View source for Place:Danube

{{Short description|Second-longest river in Europe}}
{{Infobox river
| name               = Danube 
| native_name        = {{native name list
|tag1=de  |name1=Donau    |tag2=sk  |name2=Dunaj    |tag3=hu  |name3=Duna     |tag4=sh  |name4={{lang|sh-Latn|Dunav}} {{lang|sh-Cyrl|/ Дунав}}
|tag5=bg  |name5=Дунав    |tag6=ro  |name6=Dunărea  |tag7=uk  |name7=Дунай    }}
<!-- IMAGE & MAP -->
| image              = View from Gellért Hill to the Danube, Hungary - Budapest (28493220635).jpg
| image_caption      = The Danube in [[Place:Budapest|Budapest]]
| map                = Danubemap.png
| map_caption        = Course of the Danube, marked in red
<!-- LOCATION -->
| subdivision_type1  = Countries
| subdivision_name1  = {{hlist|Germany|Austria|Slovakia|Hungary|Croatia|Serbia|Bulgaria|Romania|Moldova|Ukraine}}
| subdivision_type5  = Cities
| subdivision_name5  = {{hlist|Ulm|Ingolstadt|Regensburg|Passau|[[Place:Linz|Linz]]|[[Place:Vienna|Vienna]]|[[Place:Bratislava|Bratislava]]|Győr|[[Place:Budapest|Budapest]]|Dunaújváros||Mohacs|Apatin|Vukovar||Ilok|Bačka Palanka||Novi Sad||Sremski Karlovci|Zemun|[[Place:Belgrade|Belgrade]]|Pančevo|[[Place:Smederevo|Smederevo]]|Drobeta-Turnu Severin|[[Place:Vidin|Vidin]]|Giurgiu|Ruse|Călărași|Brăila|Galați|Izmail|Tulcea|Sulina}}
<!-- PHYSICAL CHARACTERISTICS -->
| length             = {{convert|2,850|km|mi|abbr=on}}<ref>{{cite encyclopedia|url=https://www.britannica.com/place/Danube-River|title=Danube River|encyclopedia=Encyclopædia Britannica |edition=Online |access-date=30 April 2022}}</ref>
| width_min          = Middle Danube (Iron Gates) {{cvt|150|m|abbr=on}}; Lower Danube (Brăila) {{cvt|400|m|abbr=on}}<ref name="Long-term Morphological Development of the Danube in Relation to the Sediment Balance"/>
| width_avg          = Upper Danube {{cvt|300|m|abbr=on}}; Middle Danube {{cvt|400|m|abbr=on}} to {{cvt|800|m|abbr=on}}; Lower Danube {{cvt|900|m|abbr=on}} to {{cvt|1,000|m|abbr=on}}<ref name="Hydromorphological balance of the Danube River Channel on the Sector between Bazias (km 1072.2) and Danube Delta Inlet (km 80.5)">{{cite web|url=https://www.osce.org/files/f/documents/0/8/32944.pdf |title=Hydromorphological balance of the Danube River Channel on the Sector between Bazias (km 1072.2) and Danube Delta Inlet (km 80.5) |last=Bondar |first=Constantin |publisher=osce.org |access-date=30 April 2022}}</ref><ref name="Long-term Morphological Development of the Danube in Relation to the Sediment Balance"/><ref name="ICPDR">{{cite web|url=http://www.icpdr.org|title=ICPDR}}</ref>
| width_max          = Middle Danube {{cvt|1,500|m|abbr=on}}; Lower Danube {{cvt|1,700|m|abbr=on}}<ref name="ICPDR"/><ref name="Long-term Morphological Development of the Danube in Relation to the Sediment Balance">{{cite web|url=https://www.interreg.eu|title=Long-term Morphological Development of the Danube in Relation to the Sediment Balance}}</ref>
| depth_min          = {{cvt|1|m|abbr=on}} (Upper Danube)<ref name="ICPDR">{{cite web|url=http://www.icpdr.org|title=ICPDR}}</ref>
| depth_avg          = Upper Danube {{cvt|8|m|abbr=on}}; Middle Danube {{cvt|6|m|abbr=on}} to {{cvt|10|m|abbr=on}}, {{cvt|53|m|abbr=on}} (Iron Gates); Lower Danube {{cvt|9|m|abbr=on}}<ref name="Hydromorphological balance of the Danube River Channel on the Sector between Bazias (km 1072.2) and Danube Delta Inlet (km 80.5)"/><ref name="Long-term Morphological Development of the Danube in Relation to the Sediment Balance"/><ref name="ICPDR"/><ref name="Republic Hydrometeorological Service of Serbia">{{cite web|url=http://www.hidmet.gov.rs|title=Republic Hydrometeorological Service of Serbia}}</ref>
