OUR BLUE PLANET, WATER PLANET

Water Resource Management As much as 70% of the Earth’s Surface is covered by water; Of those, 97% is contained in oceans as salt water, and, thus, it isn’t proper for drinking or irrigation; Of the remaining 3% that is freshwater, 2,7% is found frozen in icebergs, mountain tops and glaciers. The rest 0,3% is found in rivers, lakes, waterbeds and aquifers. Therefore, water is considered a scarce and valuable resource in many parts of the world

So being, water is a resource that has to be used wisely and must be conserved efficiently; The need to manage water arises in response to matching the supply of water to people with their domestic and industrial needs – such as irrigation, household use (cleaning, bathing, cooking etc.), manufacturing, recreation and navigation;

TYPES OF WATER SCARCITY Physical Water Scarcity: Where the demand for water is greater than the supply of water. Physical water scarcity does not have to be an arid environment, because there demand for water in arid environments (deserts) is not normally low meaning that there is no shortage. Economic Water Scarcity: Where there is water available, but for some economic reason it is not possible to fully utilize the source of water. This might because extraction or transportation costs are too high, or because the water is polluted and it is not possible to treat it.

WATER SUPPLY X WATER WITHDRAWAL (USE)

VIDEO RESOURCES: WATER SCARCITY dded&v=ftTxkzVbev0 dded&v=ftTxkzVbev0

INFOGRAPH: WATER SUPPLY, DEMAND AND CONSUMPTION WORLD INFOMAP

That are estimates from the International Food Policy Research Institute that calculate that by 2025 the world will use around 6000 cubic kilometers of water, raising % in comparison to 1995; This increase will limit the amount of water available for use in irrigation, consequentially restricting food production increases in some parts of the world;

Although the world has abundant supplies of water, they are unevenly distributed both within and among countries. In some areas of the world, water use is growing so rapidly that surface stores are being depleted and even underground reserves are shrinking more rapidly than they can be replenished. One third of the world’s population (thus more than 2 billion people) live in countries that are experiencing moderate to high stress on their water supplies, which means that their consumption levels exceed 20% of the available supply.

Unfortunately, it is expected that this situation will become worse in the decades ahead as the demand for water (from industrial activities, for human use, for sanitation, for irrigation, for transportation, for energy, etc.) increases more and more; The UM estimates that by 2025, two-thirds of the world’s population will live in countries experiencing moderate to high stress on their water supplies. Much of the additional demand for water is expected to come from manufacturing, and if present trends of growth in manufacturing continue, global industrial water use will double between 2000 and 2025.

Globally, agriculture accounts for 70% of water use, and the use of water to this purpose is expected to increase between 50% and 100% over the same period, so the situation will be unbearable. As disparities decrease, LEDCs will start developing themselves in the next decade or so; therefore, it is estimated that the majority of the increase in water demand will come from these countries, once industrial growth will occur, as well as population growth;

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Causes of Water Shortages Water shortages can be divided into a number of categories. As mentioned above, physical water shortages is when there is not enough surface or ground water to meet the demand for it. Economic water shortages is when water exists, but for some reason it can not be fully utilised, maybe because extraction and piping is too expensive or treatment of polluted water is too expensive and the technology does not exist. Population Growth: As with many of the world's resources, they are coming under increasing pressure as the world's population grows. The world's population now stands at about 7 billion, all of whom are placing increasing on water resources as they develop and get richer. Pollution: As the world's population grows so does the demand for agricultural and industrial products. Our thirst for agricultural products is increasing the use of fertilisers and pesticides which often run off into rivers and lakes or leach down to groundwater stores. Like wise our increasing demand for industrial and at times relaxed environmental regulations mean more chemicals and metals are being released into our water sources. Sewage treatment also often lags behind population growth so increasingly our rivers and lakes are being polluted by sewage. Sewage: With rapid urbanisation taking place in many cities around the world, infrastructure often does not keep up with new arrivals. The growth of informal settlements without proper sewage treatment can mean that human waste is often pumped directly into water sources. However, this is not only a problem in LEDCs, in London the sewer system can not cope and an estimated 39 million tonnes of sewage are dumped in the River Thames annually.

