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Dieren en planten

Water

Water circulation is for the planet what blood circulation is for man. Water is continually circulating between evaporated seawater, cloud formation, precipitation, creeks, rivers, lakes and back to seawater. Together with the energy from the sun, this circulation determines the climate on earth and provides for the transportation of minerals, nutrients and other materials.

  • Human influence

    On a smaller scale, people have a much stronger influence on water management than nature. For example, the height of the water level in a polder is regulated by ditches, canals, pumps and sluices, so that farmers can work the land optimally. The water level in nature areas are usually maintained at a higher level because of the benefit for many plants and animals.

  • Saline, brackish or fresh?

    Saline water is salty, at least 3% of the weight is made up of dissolved salts. In other words, there is more than 30 grams of salt per liter in seawater.
    In brackish water, there is between 5 and 30 grams of salt per liter. Water is considered fresh when there is less than 5 grams of salt per liter. Only 3% of all water in the world is fresh water. Around two-thirds of that is frozen in glaciers and polar caps. Much fresh water is under the ground and only 0.3% is surface water.