fbpx
Wikipedia

Fresh water

Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non-salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans.

Rivers, lakes, and marshlands, such as (from top) South America's Amazon River, Russia's Lake Baikal, and the Everglades in Florida of The United States, are types of freshwater systems.

Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive.

Fresh water is not always potable water, that is, water safe to drink by humans. Much of the earth's fresh water (on the surface and groundwater) is to a substantial degree unsuitable for human consumption without some treatment. Fresh water can easily become polluted by human activities or due to naturally occurring processes, such as erosion. Fresh water makes up less than 3% of the world's water resources, and just 1% of that is readily available. Just 3% of it is extracted for human consumption. Agriculture uses roughly two thirds of all fresh water abstracted from the environment.[1][2][3]

Fresh water is a renewable and variable, but finite natural resource. Fresh water is replenished through the process of the water cycle, in which water from seas, lakes, forests, land, rivers and reservoirs evaporates, forms clouds, and returns inland as precipitation.[4] Locally, however, if more fresh water is consumed through human activities than is naturally restored, this may result in reduced fresh water availability (or water scarcity) from surface and underground sources and can cause serious damage to surrounding and associated environments. Water pollution also reduces the availability of fresh water.

Definitions

Numerical definition

Fresh water can be defined as water with less than 500 parts per million (ppm) of dissolved salts.[5]

Other sources give higher upper salinity limits for fresh water, e.g. 1000 ppm[6] or 3000 ppm.[7]

Systems

Fresh water habitats are classified as either lentic systems, which are the stillwaters including ponds, lakes, swamps and mires; lotic which are running-water systems; or groundwaters which flow in rocks and aquifers. There is, in addition, a zone which bridges between groundwater and lotic systems, which is the hyporheic zone, which underlies many larger rivers and can contain substantially more water than is seen in the open channel. It may also be in direct contact with the underlying underground water.

Sources

The original source of almost all fresh water is precipitation from the atmosphere, in the form of mist, rain and snow. Fresh water falling as mist, rain or snow contains materials dissolved from the atmosphere and material from the sea and land over which the rain bearing clouds have traveled. The precipitation leads eventually to the formation of water bodies that humans can use as sources of freshwater: ponds, lakes, rainfall, rivers, streams, and groundwater contained in underground aquifers.

In coastal areas fresh water may contain significant concentrations of salts derived from the sea if windy conditions have lifted drops of seawater into the rain-bearing clouds. This can give rise to elevated concentrations of sodium, chloride, magnesium and sulfate as well as many other compounds in smaller concentrations.

In desert areas, or areas with impoverished or dusty soils, rain-bearing winds can pick up sand and dust and this can be deposited elsewhere in precipitation and causing the freshwater flow to be measurably contaminated both by insoluble solids but also by the soluble components of those soils. Significant quantities of iron may be transported in this way including the well-documented transfer of iron-rich rainfall falling in Brazil derived from sand-storms in the Sahara in north Africa.[citation needed]

Water distribution

 
Visualisation of the distribution (by volume) of water on Earth.[a]
 
A graphical distribution of the locations of water on Earth.[b]

Saline water in oceans, seas and saline groundwater make up about 97% of all the water on Earth. Only 2.5–2.75% is fresh water, including 1.75–2% frozen in glaciers, ice and snow, 0.5–0.75% as fresh groundwater and soil moisture, and less than 0.01% of it as surface water in lakes, swamps and rivers.[9][10] Freshwater lakes contain about 87% of this fresh surface water, including 29% in the African Great Lakes, 22% in Lake Baikal in Russia, 21% in the North American Great Lakes, and 14% in other lakes. Swamps have most of the balance with only a small amount in rivers, most notably the Amazon River. The atmosphere contains 0.04% water.[11] In areas with no fresh water on the ground surface, fresh water derived from precipitation may, because of its lower density, overlie saline ground water in lenses or layers. Most of the world's fresh water is frozen in ice sheets. Many areas have very little fresh water, such as deserts.

Freshwater ecosystems

Water is a critical issue for the survival of all living organisms. Some can use salt water but many organisms including the great majority of higher plants and most mammals must have access to fresh water to live. Some terrestrial mammals, especially desert rodents, appear to survive without drinking, but they do generate water through the metabolism of cereal seeds, and they also have mechanisms to conserve water to the maximum degree.

 
Freshwater ecosystem.