| depth_max          = Middle Danube (Iron Gates) {{cvt|90|m|abbr=on}}; Lower Danube {{cvt|34|m|abbr=on}}<ref name="Long-term Morphological Development of the Danube in Relation to the Sediment Balance"/>
| discharge1_location= Before the Danube Delta
| discharge1_min     = {{convert|1,790|m3/s|cuft/s|abbr=on}}<ref name="hidrogycal">{{citation|url=https://www.limnology.ro/water2012/Proceedings/001.pdf |title=The Danube River in the Pontic Sector – Hidrologycal Regime |last1=Gâştescu |first1=Petre |last2=Țuchiu |first2=Elena |work=Water resources and wetlands: Conference Proceedings |location=Tulcea, Romania |editor-first1=Petre |editor-last1=Gâştescu |editor-first2=William |editor-last2=Lewis William.Jreditor-first3=Petre |editor-last3=Breţcan |date=2012 |isbn=978-606-605-038-8 |page=18}}</ref> 
| discharge1_avg     = (Period: 1931–2010) {{convert|6,510|m3/s|cuft/s|abbr=on}}<ref name="hidrogycal"/>
(Period: 1970–2015) {{convert|6,546|m3/s|cuft/s|abbr=on}}<ref>{{cite web|url=https://unece.org/DAM/env/documents/2019/ece/Restart/Ukraine_S1/Points_of_view_expressed_by_the_Romanian_authorutues_and_scientific_research_institute.pdf |title=Points of view expressed by the Romanian authorities and scientific research on the Ukraine's document "Annotated Report on Scientific Research – Complex Environmental Monitoring for the Danube – Black Sea Deep Water Navigation Canal operation in 2017–2018. The Sea Approach Canal Zone" |publisher=unece.org |access-date=30 April 2022}}</ref>
(Period: 1840–2006) {{convert|6,471|m3/s|cuft/s|abbr=on}}<ref name="Hydromorphological balance of the Danube River Channel on the Sector between Bazias (km 1072.2) and Danube Delta Inlet (km 80.5)"/>
(Period: 2000–2020) {{cvt|6,464.9|m3/s|cuft/s|abbr=on}}<ref name="ICPDR"/>
| discharge1_max     = {{convert|15,900|m3/s|cuft/s|abbr=on}}<ref name="hidrogycal"/> 
| discharge2_location= Passau, Bavaria, Germany<br />{{cvt|30|km}} before town
| discharge2_avg     = {{convert|580|m3/s|cuft/s|abbr=on}}
| discharge3_location= [[Place:Vienna|Vienna]], Austria
| discharge3_avg     = {{convert|1,900|m3/s|cuft/s|abbr=on}}
| discharge4_location= [[Place:Budapest|Budapest]], Hungary
| discharge4_avg     = {{convert|2,350|m3/s|cuft/s|abbr=on}}
| discharge5_location= [[Place:Belgrade|Belgrade]], Serbia
| discharge5_avg     = {{convert|5,600|m3/s|cuft/s|abbr=on}} 
<!-- BASIN FEATURES -->
| source1            = Breg
| source1_location   = Furtwangen im Schwarzwald, Baden-Württemberg, Germany
| source1_coordinates= {{coord|48|05|44|N|08|09|18|E|display=inline}}
| source1_elevation  = {{convert|1078|m|abbr=on}}
| source2            = Brigach 
| source2_location   = St. Georgen im Schwarzwald, Baden-Württemberg, Germany
| source2_coordinates= {{coord|48|06|24|N|08|16|51|E|display=inline}}
| source2_elevation  = {{convert|940|m|abbr=on}}
| source_confluence_location   = Donaueschingen, Baden-Württemberg, Germany
| source_confluence_coordinates= {{coord|47|57|03|N|08|31|13|E|display=inline}}
| mouth              = Danube Delta
| mouth_location     = Romania
| mouth_coordinates  = {{coord|45|13|3|N|29|45|41|E|display=inline,title}}
| basin_size         = {{convert|801463|km2|abbr=on}}
}}

