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[[ImageBerkas:LagoBariloche- SariqamishArgentina2.jpg|thumbjmpl|240px|[[Danau SarygamyshNahuel Huapi]] di [[TurkmenistanBariloche]], dilihat melalui [[satelitArgentina]].]]
[[Berkas:Lago Sariqamish.jpg|jmpl|240px|[[Danau Sarygamysh]] di [[Turkmenistan]], dilihat melalui [[satelit]].]]
'''Danau''' ({{lang-en|lake}}, {{lang-ms|tasik}}; {{lang-su|''situ''}}; {{lang-jv|''Ranu,tlaga''}}; [[bahasa Batak]]: ''tao'') adalah daerah perairan yang terbentuk secara alami, berupa basin air yang sangat luas.<ref>{{cite journal|title= Kerusakan Danau Limboto dan Upaya Konservasi Melalui Pemberdayaan Masyarakat dan Peran Perguruan Tinggi|author= Elya Nusantari|journal= Jurnal Pendidikan Biologi|volume= 1|number= 2|year= 2010|issn= 2085-6873|page= 1|url= https://repository.ung.ac.id/karyailmiah/show/1519/kerusakan-danau-limboto-dan-upaya-konservasi-melalui-pemberdayaan-masyarakat-dan-peran-perguruan-tinggi.html}}</ref> Danau adalah cekungan besar di permukaan bumi yang digenangi oleh air bisa tawar ataupun asin yang seluruh cekungan tersebut dikelilingi oleh daratan.<ref name=":0">{{Cite news|last=Nailufar|first=Nibras Nada|title=Pengertian dan Fungsi Danau|url=https://www.kompas.com/skola/read/2020/04/06/060000269/pengertian-dan-fungsi-danau|work=[[Kompas.com]]|language=id|access-date=2020-12-19|editor-last=Nailufar|editor-first=Nibras Nada}}</ref>
'''Danau''' adalah sejumlah [[air]] (tawar atau asin) yang terakumulasi di suatu tempat yang cukup luas, yang dapat terjadi karena mencairnya [[gletser]], aliran sungai, atau karena adanya mata air. Biasanya danau dapat dipakai sebagai sarana rekreasi, dan olahraga.
Danau rata-rata memiliki kedalaman yang dangkal dan airnya berasal dari berbagai macam sumber seperti mata air, air tanah, air sungai, dan air hujan.<ref name=":0" /> Kebanyakan danau adalah [[air tawar]] dan juga banyak berada di belahan bumi utara pada ketinggian yang lebih atas. Sebuah danau [[periglasial]] adalah danau yang di salah satunya terbentuk [[lapisan es]], atau [[gletser]], es ini menutupi aliran air keluar danau.
Istilah danau juga digunakan untuk menggambarkan fenomena seperti [[Danau Eyre]], di mana danau ini kering di banyak waktu dan hanya terisi pada saat musim hujan. Banyak danau adalah buatan dan sengaja dibangun untuk penyediaan tenaga [[listrik-hidro]], [[rekreasi]] ([[berenang]], [[selancar angin]], dan lain-lain), persediaan air, dan lain-lain. [[Finlandia]] dikenal sebagai "Tanah Seribu Danau" dan [[Minnesota]] dikenal sebagai "Tanah Sepuluh Ribu Danau". ''[[Great Lakes]]'' di [[Amerika Utara]] juga memiliki asal dari [[zaman es]]. Sekitar 60% danau dunia terletak di [[Kanada]]; ini dikarenakan sistem pengaliran kacau yang mendominasi negara ini.
Sebuah danau [[periglasial]] adalah danau yang di salah satunya terbentuk [[lapisan es]], "[[ice cap]]" atau gletser, es ini menutupi aliran air keluar danau.
Istilah danau juga digunakan untuk menggambarkan fenomena seperti [[Danau Eyre]], di mana danau ini kering di banyak waktu dan hanya terisi pada saat musim hujan. Banyak danau adalah buatan dan sengaja dibangun untuk penyediaan tenaga [[listrik-hidro]], [[rekreasi]] ([[berenang]], [[selancar angin]], dll), persediaan air, dll.
