We know that brightly-coloured fish are numerous around coral reefs, that sharks hunt, that wrecks are encrusted with many unfamiliar organisms. Such features are exotic and remote from our every day view of water bodies and we can only estimate the depth of water in local lakes, or the topography of the sea bed of coastlines we know well. Our lack of awareness of what goes on beneath the surface of water bodies creates problems.
Excessive dumping of organic matter brings pollution and toxic organisms; pesticides and chemical spillages make water poisonous; fishing and whaling stocks are threatened. There are many other examples and all point to our need for a better understanding of water bodies and the processes that occur within them. Uses of water by humans. Drinking water and the disposal of wastes. All living organisms are dependent on water to complete their life cycles as water is an essential component of cells.
The earliest sources of water for human consumption were rivers, lakes and ponds from which water was collected for drinking and cooking. Waste was then discharged on to local land to fertilise crops, or into ponds and rivers downstream from settlements to increase the production of fish. Although urban planning has existed for thousands of years, it is only relatively recently that we have learned the consequences of pollution both of drinking water supplies and of habitats.
Nevertheless, human populations still encounter major problems with their water supply, and provision of clean water to communities throughout the World remains an important challenge.
Water has always been used by humans as a means of transport. Early humans used rafts and simply-constructed boats to move on the surface of water and thus migrate, or carry cargo from one location to another.
After societies developed there was a need to explore and conquer new territories and some migrations on water took place over long distances. As towns and cities developed near rivers, coasts or on lakeshores, transport was needed to conduct trade and to bring in essential supplies, most of which could no longer be provided locally.
This led to trading and shipping routes but this is a slow method of transport, although large cargoes are still carried by sea. Providing human food from water. Water bodies also contain important sources of food. Aquatic plants and animals, both vertebrates and invertebrates, have been harvested for a very long time and remain a staple diet of many human communities.
As settlements grew larger and transport links developed, food acquisition became commercialised and stocks were no longer an easily monitored local resource. This commercialisation has led to over-exploitation of natural stocks and we have developed farming techniques to supply demand, although the farming of marine and freshwater organisms by human societies has ancient origins.
Fresh water is needed to irrigate terrestrial or emergent crop plants and is drawn from rivers, lakes, impoundments and containers of many kinds. Many rivers also provide fertile alluvium when water levels drop after seasonal flooding.
Irrigation schemes use channels and dikes to duct water to crops that are sometimes maintained under water, as in rice paddies. Large-scale irrigation schemes often impound rivers to allow a more regular discharge of water than would occur naturally, when droughts, unpredictable pulses of water, and seasonal floods were the norm.
This has the advantage of extending growing seasons and ensuring the regular production of crops. Water is of special significance in deserts where rainfall is very low or non-existent. Oases are essential in allowing human colonisation and in providing watering holes for pack animals used in trade and migration. Driving machinery, or generating power, using water. Moving water provides an important source of energy that can be harnessed to drive machinery or generate power. Until the advent of large steam engines, mill streams were cut to divert some river water over a water wheel used to power rotating mill wheels or other machinery.
Often, an upstream lake was created by impoundment to ensure that there was a near constant head of water. This principle developed into the use of turbines for power generation, large rivers being dammed and water passing though pipes to generators, often with a considerable drop in vertical water level to ensure maximum power output.
Although some countries are dependent on hydroelectric power generation for a significant amount of their power supplies, this source is usually secondary to power generation as a result of burning fossil fuels or from nuclear reactions.
The sea is also used for generating power, advantage being taken of tidal cycles or the action of waves. At present, these technologies are expensive to develop, produce, and maintain for the amount of power that is generated. Most of us like to spend time near water. Many holidays are taken by the sea or large lakes so that we can enjoy paddling, swimming, boating, fishing and other aquatic recreations. Sport fishing is a major pastime in many parts of the world and anglers are among the most acute observers of the aquatic world.
Water is also important aesthetically, featuring in paintings, ceramics and garden design as well as being an inspiration to composers of music. The range of water bodies found on Earth. The area of the Earth's surface that is covered with water. More than two thirds of the Earth's surface is covered with water and most of that is sea water.
There just wouldn't be any you, me, or Fido the dog without the existence of an ample liquid water supply on Earth. The unique qualities and properties of water are what make it so important and basic to life. The cells in our bodies are full of water. The excellent ability of water to dissolve so many substances allows our cells to use valuable nutrients, minerals, and chemicals in biological processes.
Water's "stickiness" from surface tension plays a part in our body's ability to transport these materials all through ourselves. The carbohydrates and proteins that our bodies use as food are metabolized and transported by water in the bloodstream. No less important is the ability of water to transport waste material out of our bodies. Looking at water, you might think that it's the most simple thing around. Pure water is practically colorless, odorless, and tasteless.
But it's not at all simple and plain and it is vital for all life on Earth. Where there is water there is life, and where water is scarce, life has to struggle or just "throw in the towel. Surface tension in water might be good at performing tricks, such as being able to float a paper clip on its surface, but surface tension performs many more duties that are vitally important to the environment and people. Find out all about surface tension and water here.
We need to take the statement "Water is the universal solvent" with a grain of salt pun intended. Of course it cannot dissolve everything, but it does dissolve more substances than any other liquid, so the term fits pretty well.
Water's solvent properties affect all life on Earth, so water is universally important to all of us. Plants and trees couldn't thrive without capillary action.
Capillary action helps bring water up into the roots. With the help of adhesion and cohesion, water can work it's way all the way up to the branches and leaves. Read on to learn more about how this movement of water takes place. Adhesion and cohesion are important water properties that affects how water works everywhere, from plant leaves to your own body.
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