The '''Danube''' ({{IPAc-en|ˈ|d|æ|n|.|j|uː|b}} {{respell|DAN|yoob}}; {{small|known by various names in other languages}}) is the second-longest river in Europe, after the Volga in {{wipe|Russia}}. It flows through much of [[Place:Central Europe|Central]] and Southeastern Europe, from the Black Forest into the Black Sea. A large and historically important river, it was once a frontier of the Roman Empire and today connects ten European countries, running through their territories or being a border. Originating in {{wipe|Germany}}, the Danube flows southeast for {{convert|2850|km|mi|sp=us|abbr=on}}, passing through or bordering Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldova, and {{wipe|Ukraine}}. Among the many cities on the river are four national capitals: [[Place:Vienna|Vienna]], [[Place:Bratislava|Bratislava]], [[Place:Budapest|Budapest]], and [[Place:Belgrade|Belgrade]]. Its drainage basin amounts to 817 000 km² and extends into nine more countries. 

The Danube's longest headstream Breg rises in Furtwangen im Schwarzwald, while the river carries its name from its source confluence in Donaueschingen onwards. Since ancient times, the Danube has been a traditional trade route in Europe. Today, {{convert|2415|km|mi|abbr=on}} of its total length are navigable. The Danube is linked to the North Sea via the Rhine–Main–Danube Canal, connecting the Danube at Kelheim with the Main at Bamberg. The river is also an important source of [[Physics:Hydropower|hydropower]] and drinking water. 

The Danube river basin is home to fish species such as [[Biology:Northern pike|pike]], zander, [[Biology:Huchen|huchen]], [[Biology:Wels catfish|Wels catfish]], [[Biology:Burbot|burbot]] and [[Biology:Tench|tench]]. It is also home to a large diversity of carp and [[Biology:Sturgeon|sturgeon]], as well as salmon and [[Biology:Trout|trout]]. A few species of [[Biology:Euryhaline|euryhaline]] fish, such as European [[Biology:European bass|seabass]], [[Biology:Mullet (fish)|mullet]], and [[Biology:European eel|eel]], inhabit the Danube Delta and the lower portion of the river.

==Names and etymology==
===Other names===
Today the river carries its name from its source confluence in Donaueschingen onwards. Its longest headstream Breg rises in Furtwangen im Schwarzwald.
The river was known to the {{wipe|Ancient Greece}} as the {{lang|grc-Latn|Istros}} ({{lang|grc|Ἴστρος}})<ref>{{Cite web|url=https://www.perseus.tufts.edu/hopper/text?doc=urn:cts:greekLit:tlg0016.tlg001.perseus-grc1:4.48|title=Herodotus, The Histories, book 4, chapter 48|website=www.perseus.tufts.edu}}</ref> a borrowing from a Daco-Thracian name meaning 'strong, swift', from a root possibly also encountered in the ancient name of the Dniester ({{lang|la|Danaster}} in Latin, {{lang|grc-Latn|Tiras}} in Greek) and akin to Iranic {{lang|ira|turos}} 'swift' and [[Social:Sanskrit|Sanskrit]] {{lang|sa-Latn|iṣiras}} ({{lang|sa|इषिरस्}}) 'swift', from the [[Social:Proto-Indo-European language|PIE]] {{PIE|*''isro-''}}, {{PIE|*''sreu''}} 'to flow'.<ref name="Felecan & Felecan 2015">{{cite journal |title=Straturi etimologice reflectate în hidronimia românească |first1=Oliviu |last1=Felecan |first2=Nicolae |last2=Felecan |page=254 |journal=Quaderns de Filologia: Estudis Lingüístics |volume=20 |year=2015 |issue=1 |publisher=Universitat de València |doi=10.7203/qfilologia.20.7521 |url=http://roderic.uv.es/bitstream/10550/49693/1/5283423.pdf |doi-access=free }}</ref> In the Middle Ages, the Greek {{lang|grc-Latn|Tiras}} was borrowed into Italian as {{lang|it|Tyrlo}} and into Turkic languages as {{lang|trk|Tyrla}}; the latter was further borrowed into Romanian as a regionalism ({{lang|ro|Turlă}}).<ref name="Felecan & Felecan 2015"/>