[[Finlandia]] dikenal sebagai "Tanah Seribu Danau" dan [[Minnesota]] dikenal sebagai "Tanah Sepuluh Ribu Danau". ''[[Great Lakes]]'' di [[Amerika Utara]] juga memiliki asal dari [[jaman es]]. Sekitar 60% danau dunia terletak di [[Kanada]]; ini dikarenakan sistem pengaliran kacau yang mendominasi negara ini.
Di [[bulan]] ada wilayah gelap berbasal, mirip [[mare bulan]] tetapi lebih kecil, yang disebut ''lacus'' (dari [[bahasa Latin]] yang berarti "danau"). Mereka diperkirakan oleh para astronom sebagai danau.
Danau merupakan salah satu bentuk [[ekosistem]] yang menempati suatu wilayah yang relatif kecil pada permukaan bumi. Wilayah yang ditempati suatu danau lebih kecil dibandingkan dengan [[laut]] dan [[daratan]]. Danau memberikan dampak yang positif bagi masyakat yang tinggal disekitaran wilayah danau.<ref>{{Cite journal|last=Asnil, dkk.|first=|date=2013|title=Analisis Kebijakan Pemanfaatan Sumberdaya Danau Yang Berkelanjutan (Studi Kasus Danau Maninjau Sumatera Barat)|url=https://media.neliti.com/media/publications/123866-ID-analisis-kebijakan-pemanfaatan-sumberday.pdf|journal=Jurnal Pengelolaan Sumberdaya Alam dan Lingkungan|volume=3|issue=1|pages=1|doi=}}</ref>
== Danau terkenal ==
[[Berkas:Danau Toba.jpg|240px|thumb|[[Danau Toba]] di [[Sumatra]], [[Indonesia]].]]
* Danau terbesar di dunia adalah [[Laut Kaspia]]. Dengan luas permukaan 394.299 [[kilometer persegi|km²]], ia memiliki wilayah yang lebih besar dari enam danau terbesar berikut digabungkan menjadi satu.
* Danau air tawar terbesar, dan kedua terbesar adalah [[Danau Superior]] dengan luas permukaan 82.414 km².
* Danau terdalam adalah [[Danau Baikal]] di [[Siberia]], dengan kedalaman 1.741 [[meter]] (5.712 [[kaki]]).
* Danau tertinggi yang dapat dinavigasi adalah Danau [[Titicaca]], pada ketinggian 3.821 m di atas permukaan laut. Dia juga merupakan danau terbesar kedua di [[Amerika Selatan]].
* Danau terendah di dunia adalah [[Laut Mati]], pada 396 m (1.302 kaki) di bawah permukaan laut. Dia juga merupakan danau yang memiliki konsentrasi [[garam]] paling tinggi.
* Pulau terbesar di tengah danau air tawar adalah [[Pulau Manitoulin]] di [[Danau Huron]], dengan luas permukaan 2.766 km².
* Danau terbesar yang terletak di pulau adalah Danau Nettiling di [[Pulau Baffin]].
* [[Danau Toba]] di pulau [[Sumatra]] kemungkinan terletak di kawah gunung berapi pasif terbesar di dunia.
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==Origin of natural lakes==
Most lakes are young, as the natural results of erosion will tend to wear away one of the basin sides containing the lake. There are a number of natural processes that can form lakes. A recent [[tectonic]] uplift of a mountain range can create bowl-shaped depressions that accumulate water and form lakes. The advance and retreat of glaciers can scrape depressions in the surface where lakes accumulate. Such lakes are common in [[Scandinavia]], [[Siberia]] and [[Canada]].
== Jenis ==
Lakes can also form by means of landslides or by glacial blockages. An example of the later occurred during the last ice age in the state of [[Washington]], when a huge lake formed behind a glacial flow. When the ice retreated, the result was an immense flood that created the Dry Falls monument at Sun Lakes, Washington.
{{tanpa referensi}}
=== Danau tektonik ===
Saline lakes can form where there is no natural outlet or the water evaporates rapidly, and the drainage surface of the water table has a higher than normal [[salt]] content. Examples of salt lakes include the [[Great Salt Lake]], the [[Caspian Sea]] and the [[Dead Sea]].