Freshwater ecosystems are a subset of Earth's aquatic ecosystems. They include lakes, ponds, rivers, streams, springs, bogs, and wetlands.[12] They can be contrasted with marine ecosystems, which have a larger salt content. Freshwater habitats can be classified by different factors, including temperature, light penetration, nutrients, and vegetation. There are three basic types of freshwater ecosystems: Lentic (slow moving water, including pools, ponds, and lakes), lotic (faster moving water, for example streams and rivers) and wetlands (areas where the soil is saturated or inundated for at least part of the time).[13][12] Freshwater ecosystems contain 41% of the world's known fish species.[14]

Freshwater ecosystems have undergone substantial transformations over time, which has impacted various characteristics of the ecosystems.[15] Original attempts to understand and monitor freshwater ecosystems were spurred on by threats to human health (for example cholera outbreaks due to sewage contamination).[16] Early monitoring focused on chemical indicators, then bacteria, and finally algae, fungi and protozoa. A new type of monitoring involves quantifying differing groups of organisms (macroinvertebrates, macrophytes and fish) and measuring the stream conditions associated with them.[17]

Challenges

The increase in the world population and the increase in per capita water use puts increasing strains on the finite resources availability of clean fresh water. The response by freshwater ecosystems to a changing climate can be described in terms of three interrelated components: water quality, water quantity or volume, and water timing. A change in one often leads to shifts in the others as well.[18]

Limited resource

Water scarcity (closely related to water stress or water crisis) is the lack of fresh water resources to meet the standard water demand. There are two types of water scarcity: physical or economic water scarcity. Physical water scarcity is where there is not enough water to meet all demands, including that needed for ecosystems to function effectively. Arid areas for example Central and West Asia, and North Africa often suffer from physical water scarcity.[19] On the other hand, economic water scarcity is caused by a lack of investment in infrastructure or technology to draw water from rivers, aquifers, or other water sources, or insufficient human capacity to satisfy the demand for water.[20] Much of Sub-Saharan Africa has economic water scarcity.[21]: 11 

The essence of global water scarcity is the geographic and temporal mismatch between fresh water demand and availability.[22][23] At the global level and on an annual basis, enough freshwater is available to meet such demand, but spatial and temporal variations of water demand and availability are large, leading to physical water scarcity in several parts of the world during specific times of the year.[24] The main driving forces for the rising global demand for water are the increasing world population, improving living standards, changing consumption patterns (for example a dietary shift toward more animal products),[25] and expansion of irrigated agriculture.[26][27] Climate change (including droughts or floods), deforestation, increased water pollution and wasteful use of water can also cause insufficient water supply.[28] Scarcity varies over time as a result of natural hydrological variability, but varies even more so as a function of prevailing economic policy, planning and management approaches. Scarcity can and will likely intensify with most forms of economic development, but many of its causes can be avoided or mitigated.[29]

Minimum streamflow

An important concern for hydrological ecosystems is securing minimum streamflow, especially preserving and restoring instream water allocations.[30] Fresh water is an important natural resource necessary for the survival of all ecosystems.

Water pollution

Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses.[31]: 6  Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. It can be attributed to one of four sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater.[32] It can be grouped into surface water pollution (either fresh water pollution or marine pollution) or groundwater pollution. For example, releasing inadequately treated wastewater into natural waters can lead to degradation of these aquatic ecosystems. Water pollution can also lead to water-borne diseases in people using polluted water for drinking, bathing, washing or irrigation.[33] Water pollution reduces the ability of the body of water to provide the ecosystem services (such as drinking water) that it would otherwise provide.

Sources of water pollution are either point sources or non-point sources. Point sources have one identifiable cause, such as a storm drain, a wastewater treatment plant or an oil spill. Non-point sources are more diffuse, such as agricultural runoff.[34] Pollution is the result of the cumulative effect over time. Pollution may take the form of toxic substances (e.g., oil, metals, plastics, pesticides, persistent organic pollutants, industrial waste products), stressful conditions (e.g., changes of pH, hypoxia or anoxia, increased temperatures, excessive turbidity, changes of salinity), or the introduction of pathogenic organisms. Contaminants may include organic and inorganic substances. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers.

Society and culture

Human uses

Uses of water include agricultural, industrial, household, recreational and environmental activities.