The Thraco-[[Social:Phrygian language|Phrygian]] name was {{lang|xpg-Latn|Matoas}},<ref>{{cite journal |title=Matoas, the Thraco-Phrygian name for the Danube, and the IE root *madų |first=Robert |last=Dyer |journal=Glotta |volume=52 |year=1974 |issue=1/2 |pages=91–95 |publisher=Vandenhoeck & Ruprecht (GmbH & Co. KG) |jstor=40266286}}</ref> "the bringer of luck".<ref name="Šašel2009">{{cite book |first=Marjeta |last=Šašel Kos |language=sl, en |url=http://iza.zrc-sazu.si/pdf/Sasel_Kos_Ukrocena_lepotica.pdf |pages=42–50 |chapter=Reka kot božanstvo&nbsp;— Sava v antiki |trans-chapter=River as a Deity&nbsp;– The Sava in Antiquity |editor-first=Jožef |editor-last=Barachini |title=Ukročena lepotica: Sava in njene zgodbe |trans-title=The Tamed Beauty: The Sava and Its Stories |isbn=978-961-92735-0-0 |year=2009 |place=Sevnica |publisher=Javni zavod za kulturo, šport, turizem in mladinske dejavnosti |url-status=dead |archive-url=https://web.archive.org/web/20160304041135/http://iza.zrc-sazu.si/pdf/Sasel_Kos_Ukrocena_lepotica.pdf |archive-date=4 March 2016  }}</ref>

The [[Social:Middle Mongol language|Middle Mongolian]] name for the Danube was transliterated as ''Tho-na'' in 1829 by Jean-Pierre Abel-Rémusat.<ref name="Abel-Remusat">{{cite book |last=Abel-Rémusat |first=Jean-Pierre |title=Nouveaus Mélanges Asiatiques |volume=2 |location=Paris |publisher=Schubart and Heidelhoff |year=1829 |pages=96–97}}</ref>

The modern languages spoken in the Danube basin all use names related to {{lang|la|Dānuvius}}:
{{lang-de|link=German language|Donau}} ({{IPA-de|ˈdoːnaʊ|IPA|de-Donau.ogg}});
{{lang-ro|Dunărea}} ({{IPA-ro|ˈdunəre̯a|IPA}}; via German);<ref name="Vékony">{{Cite book |last=Vékony |first=Gábor |year=2000 |title=Dacians, Romans, Romanians |publisher=Matthias Corvinus Publishing |isbn=978-1-882785-13-1 |page=[https://archive.org/details/daciansromansrom0000veko/page/210 210] |url-access=registration |url=https://archive.org/details/daciansromansrom0000veko/page/210 }}</ref>
{{Lang-szl|Dōnaj}};
{{lang-cz|Dunaj}} ({{IPA-cs|ˈdunaj|IPA}});
{{lang-sk|Dunaj}} ({{IPA-sk|ˈdunaj|IPA}});
{{lang-pl|Dunaj}} ({{IPA-pl|ˈdunaj|IPA|pl-Dunaj.ogg}});
{{lang-hu|Duna}} ({{IPA-hu|ˈdunɒ|IPA|hu-Duna.ogg}});
{{lang-sl|Donava}} ({{IPA-sl|ˈdóːnaʋa|IPA}});
{{lang-sh-Latn-Cyrl|separator=" / "|Dunav|Дунав}} ({{IPA-sh|dǔna(ː)ʋ|IPA}});
{{lang-bg|Дунав|Dunav}} ({{IPA-bg|ˈdunɐf|IPA}});
{{lang-ru|Дунай|Dunaj}} ({{IPA-ru|dʊˈnaj|IPA}});
{{lang-uk|Дунай|Dunaj}} ({{IPA-uk|dʊˈnɑj|IPA}});
{{lang-gr|Δούναβης}} ({{IPA-el|ˈðunavis|IPA}});
{{lang-it|Danubio}} ({{IPA-it|daˈnuːbjo|IPA}});
{{lang-es|Danubio}}; ({{IPA-es|daˈnuβjo|IPA}});
{{Lang-tr|Tuna}};
{{lang-rm|Danubi}};
{{lang-sq|Tunë}}, {{Lang-sq-definite|Tuna}}.<ref>{{citation |page=624 |publisher=Akademia e Shkencave e RPS te Shqiperise, Instituti i Kultures Popullore, Sektori i Prozes dhe Poezise |editor1=Kozma Vasili |editor2=Arsen Mustaqi |title=Lirika popullore |trans-title=Folk lyrics |series=Folklor Shqiptar |volume=4 |language=sq |issue=3 – Kenge per nizamet dhe kurbetin |year=1981 |location=Tirana |quote=Tunë-a lumi i Danubit }}</ref>