[[Danau tektonik]] yaitu danau yang terbentuk akibat penurunan muka bumi karena pergeseran/patahan.<ref name=":1">{{Cite web|last=Media|first=Kompas Cyber|date=2020-04-06|title=Jenis-jenis Danau Berdasarkan Proses Terbentuknya Halaman all|url=https://www.kompas.com/skola/read/2020/04/06/080000569/jenis-jenis-danau-berdasarkan-proses-terbentuknya|website=KOMPAS.com|language=id|access-date=2023-06-20}}</ref>
=== Danau vulkanik ===
Small, crescent-shaped lakes called [[oxbow lake]]s can form in river valleys as the result of meandering. The slow-moving river forms a sinuous shape as the outer side of bends is worn away more rapidly than the inner side. Eventually a horseshoe bend is formed and the river cuts through the narrow neck. This gap now forms the main passage for the river and the ends of the bend become silted up.
[[Danau vulkanik]] yaitu danau yang terbentuk akibat aktivitas [[vulkanisme]]/ gunung berapi.<ref name=":1" />
=== Danau tektovulkanik ===
[[Lake Vostok]] is an under-ice lake in [[Antarctica]], possibly the largest in the world. The pressure from ice and the internal chemical composition means that if the lake were drilled into, it may result in a fissure and spraying in the same manner as a shaken can of soda.
[[Danau tektovulkanik]] yaitu danau yang terbentuk akibat percampuran aktivitas [[tektonisme]] dan [[vulkanisme]].<ref name=":1" />
=== Danau karst ===
Some lakes, like Lake Baikal and [[Lake Tanganyika]] are volcanic in origin, and lie on [[geological fault]] lines. The [[Crater Lake]] in [[Oregon]] is a lake located within the [[caldera]] of an extinct volcano.
[[Danau karst]] atau lokva adalah danau yang terbentuk akibat terjadinya [[erosi]] atau [[pelarutan]] pada [[Gamping|batu gamping]]. Pembentukan danau karst hanya terjadi di daerah dengan jumlah batu gamping yang berlimpah. Cekungan terbentuk di bekas batu gamping yang mengalami erosi. Setelahnya, cekungan terisi air dan membentuk danau. Danau karst banyak terbentuk di [[Kabupaten Gunungkidul]] dan Pegunungan Batugamping di [[Kabupaten Kutai Timur]].<ref>{{Cite book|last=Kasnowihardjo|first=H. Gunadi|date=2017|url=https://e-service.lipipress.lipi.go.id/press/catalog/download/255/236/629-1?inline=1|title=Manusia dan Ranu: Kajian Arkeologi Permukiman|location=Yogyakarta|publisher=Kepel Press|isbn=978-602-356-150-6|pages=8|url-status=live}}{{Pranala mati|date=Januari 2023 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
=== Danau glasial ===
==Artificial lakes==
[[Danau glasial]] Danau glasial terbentuk akibat pengikiran dasar lembah oleh gletser. Ketika musim panas atau musim gugur, gletser yang mencair mengisi cekungan-cekungan yang dilewati sehingga membentuk danau.<ref name=":1" />
A [[reservoir]] ([[French language|French]]: ''réservoir'') is an artificial lake created by flooding land behind a [[dam]]. Some of the world's largest lakes are reservoirs. Artificial lakes can also be made deliberately by digging one or by flooding an open-pit [[Mining|mine]].
=== Danau tapal kuda ===
To build dams, surveyors have to find river valleys which are deep and narrow; the valley sides can then act as natural walls. The best place for building a dam has to be determined. If necessary, humans have to be re-housed and/or historic sites have to be moved, e.g. the temples of [[Abu Simbel]] before the construction of the [[Aswan Dam]], creating [[Lake Nasser]].
'''[[Danau tapal kuda]]''' (disebut pula '''danau ladam''', '''danau melengkung''', '''danau mati''', atau '''danau sudetan''') adalah sebuah danau berbentuk "huruf U" yang terbentuk ketika sebuah [[kelokan]] yang lebar [[Meander cutoff|terpotong]] dari sungai utamanya, dan akhirnya membentuk sebuah badan air tersendiri.