Global goals for conservation

The Sustainable Development Goals are a collection of 17 interlinked global goals designed to be a "blueprint to achieve a better and more sustainable future for all".[35] Targets on freshwater conservation are included in SDG 6 (Clean water and sanitation) and SDG 15 (Life on land). For example, Target 6.4 is formulated as "By 2030, substantially increase water-use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity and substantially reduce the number of people suffering from water scarcity."[35] Another target, Target 15.1, is: "By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular forests, wetlands, mountains and drylands, in line with obligations under international agreements."[35]

See also

Notes

  1. ^ Each tiny cube[i] (such as the one representing biological water) corresponds to approximately 1400 cubic km of water, with a mass of approximately 1.4 trillion tonnes (235000 times that of the Great Pyramid of Giza or 8 times that of Lake Kariba, arguably the heaviest man-made object).[8]
  2. ^ Only 3% of the Earth's water is fresh water. Most of it is in icecaps and glaciers (69%) and groundwater (30%), while all lakes, rivers and swamps combined only account for a small fraction (0.3%) of the Earth's total freshwater reserves.[citation needed]

Subnotes

  1. ^ The entire block comprises 1 million tiny cubes.

References

  1. ^ "Wastewater resource recovery can fix water insecurity and cut carbon emissions". European Investment Bank. Retrieved 29 August 2022.
  2. ^ "Competing for Clean Water Has Led to a Crisis". Environment. 26 January 2010. Retrieved 29 August 2022.
  3. ^ "Freshwater Resources | National Geographic Society". education.nationalgeographic.org. Retrieved 29 August 2022.
  4. ^ "The Fundamentals of the Water Cycle". www.usgs.gov. Retrieved 17 September 2021.
  5. ^ . 27 March 2006. Archived from the original on 28 April 2006. Retrieved 14 May 2006.
  6. ^ . Glossary of Meteorology. American Meteorological Society. June 2000. Archived from the original on 6 June 2011. Retrieved 27 November 2009.
  7. ^ . Fishkeeping glossary. Practical Fishkeeping. Archived from the original on 11 May 2006. Retrieved 27 November 2009.
  8. ^ USGS – Earth's water distribution 29 June 2012 at the Wayback Machine. Ga.water.usgs.gov (11 December 2012). Retrieved on 29 December 2012.
  9. ^ Where is Earth's water? 14 December 2013 at the Wayback Machine, United States Geological Survey.
  10. ^ Physicalgeography.net 26 January 2016 at the Wayback Machine. Physicalgeography.net. Retrieved on 29 December 2012.
  11. ^ Gleick, Peter; et al. (1996). Stephen H. Schneider (ed.). Encyclopedia of Climate and Weather. Oxford University Press.
  12. ^ a b G., Wetzel, Robert (2001). Limnology : lake and river ecosystems (3rd ed.). San Diego: Academic Press. ISBN 978-0127447605. OCLC 46393244.
  13. ^ Vaccari, David A. (8 November 2005). Environmental Biology for Engineers and Scientists. Wiley-Interscience. ISBN 0-471-74178-7.
  14. ^ Daily, Gretchen C. (1 February 1997). Nature's Services. Island Press. ISBN 1-55963-476-6.
  15. ^ Carpenter, Stephen R.; Stanley, Emily H.; Vander Zanden, M. Jake (2011). "State of the World's Freshwater Ecosystems: Physical, Chemical, and Biological Changes". Annual Review of Environment and Resources. 36 (1): 75–99. doi:10.1146/annurev-environ-021810-094524. ISSN 1543-5938.
  16. ^ Rudolfs, Willem; Falk, Lloyd L.; Ragotzkie, R. A. (1950). "Literature Review on the Occurrence and Survival of Enteric, Pathogenic, and Relative Organisms in Soil, Water, Sewage, and Sludges, and on Vegetation: I. Bacterial and Virus Diseases". Sewage and Industrial Wastes. 22 (10): 1261–1281. JSTOR 25031419.