===Etymology===
''Danube'' is an [[Social:Old European hydronymy|Old European]] river name derived from the Celtic 'danu' or 'don'<ref name="Bromwich">Triad 35. Bromwich, ''Trioedd Ynys Prydein'', pp. 280–285.</ref> (both Celtic gods), which itself derived from the [[Social:Proto-Indo-European language|Proto-Indo-European]] {{PIE|*''dānu''}}. Other European river names from the same root include the Dunaj, Dzvina/Daugava, Don, Donets, Dnieper, Dniestr, Dysna and Tana/Deatnu. In Rigvedic Sanskrit, ''dānu'' (दनु) means "fluid, dewdrop" and ''dānuja (दनु-ज)'' means "born from ''dānu''" or "born from dew-drops". In Avestan, the same word means "river".  The [[Social:Finnish language|Finnish]] word for Danube is {{wikt-lang|fi|Tonava}}, which is most likely derived from the name of the river in [[Social:German language|German]], {{lang|de|Donau}}. Its [[Social:Sami languages|Sámi]] name {{lang|smi|Deatnu}} means "Great River". It is possible that {{lang|xsc|dānu}} in Scythian as in Avestan was a generic word for "river": ''Dnieper'' and ''Dniestr'', from ''Danapris'' and ''Danastius'', are presumed to continue Scythian {{lang|xsc|*dānu apara}} "far river" and {{lang|xsc|*dānu nazdya-}} "near river", respectively.<ref name="Mallory, J.P 2000. p. 106">{{cite book |last1=Mallory |first1=J.P |author-link2=Victor H. Mair |first2=Victor H. |last2=Mair |title=The Tarim Mummies: Ancient China and the Mystery of the Earliest Peoples from the West |url=https://archive.org/details/tarimmummiesanci00mall |url-access=registration |location=London |publisher=Thames and Hudson |year=2000 |page=[https://archive.org/details/tarimmummiesanci00mall/page/106 106] |isbn=9780500051016 }}. {{cite book |url=http://i.ironau.ru/pdf/osjazfolk1949.pdf |author=V. I. Adaev |script-title=ru:Осетинский язык и фольклор |trans-title=Ossetian language and folklore |location=Moscow |publisher=Publishing house of Soviet Academy of Sciences |year=1949 |page=236 |language=ru }}</ref>

In Latin, the Danube was variously known as {{lang|la|Danubius}}, {{lang|la|Danuvius}}, {{lang|la|Ister}}<ref>{{cite book|title=Ancient Languages of the Balkans, Part One|location=Paris|publisher=Mouton|year=1976|page=144}}</ref> or ''Hister''. The Latin name is masculine, as are all its [[Social:Slavic languages|Slavic]] names, except Slovene (the name of the [[Place:Rhine|Rhine]] is also masculine in Latin, most of the Slavic languages, as well as in German). The German {{lang|de|Donau}} (Early Modern German {{lang|de|Donaw}}, {{lang|de|Tonaw}},<ref>{{lang|de|Tonaw}} in {{cite book|author=Sebastian Franck |title=Weltbuch |year=1542 |url=https://books.google.com/books?id=dk9QLBxWmxcC&q=tonach&pg=PT167 |page=81 |author-link=Sebastian Franck}} {{lang|de|Donaw}} e.g. in {{cite book |author=Leonhard Thurneisser zum Thurn |title=Pison |year=1572 |url=https://books.google.com/books?id=PWhWAAAAcAAJ&pg=PR186|page=186}} Spelling {{lang|de|Donau}} from the 17th century.</ref> [[Social:Middle High German|Middle High German]] {{lang|gmh|Tuonowe}})<ref>{{cite book|author=Grimm|title=Deutsche Grammatik|page=[https://archive.org/details/bub_gb_VXTJ_C205t4C/page/n426 407]|title-link=Deutsche Grammatik}}</ref> is feminine, as it has been re-interpreted as containing the suffix ''-ouwe'' "wetland".

