A term that refers to bodies of water such as ponds, lakes, rivers and streams containing low concentrations of dissolved salts and other total dissolved solids. A pond is a body of water smaller than a Lake, both being examples of Terrain features Although the term pond is universally used to describe waterbodies that A salt, in Chemistry, is defined as the product formed from the neutralisation reaction of Acids and bases. Total Dissolved Solids (often abbreviated TDS) is an expression for the combined content of all Inorganic and organic substances contained in a liquid Freshwater is an important renewable resource, necessary for the survival of most terrestrial organisms, and is required by humans for drinking and agriculture, among many other uses. A natural resource qualifies as a renewable resource if it is replenished by natural processes at a rate comparable or faster than its rate of consumption by humans or other users Water of sufficient quality to serve as drinking water is termed potable water whether it is used for drinking or not Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture The UN estimates that about 1. The United Nations ( UN) is an International organization whose stated aims are to facilitate cooperation in International law, International security 2 billion people (18 percent of the world's population) lack access to safe drinking water. [1]
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Numerical definition
Freshwater is defined as water with less than 0. 5 parts per thousand dissolved salts. Salt is a Dietary mineral composed primarily of Sodium chloride that is essential for Animal life but toxic to most land plants [1] Freshwater bodies include lakes and ponds, rivers, some bodies of underground water and many kinds of man-made freshwater bodies, such as canals, ditches and reservoirs. A lake (from Latin lacus) is a Terrain feature (or Physical feature) a body of Liquid on the surface of a world that is localized to the A pond is a body of water smaller than a Lake, both being examples of Terrain features Although the term pond is universally used to describe waterbodies that "Riverine" redirects here For the use of that term in Maritime geography, see there Groundwater is Water located beneath the Ground surface in Soil pore spaces and in the Fractures of lithologic formations The ultimate source of freshwater is the precipitation of atmosphere in the form of rain and snow. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five Rain is Liquid precipitation. On Earth it is the condensation of atmospheric Water vapor into drops heavy enough to fall often making it to "Snowfall" redirects here For other uses see Snow (disambiguation or Snowfall (disambiguation.
| Water salinity based on dissolved salts in parts per thousand (ppt) | |||
|---|---|---|---|
| Freshwater | Brackish water | Saline water | Brine |
| < 0. Saline water is a general term for Water that contains a significant concentration of dissolved Salts ( NaCl) Brine (lat saltus) is Water saturated or nearly saturated with Salt (NaCl 5 | 0. 5 - 35 | 35 - 50 | > 50 |
Water distribution
Access to unpolluted freshwater is a critical issue for the survival of many species, including humans, who must drink freshwater in order to survive. Only three percent of the water on Earth is freshwater in nature, and about two-thirds of this is frozen in glaciers and polar ice caps. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. A polar ice cap is a high- Latitude region of a Planet or moon that is covered in Ice. Most of the rest is underground and only 0. 3 percent is surface water. Freshwater lakes, most notably Lake Baikal in Russia and the Great Lakes in North America, contain seven-eighths of this fresh surface water. Lake Baikal (о́зеро Байка́л Ozero Baykal, ˈozʲɪrə bʌjˈkɑl Байгал нуур Baygal nuur) is in Southern Siberia in Russia The Laurentian Great Lakes are a chain of freshwater lakes located in eastern North America, on the Canada–United States border. Swamps have most of the balance with only a small amount in rivers, most notably the Amazon River. The Amazon River (Rio Amazonas Río Amazonas of South America is the largest river in the world by volume with a total river flow greater than the next top ten largest rivers The atmosphere contains 0. 04% water. [2] In areas with no freshwater on the ground surface, freshwater derived from precipitation may, because of its lower density, overlie saline ground water in lenses or layers.
Aquatic organisms
Freshwater creates a hypotonic environment for aquatic organisms. Tonicity is a measure of blood capacity or effective osmolality in cell Biology. This is problematic for some organisms, whose cell membranes will burst if excess water is not excreted. Some protists accomplish this using Contractile vacuoles, while freshwater fish excrete excess water via the kidney. Protists (ˈproʊtɨst are a diverse group of eukaryotic Microorganisms Historically protists were treated as the kingdom Protista but this A contractile vacuole is a sub-cellular structure involved in Osmoregulation. Fresh water fish are Fish that spend some or all of their lives in Fresh water, such as Rivers and Lakes with a Salinity of less The kidneys are complicated organs that have numerous biological roles [3] Although most aquatic organisms have a limited ability to regulate their osmotic balance and therefore can only live within a narrow range of salinity, diadromous fish have the ability to migrate between freshwater and saline water bodies. Many types of fish undertake migrations on a regular basis on time scales ranging from daily to annual and with distances ranging from a few meters to thousands of kilometers Fish are aquatic Vertebrate animals that are typically ectothermic (previously Cold-blooded) covered with scales, and equipped with two Many types of fish undertake migrations on a regular basis on time scales ranging from daily to annual and with distances ranging from a few meters to thousands of kilometers Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 During these migrations they undergo changes to adapt to the surroundings of the changed salinities; these processes are hormonally controlled. The eel (Anguilla anguilla) uses the hormone prolactin, while in salmon (Salmo salar) the hormone cortisol plays a key role during this process. Prolactin ( PRL) or Luteotropic hormone ( LTH) is a Peptide hormone primarily associated with Lactation. Cortisol is a Corticosteroid Hormone produced by the Adrenal gland (in the Zona fasciculata of the Adrenal cortex)
See also
References
- ^ Groundwater Glossary (2006-03-27). Desalination, desalinization, or desalinisation refers to any of several processes that remove excess salt and other Minerals from Water Limnology (from Greek Λίμνη limne, "lake" and λόγος logos, "knowledge" is the division of Hydrology that studies inland Seawater is Water from a Sea or Ocean. On average seawater in the world's oceans has a Salinity of about 3 Water ( H2[[oxygen O]] H OH) is the most abundant Molecule on Earth 's surface composing of about 70% of the Earth's surface as The Earth 's Water is always in movement and the water cycle, also known as the hydrologic cycle, describes the continuous movement of water on above Water resources are sources of Water that are useful or potentially useful to Humans Uses of water include Agricultural, industrial, Household Water Crisis is a term that refers to the status of the world’s Water resources relative to human demand Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 196 BC - Ptolemy V ascends to the throne of Egypt. 1309 - Pope Clement V excommunicates Retrieved on 2006-05-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the
- ^ Gleick, Peter; et al. (1996). in Stephen H. Schneider: Encyclopedia of Climate and Weather. Oxford University Press.
- ^ Vertebrate Kidneys (2002-11-03). See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar. Events 644 - Umar ibn al-Khattab, the second Muslim Caliph, is killed by a Persian slave in Medina. Retrieved on 2006-05-14. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1264 - Battle of Lewes: Henry III of England is captured in France making Simon de Montfort the
External links
- Freshwater life.org
- Freshwater Biological Association
- Review of freshwater ecology in the UK
- UK Government Environmental Agency website
- Pond Conservation
- UK National pond monitoring network
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