  17. ^ Friberg, Nikolai; Bonada, Núria; Bradley, David C.; Dunbar, Michael J.; Edwards, Francois K.; Grey, Jonathan; Hayes, Richard B.; Hildrew, Alan G.; Lamouroux, Nicolas (2011), "Biomonitoring of Human Impacts in Freshwater Ecosystems", Advances in Ecological Research, Elsevier, pp. 1–68, doi:10.1016/b978-0-12-374794-5.00001-8, ISBN 9780123747945
  18. ^ The World Bank, 2009 . pp. 19–22. Archived from the original on 7 April 2012. Retrieved 24 October 2011.
  19. ^ Rijsberman, Frank R. (2006). "Water scarcity: Fact or fiction?". Agricultural Water Management. 80 (1–3): 5–22. doi:10.1016/j.agwat.2005.07.001.
  20. ^ "Climate Change 2022 Impacts, Adaptation and Vulnerability" (PDF). IPCC Sixth Assessment Report. 27 February 2022. Retrieved 1 March 2022.
  21. ^ "Wastewater resource recovery can fix water insecurity and cut carbon emissions". European Investment Bank. Retrieved 29 August 2022.
  22. ^ S. L. Postel, G. C. Daily, P. R. Ehrlich, Human appropriation of renewable fresh water. Science 271, 785–788 (1996).https://www.science.org/doi/10.1126/science.271.5250.785
  23. ^ H. H. G. Savenije, Water scarcity indicators; the deception of the numbers. Physics and Chemistry of the Earth B 25, 199–204 (2000).
  24. ^ Mekonnen, Mesfin M.; Hoekstra, Arjen Y. (2016). "Four billion people facing severe water scarcity". Science Water Stress Advances. 2 (2): e1500323. Bibcode:2016SciA....2E0323M. doi:10.1126/sciadv.1500323. ISSN 2375-2548. PMC 4758739. PMID 26933676.
  25. ^ Liu, Junguo; Yang, Hong; Gosling, Simon N.; Kummu, Matti; Flörke, Martina; Pfister, Stephan; Hanasaki, Naota; Wada, Yoshihide; Zhang, Xinxin; Zheng, Chunmiao; Alcamo, Joseph (2017). "Water scarcity assessments in the past, present, and future: Review on Water Scarcity Assessment". Earth's Future. 5 (6): 545–559. doi:10.1002/2016EF000518. PMC 6204262. PMID 30377623.
  26. ^ Vorosmarty, C. J. (14 July 2000). "Global Water Resources: Vulnerability from Climate Change and Population Growth". Science. 289 (5477): 284–288. Bibcode:2000Sci...289..284V. doi:10.1126/science.289.5477.284. PMID 10894773. S2CID 37062764.
  27. ^ Ercin, A. Ertug; Hoekstra, Arjen Y. (2014). "Water footprint scenarios for 2050: A global analysis". Environment International. 64: 71–82. doi:10.1016/j.envint.2013.11.019. PMID 24374780.
  28. ^ "Water Scarcity. Threats". WWF. 2013. from the original on 21 October 2013. Retrieved 20 October 2013.
  29. ^ "Coping with water scarcity. An action framework for agriculture and food stress" (PDF). Food and Agriculture Organization of the United Nations. 2012. (PDF) from the original on 4 March 2018. Retrieved 31 December 2017. Text was copied from this source, which is available under a Creative Commons Attribution 3.0 IGO (CC BY 3.0 IGO) license.
  30. ^ Peter Gleick; Heather Cooley; David Katz (2006). The world's water, 2006–2007: the biennial report on freshwater resources. Island Press. pp. 29–31. ISBN 978-1-59726-106-7. Retrieved 12 September 2009.
  31. ^ Von Sperling, Marcos (2015). "Wastewater Characteristics, Treatment and Disposal". IWA Publishing. 6. doi:10.2166/9781780402086. ISBN 9781780402086. from the original on 21 June 2022. Retrieved 26 September 2022.
  32. ^ Eckenfelder Jr WW (2000). Kirk‐Othmer Encyclopedia of Chemical Technology. John Wiley & Sons. doi:10.1002/0471238961.1615121205031105.a01. ISBN 978-0-471-48494-3.
  33. ^ "Water Pollution". Environmental Health Education Program. Cambridge, MA: Harvard T.H. Chan School of Public Health. 23 July 2013. from the original on 18 September 2021. Retrieved 18 September 2021.
  34. ^ Moss B (February 2008). "Water pollution by agriculture". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 363 (1491): 659–666. doi:10.1098/rstb.2007.2176. PMC 2610176. PMID 17666391.
  35. ^ a b c United Nations (2017) Resolution adopted by the General Assembly on 6 July 2017, Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development (A/RES/71/313)