[[Social:Romanian language|Romanian]] differs from other surrounding languages in designating the river with a feminine term, {{lang|ro|Dunărea}} ({{IPA-ro|ˈdunəre̯a|IPA}}).<ref name="Felecan & Felecan 2015"/> This form was not inherited from Latin, although Romanian is a Romance language.<ref name="Vékony" /> To explain the loss of the Latin name, scholars who suppose that Romanian developed near the large river propose<ref name="Vékony"/> that the Romanian name descends from a hypothetical [[Social:Thracian language|Thracian]] {{lang|txh|*Donaris}}. The Proto-Indo-European root of this presumed name is related to the Iranic word "{{lang|ira|don-}}"/"{{lang|ira|dan-}}", while the supposed suffix {{lang|ira|-aris}} is encountered in the ancient name of the Ialomița River, ''Naparis'', and in the unidentified ''Miliare'' river mentioned by Jordanes in his Getica.<ref name="Felecan & Felecan 2015"/> Gábor Vékony says that this hypothesis is not plausible, because the Greeks borrowed the ''Istros'' form from the native Thracians.<ref name="Vékony"/> He proposes that the Romanian name is a loanword from a Turkic language ([[Social:Cuman language|Cuman]] or [[Social:Pecheneg language|Pecheneg]]).<ref name="Vékony"/>

==Geography==
[[File:Danube basin.png|thumb|The Danube [[Earth:Drainage basin|basin]]]]
[[File:Bregquelle 01.jpg|thumb|The hydrogeographical source of the Danube at St. Martin's Chapel in Furtwangen im Schwarzwald: the ''Bregquelle'', the source of the Danube's longest headstream, the Breg, where the Danube is symbolized by the Roman allegory for the river, ''Danuvius''.]]
[[File:Donauquelle Donaueschingen im Sommer.jpg|thumb|The symbolical source of the Danube in Donaueschingen: the source of the Donaubach (''Danube Brook''), which flows into the Brigach.]]

Classified as an international waterway, it originates in the town of Donaueschingen, in the Black Forest of {{wipe|Germany}}, at the [[Earth:Confluence|confluence]] of the rivers Brigach and Breg. The Danube then flows southeast for about {{cvt|2730|km}}, passing through four capital cities ([[Place:Vienna|Vienna]], [[Place:Bratislava|Bratislava]], [[Place:Budapest|Budapest]], and [[Place:Belgrade|Belgrade]]) before emptying into the Black Sea via the Danube Delta in Romania and {{wipe|Ukraine}}.

Once a long-standing frontier of the Roman Empire, the river passes through or touches the borders of 10 countries: Romania (29.0% of basin area), Hungary (11.6%), Serbia (10.2%), Austria (10.0%), {{wipe|Germany}} (7.0%), Bulgaria (5.9%), Slovakia (5.9%), Croatia (4.4%), {{wipe|Ukraine}} (3.8%), and Moldova (1.6%).<ref name=icpdr>{{cite web|url=http://www.icpdr.org/icpdr-pages/countries.htm|title=Countries of the Danube River Basin|publisher=International Commission for the protection of the Danube River|access-date=13 November 2010}}</ref> Its [[Earth:Drainage basin|drainage basin]] extends into nine more (ten if Kosovo is included).

===Drainage basin===
In addition to the bordering countries (see above), the [[Earth:Drainage basin|drainage basin]] includes parts of nine more countries: Bosnia and Herzegovina (4.6% of the basin area), the [[Place:Czech Republic|Czech Republic]] (2.9%), Slovenia (2.0%), Montenegro (0.9%), {{wipe|Switzerland}} (0.2%), Italy (<0.15%), {{wipe|Poland}} (<0.1%), North Macedonia (<0.1%) and Albania (<0.1%).<ref name=icpdr /> The total drainage basin is {{convert|801463|km2|abbr=on}} in area,{{GeoQuelle|DE-BY|GV}}{{GeoSource|Danube||12}} and is home to 83 million people.<ref name="ICPDR-Basin"/> The highest point of the drainage basin is the summit of ''Piz Bernina'' at the Italy–Switzerland border, at {{convert|4049|m|sp=us|abbr=on}}.<ref>{{cite book|url=http://www.unece.org/fileadmin//DAM/env/water/publications/pub76.htm|title=Our Waters: Joining Hands Across Borders. First Assessment of Transboundary Rivers, Lakes and Groundwaters|year=2007|chapter=Drainage basin of the Black Sea |chapter-url=http://www.unece.org/fileadmin/DAM/env/water/blanks/assessment/black.pdf|publisher=United Nations Economic Commission for Europe}}</ref> The Danube River Basin is divided into three main parts, separated by "gates" where the river is forced to cut through mountainous sections:<ref name="ICPDR-Basin">{{Cite web|url=https://www.icpdr.org/main/danube-basin/river-basin|title=River Basin &#124; ICPDR – International Commission for the Protection of the Danube River|website=www.icpdr.org}}</ref>
* '''Upper Basin''', from the headwaters to the Devín Gate. 
* '''Middle Basin''', usually called the Pannonian basin or Carpathian Basin, between the Devín Gate and the Iron Gates. It includes the Hungarian plains Kisalföld and Alföld.
* '''Lower Basin''', from the Iron Gates to the [[Physics:River mouth|river mouth]], including the Danube Delta.