[[Lake Volta]] in western [[Africa]] covers around 8,500 km². [[Lake Mead]] is North America's largest artificial lake, which was formed by the [[Hoover Dam]], constructed from [[1931]] to [[1935]] under President [[Franklin D. Roosevelt]]. [[Lokka]] is Northern Europe's largest artificial lake, 417 km<sup><small>2</sup></small> in size.
=== Danau bendungan alami ===
See also: [[List of reservoirs and dams]]
[[Danau bendungan alami]] yaitu danau yang terbentuk akibat [[lembah]] sungai terbendung oleh aliran [[lava]] saat [[erupsi]] terjadi.
=== Danau buatan ===
==Characteristics==
[[Danau buatan]] yaitu danau yang terbentuk akibat aktivitas manusia.
The change in level of a lake is controlled by the difference between the sources of inflow and outflow, compared to the total volume of the lake. The significant input sources are precipitation onto the lake; runoff carried by streams and channels from the lake's [[catchment]] area; [[groundwater]] channels and aquifers, and man-made sources from outside the catchment area. Output sources are evaporation from the lake; surface and groundwater flows, and any extraction of lake water by humans. As climate conditions and human water requirements vary, these will create fluctuations in the lake level.
== Fungsi ==
Lakes can be categorized on the basis of their richness of nutrients, which typically effects plant growth. Nutrient poor lakes are said to be ''oligotrophic'', and are generally clear, having a low concentration of plant life. ''Mesotropic'' lakes have good clarity and an average level of nutrients. ''Eutrophic'' lakes are enriched with nutrients, resulting in good plant growth and possible [[algae|algal]] blooms. A ''hypertrophic'' lake is a water body that has been highly enriched with nutrients. These lakes typically have poor clarity and are subject to algal blooms. Lakes typically reach this condition due to human activities, such as heavy use of fertilizers in the lake catchment area. Such lakes are of little use, and have a poor ecosystem.
Danau memiliki fungsi utama untuk menstabilkan aliran air. Selain itu, danau juga mempunyai fungsi ekonomi yang sangat tinggi, yaitu untuk penyediaan air bersih, baik untuk minum, [[irigasi]], dan industri, juga untuk perikanan budidaya maupun perikanan tangkap. Jika dikelola dengan benar, maka danau akan berfungsi secara optimal sebagai penyangga kehidupan. Penjagaan kuantitas dan kualitas air danau diharapkan dapat menjamin ketersediaan air baku sepanjang daerah alirannya.<ref>{{citation|title= Pemanfaatan Air Danau Sebagai Sumber Irigasi|authors= Agung Pamudjianto, Wilis Sutiono|year= 2018|accessdate= 26 Desember 2020|page= 2|url= https://osf.io/9zb2u/}}</ref> Fungsi lain dari danau yaitu adalah sumber air, penopang fungsi biodiversitas, sarana [[transportasi]] dan olah raga dan [[wisata]], peredam fluktuasi [[banjir]] di sungai, sumber dan tempat pembentukan protein, pengendali toksisitas di badan air, sumber yang mengisi air tanah, pengendali iklim, serta posisinya yang sentral dalam tradisi, budaya, maupun religi.<ref>{{Cite journal|last=Soeprobowati, T.R.|first=|date=2012|title=Peta Batimetri Danau Rawapening|url=https://core.ac.uk/download/pdf/20530338.pdf|journal=Bioma|volume=14|issue=2|pages=75|doi=}}</ref>
== AbioticDanau and biotic limnologyterkenal ==
[[Berkas:Danau Toba.jpg|240px|jmpl|[[Danau Toba]] di [[Sumatra]], [[Indonesia]].]]
[[Image:Lake.jpg|thumb|right|250px|Lake Billy Chinook, Deschutes National Forest, Oregon]]
* Danau terbesar di dunia adalah [[Laut Kaspia]]. Dengan luas permukaan 394.299 [[kilometer persegi|km²]], ia memiliki wilayah yang lebih besar dari enam danau terbesar di dunia jika digabungkan menjadi satu.