External links

  • The World Bank's work and publications on water resources
  • U.S. Geological Survey 6 August 2012 at the Wayback Machine
  • Fresh Water National Geographic 27 November 2016 at the Wayback Machine

fresh, water, this, article, about, naturally, occurring, type, water, types, waters, that, potential, humans, water, resources, other, uses, freshwater, disambiguation, this, section, needs, additional, citations, verification, please, help, improve, this, ar. This article is about a naturally occurring type of water For all types of waters that are of potential use to humans see water resources For other uses see Freshwater disambiguation This section needs additional citations for verification Please help improve this article by adding citations to reliable sources Unsourced material may be challenged and removed November 2022 Learn how and when to remove this template message Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids Although the term specifically excludes seawater and brackish water it does include non salty mineral rich waters such as chalybeate springs Fresh water may encompass frozen and meltwater in ice sheets ice caps glaciers snowfields and icebergs natural precipitations such as rainfall snowfall hail sleet and graupel and surface runoffs that form inland bodies of water such as wetlands ponds lakes rivers streams as well as groundwater contained in aquifers subterranean rivers and lakes Fresh water is the water resource that is of the most and immediate use to humans Rivers lakes and marshlands such as from top South America s Amazon River Russia s Lake Baikal and the Everglades in Florida of The United States are types of freshwater systems Water is critical to the survival of all living organisms Many organisms can thrive on salt water but the great majority of higher plants and most insects amphibians reptiles mammals and birds need fresh water to survive Fresh water is not always potable water that is water safe to drink by humans Much of the earth s fresh water on the surface and groundwater is to a substantial degree unsuitable for human consumption without some treatment Fresh water can easily become polluted by human activities or due to naturally occurring processes such as erosion Fresh water makes up less than 3 of the world s water resources and just 1 of that is readily available Just 3 of it is extracted for human consumption Agriculture uses roughly two thirds of all fresh water abstracted from the environment 1 2 3 Fresh water is a renewable and variable but finite natural resource Fresh water is replenished through the process of the water cycle in which water from seas lakes forests land rivers and reservoirs evaporates forms clouds and returns inland as precipitation 4 Locally however if more fresh water is consumed through human activities than is naturally restored this may result in reduced fresh water availability or water scarcity from surface and underground sources and can cause serious damage to surrounding and associated environments Water pollution also reduces the availability of fresh water Contents 1 Definitions 1 1 Numerical definition 1 2 Systems 2 Sources 3 Water distribution 4 Freshwater ecosystems 5 Challenges 5 1 Limited resource 5 2 Minimum streamflow 5 3 Water pollution 6 Society and culture 6 1 Human uses 6 2 Global goals for conservation 7 See also 8 Notes 9 References 10 External linksDefinitions EditNumerical definition Edit Fresh water can be defined as water with less than 500 parts per million ppm of dissolved salts 5 Other sources give higher upper salinity limits for fresh water e g 1000 ppm 6 or 3000 ppm 7 Systems Edit Fresh water habitats are classified as either lentic systems which are the stillwaters including ponds lakes swamps and mires lotic which are running water systems or groundwaters which flow in rocks and aquifers There is in addition a zone which bridges between groundwater and lotic systems which is the hyporheic zone which underlies many larger rivers and can contain substantially more water than is seen in the open channel It may also be in direct contact with the underlying underground water Sources EditMain articles Water cycle and Water resources The original source of almost all fresh water is precipitation from the atmosphere in the form of mist rain and snow Fresh water falling as mist rain or snow contains materials dissolved from the atmosphere and material from the sea and land over which the rain bearing clouds have traveled The precipitation leads eventually to the formation of water bodies that humans can use as sources of freshwater ponds lakes rainfall rivers streams and groundwater contained in underground aquifers In coastal areas fresh water may contain significant concentrations of salts derived from the sea if windy conditions have lifted drops of seawater into the rain bearing clouds This can give rise to elevated concentrations of sodium chloride magnesium and sulfate as well as many other compounds in smaller concentrations In desert areas or areas with impoverished or dusty soils rain bearing winds can pick up sand and dust and this can be deposited elsewhere in precipitation and causing the freshwater flow to be measurably