ways to manage the water supply include:

• making sure the broken pipes are mended (as water loss from broken pipes can be as much as 30 per cent)
• using reservoirs and dams in one area to pipe water into large urban areas
• making sure that the water supply is of good quality - reducing fertiliser use on farms helps this

In December 2010 over 40,000 people had water supply problems in Northern Ireland. One reason was because the water pipes were quite old - some over 60 years old. This meant that when there was a spell of very cold weather, many pipes could not cope and the pipelines failed.

Managing water demand

The demand for domestic water can be monitored. Households with water meters in the UK use less water in general than those without. Households can also conserve water. Ways to do this are:

• having a shower not a bath
• collecting rainwater to use on the garden rather than tap water
• recycling bath water to flush the toilets with
• installing more efficient versions of appliances such as washing machines

Industries can also look to recycle waste water. For example, when using water for cooling in steel-making, the water can be recycled again and again in the process.
In agriculture, drip-feed irrigation systems could be used rather than sprinkler systems.

Management of water usage in LEDCs

There are problems in supplying water in LEDCs. These are:

• lack of availability of clean water
• diseases spread via the water supply
• water pollution

Managing water resources

One in eight people of the world population do not have access to safe water. Sixty million children are born each year in LEDCs who do not have access to safe water.
In LEDCs using appropriate technology is usually the best way to manage supply.

Women and children collecting drinking water from a manmade well in Senegal.

• Wells, dug by hand, are a common way of accessing water - but the supply can be unreliable and sometimes the well itself can be a source of disease.
• Gravity-fed schemes are used where there is a spring on a hillside. The water can be piped from the spring down to the villages.
• Boreholes can require more equipment to dig, but can be dug quickly and usually safely. They require a hand or diesel pump to bring the water to the surface.

In addition to locating new sources of water, some strategies help to reduce the need for water. These include:

• harvesting (collecting) rainwater landing on buildings
• recycling waste water to use on crops
• improving irrigation techniques
• growing crops less dependant on a high water supply
• minimising evaporation of water

As LEDC cities grow, so does the demand for water. The problem doesn't end when water supplies have been improved and pipes put in place. The water has got to come from somewhere, and the source of supply may be scarce. It is LEDCs which have the lowest access to safe water as the map below shows:

Many countries in Africa and the Far East have a below average population size that have access to safe water.

Managing safe water

Without safe water people cannot lead healthy and productive lives. Areas which are in poverty are likely to remain in that way. One example where non-governmental charities have helped break this cycle is in Nigeria.
In Nigeria only 38 per cent of people have access to sanitation. A community led total sanitation project (CLTS) was started by one non-governmental charity. In one year, the project helped 2.5 million people gain access to sanitation. Areas with poor infrastructure, high rates of illness and poverty were identified, and the charity worked with the local population in these areas. The teams worked with the people and educated them as to how poor hygiene and sanitation can make people ill. This included how it can also make others in the community ill. Toilets were built using local, affordable materials. Key people in the community led the work.
 Too little water - drought

Droughts occur when a long period of abnormally dry weather leads to a severe water shortage. Droughts are also often caused by the activity of humans and can have devastating effects.

Human activities causing drought

Human activities that can help trigger droughts include:

• Widespread cutting down of trees for fuel reduces the soil’s ability to hold water - drying out the ground, triggering desertification and leading to drought.
• Constructing a dam on a large river may help provide electricity and water to irrigate farmland near the reservoir. However, it may also cause drought downstream by severely reducing the flow of water. 

Effects of drought

Parched ground during drought in Namibia

• Droughts endanger lives and livelihoods through thirst, hunger (due to crops dying from lack of water) and the spread of disease.
• Millions of people died in the 20th century due to severe drought and famines. One of the worst hit areas was the Sahel region of Africa, which covers parts of Eritrea, Ethiopia and the Sudan.
• Droughts and famines can have other geographical impacts. If drought forces people to migrate to a new home it could put pressure on resources in neighbouring countries.
• Droughts can have a severe impact on MEDCs as well as LEDCs. Droughts have caused deaths in Europe in recent years - especially amongst the elderly. In the UK in summer 2006, there were hose-pipe bans and campaigns to make people save water.