[[Limnology]] divides lakes in three zones: [[littoral zone]], which is a sloped area that is close to land; [[open-water zone]], where sunlight is abundant; and [[deep-water zone]], where little sunlight can reach. The depth which light can reach in lakes depends on the density and motion of [[Particle_%28ecology%29|particle]]s. These particles can be [[sediment]]ary or biological in origin and are responsible for the color of the water. Decaying plant matter for instance is responsible for a yellow or brown color, while algae result in greenish water. In very shallow water bodies, iron oxides make water reddish brown. Biological particles are [[alga]]e and [[detritus]]. A sediment particle is in [[Suspension (chemistry)|suspension]] if its weight is less than the random turbidity [[force]]s acting upon it. The turbidity is a decisive factor in the transparency of the water. Bottom-dwelling detritivorous [[fish]] are responsible for turbid waters, because they stir the mud in search for food. Piscivorous fish eat plant-eating (planktonivorous) fish, thus increasing the number of algae (see [[aquatic trophic cascade]]). The light depth or transparency is measured by using a [[Secchi disk]]. This is a 20 cm disk with alternating white and black quadrants. The depth at which the disk is no longer visible, is the Secchi depth, and is a measure for transparency. It is commonly used to test [[eutrophication]].
* Danau air tawar terbesar, dan kedua terbesar adalah [[Danau Superior]] dengan luas permukaan 82.414 km².
* Danau terdalam adalah [[Danau Baikal]] di [[Siberia]], dengan kedalaman 1.741 [[meter]] (5.712 [[kaki]]).
* Danau tertinggi yang dapat dinavigasi adalah Danau [[Titicaca]], pada ketinggian 3.821 m di atas permukaan laut. Dia juga merupakan danau terbesar kedua di [[Amerika Selatan]].
* Danau terendah di dunia adalah [[Laut Mati]], pada 396 m (1.302 kaki) di bawah permukaan laut. Dia juga merupakan danau yang memiliki konsentrasi [[garam]] paling tinggi.
* Pulau terbesar di tengah danau air tawar adalah [[Pulau Manitoulin]] di [[Danau Huron]], dengan luas permukaan 2.766 km².
* Danau terbesar yang terletak di pulau adalah [[Danau Nettiling]] di [[Pulau Baffin]].
* [[Danau Toba]] di pulau [[Sumatra]] kemungkinan terletak di kawah gunung berapi pasif terbesar di dunia. Danau Toba dinobatkan sebagai danau vulkanik terbesar di dunia.
[[Berkas: Panoramaninjau.jpg|240px|jmpl|Panorama [[Danau Maninjau]] di [[Sumatera Barat]]]]
A lake moderates the surrounding region's [[temperature]] and [[climate]] because [[water]] has a very high [[specific heat capacity]] (4186). In the daytime, the lake can cool the land beside it with [[local winds]], resulting in a [[sea breeze]]; in the night, it can warm it, forming a [[land breeze]].
== HowLihat lakes disappearpula ==
* [[Danau hipersalin]]
A lake may be deposited with sediment, and gradually, the lake becomes a [[wetland]], such as a [[swamp]] or [[marsh]]. An important difference exists between lowland and highland lakes: lowland lakes are more placid, are less rocky/more sedimentary, have a less sloping bottom, and generally contain more plant life. Large water plants (typically [[reed (plant)|reed]]s) accelerate this closing process significantly because they trap sediment. Turbid lakes, and lakes with much plant-eating fish, tend to disappear slower. A "disappearing" lake (barely noticeable on a human timescale) typically has a water's edge with extensive plant mats. They become a new habitat for other plants (like [[Sphagnum|peat moss]], when conditions are right) and animals, many of which are very rare. Gradually, the lake closes, and young [[peat]] may form, forming a [[fen]]. In lowland river valleys (allowing the river to [[meander]]), the presence of peat is explained by the closing of historical [[oxbow lake]]s. In the very last stages of [[succession]], more [[tree]]s would grow in, eventually turning the wetland into a [[forest]].