contaminated both by insoluble solids but also by the soluble components of those soils Significant quantities of iron may be transported in this way including the well documented transfer of iron rich rainfall falling in Brazil derived from sand storms in the Sahara in north Africa citation needed Water distribution Edit Visualisation of the distribution by volume of water on Earth a A graphical distribution of the locations of water on Earth b Main article Water distribution on Earth Saline water in oceans seas and saline groundwater make up about 97 of all the water on Earth Only 2 5 2 75 is fresh water including 1 75 2 frozen in glaciers ice and snow 0 5 0 75 as fresh groundwater and soil moisture and less than 0 01 of it as surface water in lakes swamps and rivers 9 10 Freshwater lakes contain about 87 of this fresh surface water including 29 in the African Great Lakes 22 in Lake Baikal in Russia 21 in the North American Great Lakes and 14 in other lakes Swamps have most of the balance with only a small amount in rivers most notably the Amazon River The atmosphere contains 0 04 water 11 In areas with no fresh water on the ground surface fresh water derived from precipitation may because of its lower density overlie saline ground water in lenses or layers Most of the world s fresh water is frozen in ice sheets Many areas have very little fresh water such as deserts Freshwater ecosystems EditWater is a critical issue for the survival of all living organisms Some can use salt water but many organisms including the great majority of higher plants and most mammals must have access to fresh water to live Some terrestrial mammals especially desert rodents appear to survive without drinking but they do generate water through the metabolism of cereal seeds and they also have mechanisms to conserve water to the maximum degree This section is an excerpt from Freshwater ecosystem edit Freshwater ecosystem Freshwater ecosystems are a subset of Earth s aquatic ecosystems They include lakes ponds rivers streams springs bogs and wetlands 12 They can be contrasted with marine ecosystems which have a larger salt content Freshwater habitats can be classified by different factors including temperature light penetration nutrients and vegetation There are three basic types of freshwater ecosystems Lentic slow moving water including pools ponds and lakes lotic faster moving water for example streams and rivers and wetlands areas where the soil is saturated or inundated for at least part of the time 13 12 Freshwater ecosystems contain 41 of the world s known fish species 14 Freshwater ecosystems have undergone substantial transformations over time which has impacted various characteristics of the ecosystems 15 Original attempts to understand and monitor freshwater ecosystems were spurred on by threats to human health for example cholera outbreaks due to sewage contamination 16 Early monitoring focused on chemical indicators then bacteria and finally algae fungi and protozoa A new type of monitoring involves quantifying differing groups of organisms macroinvertebrates macrophytes and fish and measuring the stream conditions associated with them 17 Challenges EditMain article Water resources Challenges and threats Further information Human impacts on the environment and Freshwater ecosystem Threats The increase in the world population and the increase in per capita water use puts increasing strains on the finite resources availability of clean fresh water The response by freshwater ecosystems to a changing climate can be described in terms of three interrelated components water quality water quantity or volume and water timing A change in one often leads to shifts in the others as well 18 Limited resource Edit This section is an excerpt from Water scarcity edit Water scarcity closely related to water stress or water crisis is the lack of fresh water resources to meet the standard water demand There are two types of water scarcity physical or economic water scarcity Physical water scarcity is where there is not enough water to meet all demands including that needed for ecosystems to function effectively Arid areas for example Central and West Asia and North Africa often suffer from physical water scarcity 19 On the other hand economic water scarcity is caused by a lack of investment in infrastructure or technology to draw water from rivers aquifers or other water sources or insufficient human capacity to satisfy the demand for water 20 Much of Sub Saharan Africa has economic water scarcity 21 11 The essence of global water scarcity is the geographic and temporal mismatch between fresh water demand and availability 22 23 At the global level and on an annual basis enough freshwater is available to meet such demand but spatial and temporal variations of water demand and availability are large leading to physical water scarcity in several parts of the world during specific times of the year 24 The main driving forces for the rising global demand for water are the increasing world population improving living standards changing consumption patterns for example a dietary shift toward more animal products 25 and expansion of irrigated agriculture 26 27 Climate change including