Case study: drought in the Sahel

Map showing location of Sahel

Food for distribution Yabelo area, Southwest Ethiopia

The Sahel region of Africa has been suffering from drought on a regular basis since the early 1980s. The area naturally experiences alternating wet and dry seasons. If the rains fail it can cause drought.
In addition to natural factors, the land is marginal. Human activities such as overgrazing, overcultivation and the collection of firewood can lead to desertification, particularly when combined with drought conditions.
The result is crop failure, soil erosion, famine and hunger: people are then less able to work when their need is greatest. It becomes a vicious circle and can result in many deaths, especially among infants and the elderly. In Niger in 2004, the situation was made worse when a plague of locusts consumed any remaining crops. In these cases, people rely on food aid from the international community.
On its own, food aid is unsustainable in the long term. What is really needed is development aid, which involves educating the local community in farming practices. 
DESERTIFICATION
Desertification of the arid lands of the world has been proceeding--sometimes rapidly, sometimes slowly--for more than a thousand years. It has caused untold misery among those most directly affected, yet environmental destruction continues. Until recently, few if any lessons seemed to have been learned from the past. It was not until the 20th century--when easy land expansion came to an end--that governments and people finally realized that continued careless degradation of natural resources threatened their future.
INTERNATIONAL DIRECTIONS
The decade of the 1950's witnessed the first worldwide effort to call attention to the problems and potentials of arid regions. It started when the United Nations Educational, Scientific, and Cultural Organization (UNESCO) launched its Major Project on Scientific Research on Arid Lands in 1951.
The impetus generated by the UNESCO project led to expanded interest in, and support of, arid lands studies throughout the world. By 1970, knowledgeable scientists were well aware of the magnitude of the land destruction that had taken place in the past, and that was becoming even more serious as population pressures increased.
At about the same time, one event served to focus world attention on desertification: the 1969 to 1973 drought in the African Sahel. Recognition of the severity of the drought affecting six countries on the southern border of the Sahara (Mauritania, Senegal, Mali, Upper Volta, Niger, and Chad) was slow to develop.
Desertification Characteristics in Spain
During the past several centuries, heavy grazing by sheep and goats has led to the destruction of much of the herbaceous and woody vegetation on the noncultivated land (Albareda, 1955). Water erosion has been severe on the overgrazed slopes as a result of the loss of vegetative cover and the torrential character of the rains. Cutting of wood for fuel and construction and the extension of dryland farming into the pasture lands has accompanied overgrazing. Plant cover has changed to a more xeric type and surface runoff has increased.
A monoculture of grain in the cultivated regions has depleted the native fertility of the soil and has been responsible for increasing the susceptibility of the land to wind and water erosion. Extended droughts from time to time have served to accelerate desertification. Water erosion is severe nearly everywhere on sloping land.
Salinization and waterlogging do not affect a high percentage of the total cultivated land in Spain but important and large areas of affected soils do occur in irrigated valleys. The major salt-affected areas in the northeast are in the Ebro River watershed in the vicinity of Zaragosa and Herida. Seepage water from irrigation on the higher land has caused waterlogging and salinization of lower-lying areas (Martinez, 1978). Gypsum is a common constituent of the soils.
The other major salt-affected areas are in southwest Spain near the coast. The soils are composed of fine-textured sediments that were subjected regularly to flooding by seawater in the past. Surface and internal drainage of the irrigated land is poor and water tables generally are close to the surface. Pumping is required to lower the water tables (Ayers et al., 1960).
Magnitude of Desertification
Approximately 50 percent of Spain is arid. In the arid regions about 70 percent is moderately desertified and 30 percent is severely desertified
Virtually all of the rangeland has suffered severe land degradation. Range productivity is probably stabilized at a low level now, with little improvement anywhere. Erosion continues on the extensive dryfarm lands except in a few places where soil and water conservation measures have been instituted. Soil fertility remains low.
Salinization and waterlogging affect about 240,000 hectares of irrigated land to various degrees (Ayers et al., 1960). Reclamation has been undertaken in several areas. Because of the need for more agricultural production and the gradual worsening of the salt problem, irrigation has received special attention in recent decades. Much remains to be done.
Soil and water conservation techniques for dryland farming are known but their application to the field is limited. Range management is not a well-supported science in Spain. Considerable progress has been made in the reclamation of saline soils and procedures for doing so are quite well-known (Martinez, 1978).
Salinization of aquifers:

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