* [[Daftar danau]]
* [[:Kategori:Danau di Indonesia|Daftar danau di Indonesia]]
* [[Daftar danau terbesar di dunia]]
* [[Daftar danau terdalam di dunia]]
* [[Fakta geografi dunia]]
* [[Pulau danau]]
* [[Kolam]]
* [[Limnologi]]
* [[Laguna]]
* [[Geografi]]
== Referensi ==
Some lakes can also disappear seasonally; they are called [[Intermittent lake]]s and are typical of [[Karst|karstic terrain]]. A prime example of this is [[Lake Cerknica]] in [[Slovenia]].
{{sectstubreflist}}
== Extraterrestrial lakes ==
At present the surface of the planet [[Mars (planet)|Mars]] is too cold to permit pooling of liquid water on the surface. However geologic evidence appears to confirm that ancient lakes once formed on the surface. It is also possible that volcanic activity on Mars will occasionally melt the subsurface ice, forming large lakes. Under current conditions this water will quickly evaporate or freeze unless insulated in some manner, such as by a coating of volcanic ash.
[[Jupiter (planet)|Jupiter]]'s small moon [[Io]] is volcanically active due to tidal stresses, and as a result [[sulfur]] deposits have accumulated on the surface. Some photographs taken during the [[Galileo spacecraft|Galileo mission]] appear to show lakes of liquid sulfur on the surface.
-->
== Lihat pula ==
*[[Daftar danau]]
*[[Daftar danau terbesar di dunia]]
*[[Fakta geografi dunia]]
*[[Kolam]]
*[[Limnologi]]
*[[Laguna]]
*[[Geografi]]
*[[Tarn (danau)|Tarn]]
== Pranala luar ==
* {{en}} [http://www.highestlake.com/ Lists of the highest lakes in the US and the world] {{Webarchive|url=https://web.archive.org/web/20070518021100/http://www.highestlake.com/ |date=2007-05-18 }}
* {{en}} [http://www.mlswa.org/lkclassif1.htm Lake Classification Systems] {{Webarchive|url=https://web.archive.org/web/20080212124510/http://www.mlswa.org/lkclassif1.htm |date=2008-02-12 }}
{{Authority control}}
[[Kategori:Bentang alam]]
[[Kategori:Danau| ]]
[[Kategori:Geografi]]
[[ar:بحيرة]]
[[arc:ܝܡܬܐ]]
[[ast:Llagu]]
[[az:گول]]
[[ba:Күл]]
[[be-x-old:Возера]]
[[bg:Езеро]]
[[br:Lenn (dour)]]
[[ca:Llac]]
[[cr:Sákahikan]]
[[cs:Jezero]]
[[cv:Кӳлĕ]]
[[cy:Llyn]]
[[da:Sø]]
[[de:See (Gewässer)]]
[[el:Λίμνη]]
[[eml:Lèg]]
[[en:Lake]]
[[eo:Lago]]
[[es:Lago]]
[[et:Järv]]
[[eu:Laku]]
[[fa:دریاچه]]
[[fi:Järvi]]
[[fr:Lac]]
[[fur:Lâc]]
[[gl:Lago]]
[[he:אגם]]
[[hi:झील]]
[[hr:Jezero]]
[[hu:Tó]]
[[io:Lago]]
[[it:Lago]]
[[ja:湖]]
[[jbo:lalxu]]
[[ka:ტბა]]
[[ko:호수]]
[[la:Lacus]]
[[lb:Séi]]
[[lt:Ežeras]]
[[lv:Ezers]]
[[mk:Езеро]]
[[ml:തടാകം]]
[[nah:Ātezcatl]]
[[nl:Meer (water)]]
[[nn:Innsjø]]
[[no:Innsjø]]
[[pl:Jezioro]]
[[pt:Lago]]
[[qu:Qucha]]
[[ro:Lac]]
[[ru:Озеро]]
[[sh:Jezero]]
[[simple:Lake]]
[[sk:Jazero]]
[[sl:Jezero]]
[[sr:Језеро]]
[[su:Situ]]
[[sv:Insjö]]
[[sw:Ziwa]]
[[ta:ஏரி]]
[[th:ทะเลสาบ]]
[[tr:Göl]]
[[uk:Озеро]]
[[vec:Łago]]
[[vi:Hồ]]
[[yi:אזערע]]
[[zh:湖泊]]
[[zh-yue:湖]]
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