droughts or floods deforestation increased water pollution and wasteful use of water can also cause insufficient water supply 28 Scarcity varies over time as a result of natural hydrological variability but varies even more so as a function of prevailing economic policy planning and management approaches Scarcity can and will likely intensify with most forms of economic development but many of its causes can be avoided or mitigated 29 Minimum streamflow Edit Further information Water scarcity Environment An important concern for hydrological ecosystems is securing minimum streamflow especially preserving and restoring instream water allocations 30 Fresh water is an important natural resource necessary for the survival of all ecosystems Water pollution Edit This section is an excerpt from Water pollution edit Water pollution or aquatic pollution is the contamination of water bodies usually as a result of human activities so that it negatively affects its uses 31 6 Water bodies include lakes rivers oceans aquifers reservoirs and groundwater Water pollution results when contaminants are introduced into these water bodies It can be attributed to one of four sources sewage discharges industrial activities agricultural activities and urban runoff including stormwater 32 It can be grouped into surface water pollution either fresh water pollution or marine pollution or groundwater pollution For example releasing inadequately treated wastewater into natural waters can lead to degradation of these aquatic ecosystems Water pollution can also lead to water borne diseases in people using polluted water for drinking bathing washing or irrigation 33 Water pollution reduces the ability of the body of water to provide the ecosystem services such as drinking water that it would otherwise provide Sources of water pollution are either point sources or non point sources Point sources have one identifiable cause such as a storm drain a wastewater treatment plant or an oil spill Non point sources are more diffuse such as agricultural runoff 34 Pollution is the result of the cumulative effect over time Pollution may take the form of toxic substances e g oil metals plastics pesticides persistent organic pollutants industrial waste products stressful conditions e g changes of pH hypoxia or anoxia increased temperatures excessive turbidity changes of salinity or the introduction of pathogenic organisms Contaminants may include organic and inorganic substances A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers Society and culture EditHuman uses Edit Main article Water resources Water uses Uses of water include agricultural industrial household recreational and environmental activities Global goals for conservation Edit The Sustainable Development Goals are a collection of 17 interlinked global goals designed to be a blueprint to achieve a better and more sustainable future for all 35 Targets on freshwater conservation are included in SDG 6 Clean water and sanitation and SDG 15 Life on land For example Target 6 4 is formulated as By 2030 substantially increase water use efficiency across all sectors and ensure sustainable withdrawals and supply of freshwater to address water scarcity and substantially reduce the number of people suffering from water scarcity 35 Another target Target 15 1 is By 2020 ensure the conservation restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services in particular forests wetlands mountains and drylands in line with obligations under international agreements 35 See also EditLimnology Science of inland aquatic ecosystems Properties of water Physical and chemical properties of pure waterNotes Edit Each tiny cube i such as the one representing biological water corresponds to approximately 1400 cubic km of water with a mass of approximately 1 4 trillion tonnes 235000 times that of the Great Pyramid of Giza or 8 times that of Lake Kariba arguably the heaviest man made object 8 Only 3 of the Earth s water is fresh water Most of it is in icecaps and glaciers 69 and groundwater 30 while all lakes rivers and swamps combined only account for a small fraction 0 3 of the Earth s total freshwater reserves citation needed Subnotes The entire block comprises 1 million tiny cubes References Edit Wastewater resource recovery can fix water insecurity and cut carbon emissions European Investment Bank Retrieved 29 August 2022 Competing for Clean Water Has Led to a Crisis Environment 26 January 2010 Retrieved 29 August 2022 Freshwater Resources National Geographic Society education nationalgeographic org Retrieved 29 August 2022 The Fundamentals of the Water Cycle www usgs gov Retrieved 17 September 2021 Groundwater Glossary 27 March 2006 Archived from the original on 28 April 2006 Retrieved 14 May 2006 Freshwater Glossary of Meteorology American Meteorological Society June 2000 Archived from the original on 6 June 2011 Retrieved 27 November 2009 Freshwater Fishkeeping glossary Practical Fishkeeping Archived from the original on 11 May 2006 Retrieved 27 November 2009 USGS Earth s water distribution Archived 29 June 2012 at the Wayback Machine Ga water usgs gov 11 December 2012 Retrieved on 29 December 2012 Where is Earth s water Archived 14 December 2013 at the