Domestic Demand: The demand from households is not only increasing because there are more households in the world, but also because the amount of water they want is increasing with development. For example as peoples income increases and they move into permanent residences, they demand flush toilets, bath/showers, washing machines, dishwashers and green gardens, all of which use large amounts of water. Agricultural Demand: As can be seen in the graph below, agricultural places by far the biggest demand on water. With a growing population, global warming and the movement in to less favourable agricultural regions, the demand from agriculture is only likely to increase in the future. Industrial Demand: As the world's population grows and becomes richer our demand for industrial products grows. Many industrial products, particular things like processing metal use huge quantities of water and place increasing demand on resources. Also mining for the raw materials used in manufacturing use large quantities of water.

Climate Change: Climate change is impacting the availability of water in many ways. Global warming maybe releasing freshwater from glaciers and ice shelves,but unfortunately much of it is running directly into the oceans. The subsequent rising sea levels are threatening many coastal freshwater wetlands as well as increasing the risk of saltwater intrusion into aquifers. Warmer temperatures are increasing the amount of evaporation from rivers and surfaces stores. Political: In many countries or regions, water sources are shared e.g. the River Nile flows through eleven countries. At times some countries control large percentages of the shared resource, leading to shortages for other countries. Follow the link and read how Egypt and the Sudan control the majority of the Nile's water. Mismanagement: If water is not used sustainably or inappropriately then water shortages can occur. One of the most famous examples is the Aral Sea. The Aral Sea is located on the border of Kazakhstan and Uzbekistan. Water was taken from the two rivers that fed the Aral Sea to irrigate the desert and grow cotton. Unfortunately so much water was needed to grow cotton in the desert, that no water reached the Aral Sea and it began to dry up, causing huge water shortages. For more details about the case study, following the link Groundwater Depletion: If water is used unsustainably i.e. more is taken out than is being recharged then aquifers can suffer from salinisation and saltwater intrusion. If you increase the concentration of water it can become too salty for human use. Also if you drain aquifers near coastal areas, then they can become full of saltwater, again making them useless Energy Production: Although HEP is the most obvious form of energy that uses water, this water is released into rivers once it has passed through the dam. Other types of energy that uses large amount of water for cooling e.g. coal and nuclear power, may pollute water or see it evaporated removing it from local use.

Problems Caused by Water Shortages and Water Pollution Drought: If there are economic or physical water scarcity and water stress exists then drought can occur. Drought is below average supply of water over a prolonged period. Because drought is below average supply of water, even relatively wet country's like the UK can suffer from drought. Crop Failure: If there is a shortage of water and farmers can not irrigate their crops then they begin to die. Livestock Deaths: If livestock don't have enough water to drink they will begin to die. Famine: If cops are failing and livestock are dieing then people will become undernourished and suffer from famine. Groundwater Depletion (subsidence and saltwater intrusion): If aquifers begin to dry up or are used unsustainably, then the ground above can subside (collapse) or the aquifer can suffer from salinisation or saltwater intrusion. Subsidence is a problem common in parts of Mexico City. Conflict: If there is a limited supply of water and water resources are shared conflict can arise. Many of the ongoing border disputes between Israel and Palestine are blamed on water shortages Refugees: If there is drought and famine then people are forced to relocate or face death. Unfortunately many of the countries that suffer from drought and famine have poor neighbours so refugees will be arriving in countries that are least able to cope. Disease: Dirty water can attract mosquitoes which can increase diseases like dengue and malaria. Dirty water can also cause the spread of diseases like hepatitis A and typhoid as well things like diarrhea. Eutrophication: Run-off from farms containing fertiliser can lead to eutrophication. Eutrophication is the excess growth of algae causing water to not oxygenate properly or receive enough light. This can cause plants and animals to suffocate and die. Biodiversity Loss: Dirty water and eutrophication can cause loss of biodiversity in wetland environments, but also just like humans can die of thirst and starvation, so can plants and animals. Big animals like elephants which require large amounts of water often die in African droughts.