Wayback Machine United States Geological Survey Physicalgeography net Archived 26 January 2016 at the Wayback Machine Physicalgeography net Retrieved on 29 December 2012 Gleick Peter et al 1996 Stephen H Schneider ed Encyclopedia of Climate and Weather Oxford University Press a b G Wetzel Robert 2001 Limnology lake and river ecosystems 3rd ed San Diego Academic Press ISBN 978 0127447605 OCLC 46393244 Vaccari David A 8 November 2005 Environmental Biology for Engineers and Scientists Wiley Interscience ISBN 0 471 74178 7 Daily Gretchen C 1 February 1997 Nature s Services Island Press ISBN 1 55963 476 6 Carpenter Stephen R Stanley Emily H Vander Zanden M Jake 2011 State of the World s Freshwater Ecosystems Physical Chemical and Biological Changes Annual Review of Environment and Resources 36 1 75 99 doi 10 1146 annurev environ 021810 094524 ISSN 1543 5938 Rudolfs Willem Falk Lloyd L Ragotzkie R A 1950 Literature Review on the Occurrence and Survival of Enteric Pathogenic and Relative Organisms in Soil Water Sewage and Sludges and on Vegetation I Bacterial and Virus Diseases Sewage and Industrial Wastes 22 10 1261 1281 JSTOR 25031419 Friberg Nikolai Bonada Nuria Bradley David C Dunbar Michael J Edwards Francois K Grey Jonathan Hayes Richard B Hildrew Alan G Lamouroux Nicolas 2011 Biomonitoring of Human Impacts in Freshwater Ecosystems Advances in Ecological Research Elsevier pp 1 68 doi 10 1016 b978 0 12 374794 5 00001 8 ISBN 9780123747945 The World Bank 2009 Water and Climate Change Understanding the Risks and Making Climate Smart Investment Decisions pp 19 22 Archived from the original on 7 April 2012 Retrieved 24 October 2011 Rijsberman Frank R 2006 Water scarcity Fact or fiction Agricultural Water Management 80 1 3 5 22 doi 10 1016 j agwat 2005 07 001 Climate Change 2022 Impacts Adaptation and Vulnerability PDF IPCC Sixth Assessment Report 27 February 2022 Retrieved 1 March 2022 Wastewater resource recovery can fix water insecurity and cut carbon emissions European Investment Bank Retrieved 29 August 2022 S L Postel G C Daily P R Ehrlich Human appropriation of renewable fresh water Science 271 785 788 1996 https www science org doi 10 1126 science 271 5250 785 H H G Savenije Water scarcity indicators the deception of the numbers Physics and Chemistry of the Earth B 25 199 204 2000 Mekonnen Mesfin M Hoekstra Arjen Y 2016 Four billion people facing severe water scarcity Science Water Stress Advances 2 2 e1500323 Bibcode 2016SciA 2E0323M doi 10 1126 sciadv 1500323 ISSN 2375 2548 PMC 4758739 PMID 26933676 Liu Junguo Yang Hong Gosling Simon N Kummu Matti Florke Martina Pfister Stephan Hanasaki Naota Wada Yoshihide Zhang Xinxin Zheng Chunmiao Alcamo Joseph 2017 Water scarcity assessments in the past present and future Review on Water Scarcity Assessment Earth s Future 5 6 545 559 doi 10 1002 2016EF000518 PMC 6204262 PMID 30377623 Vorosmarty C J 14 July 2000 Global Water Resources Vulnerability from Climate Change and Population Growth Science 289 5477 284 288 Bibcode 2000Sci 289 284V doi 10 1126 science 289 5477 284 PMID 10894773 S2CID 37062764 Ercin A Ertug Hoekstra Arjen Y 2014 Water footprint scenarios for 2050 A global analysis Environment International 64 71 82 doi 10 1016 j envint 2013 11 019 PMID 24374780 Water Scarcity Threats WWF 2013 Archived from the original on 21 October 2013 Retrieved 20 October 2013 Coping with water scarcity An action framework for agriculture and food stress PDF Food and Agriculture Organization of the United Nations 2012 Archived PDF from the original on 4 March 2018 Retrieved 31 December 2017 Text was copied from this source which is available under a Creative Commons Attribution 3 0 IGO CC BY 3 0 IGO license Peter Gleick Heather Cooley David Katz 2006 The world s water 2006 2007 the biennial report on freshwater resources Island Press pp 29 31 ISBN 978 1 59726 106 7 Retrieved 12 September 2009 Von Sperling Marcos 2015 Wastewater Characteristics Treatment and Disposal IWA Publishing 6 doi 10 2166 9781780402086 ISBN 9781780402086 Archived from the original on 21 June 2022 Retrieved 26 September 2022 Eckenfelder Jr WW 2000 Kirk Othmer Encyclopedia of Chemical Technology John Wiley amp Sons doi 10 1002 0471238961 1615121205031105 a01 ISBN 978 0 471 48494 3 Water Pollution Environmental Health Education Program Cambridge MA Harvard T H Chan School of Public Health 23 July 2013 Archived from the original on 18 September 2021 Retrieved 18 September 2021 Moss B February 2008 Water pollution by agriculture Philosophical Transactions of the Royal Society of London Series B Biological Sciences 363 1491 659 666 doi 10 1098 rstb 2007 2176 PMC 2610176 PMID 17666391 a b c United Nations 2017 Resolution adopted by the General Assembly on 6 July 2017 Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development A RES 71 313 External links Edit Wikimedia Commons has media related to Freshwater The World Bank s work and publications on water resources U S Geological Survey Archived 6 August 2012 at the Wayback Machine Fresh Water National Geographic Archived 27 November 2016 at the Wayback Machine Retrieved from https en wikipedia org w index php title Fresh water amp oldid 1131964292, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.