===Discharge===

Mean annual discharge on the hydrological stations (period from 2000 to 2020); 1 - Reni, Isaccea; 2 - Silistra; 3 - Pristol; 4 - Batina, Bezdan; 5 - Nagymaros, Szob; 6 - [[Place:Bratislava|Bratislava]], Wolfsthal; 7 - Untergriesbach<ref name="ICPDR"/><ref name="Republički hidrometeorološki zavod">{{cite web|url=https://www.hidmet.gov.rs|title=Republički hidrometeorološki zavod}}</ref>
{| class="wikitable sortable"
! rowspan="2" |Year 
! colspan="7" |Mean annual discharge (m<sup>3</sup>/s)
|-
!1
!2
!3 
!4
!5
!6
!7
|-
|2000
|6,580.6
|6,198.1
|5,585.9
|2,669.4
|2,627.2
|2,337.9
|1,667.2
|-
|2001
|6,304.3
|5,919.4
|5,421.8
|2,432.5
|2,382.3
|2,231.3
|1,627.6
|-
|2002
|6,837.1
|6,100.1
|5,392
|2,824.9
|2,855.6
|2,683
|1,803.9
|-
|2003
|5,021
|4,571
|3,825
|1,786
|1,722
|1,647
|1,153
|-
|2004
|6,524
|6,088
|5,233
|2,025
|2,013
|1,852
|1,213
|-
|2005
|8,711
|7,659
|6,396
|2,420
|2,329
|2,115
|1,359
|-
|2006
|8,428
|7,370
|6,616
|2,110
|2,503
|2,186
|1,396
|-
|2007
|5,626
|5,195
|4,512
|2,182
|2,136
|1,916
|1,287
|-
|2008
|5,909
|5,358
|4,736
|2,163
|2,079
|1,876
|1,339
|-
|2009
|6,492
|5,990
|5,412
|2,607
|2,441
|2,186
|1,433
|-
|2010
|9,598
|8,515
|7,424
|2,879
|2,615
|2,130
|1,420
|-
|2011
|5,303
|
|
|2,000
|
|
|
|-
|2012
|5,053
|
|
|2,240
|
|
|
|-
|2013
|7,164
|6,558
|5,946
|2,863
|2,684
|2,417
|1,671
|-
|2014
|7,446
|6 901
|5,756
|2,198
|2,036
|1,788
|1,237
|-
|2015
|6,138
|5,722
|4,971
|2,030
|1,903
|1,629
|1,240
|-
|2016
|6,465
|5,993
|5,339
|2,261
|2,196
|1,944
|1,412
|-
|2017
|5,202
|4,813
|4,270
|2,143
|2,041
|1,844
|1,307
|-
|2018
|6,487.8
|5,875.5
|4,891
|1,906.3
|1,808.1
|1,644.1
|1,227.8
|-
|2019
|5,579
|5,168
|4,593
|2,253
|2,114
|1,962
|1,446
|-
|2020
|4,893.5
|
|
|2,180
|
|
|
|}

Multiannual average, minimum and maximum discharge (water period from 1876 to 2010)<ref name="Flood Regime of Rivers in the Danube River Basin">{{cite book|url=https://doi.org/10.31577/2019.9788089139460|title=Flood Regime of Rivers in the Danube River Basin|year=2019 |doi=10.31577/2019.9788089139460 |last1=Pekárová |first1=Pavla |last2=Miklánek |first2=Pavol |isbn=9788089139460 |s2cid=131234947 }}</ref>
{| class="wikitable sortable"
! rowspan="2" |Station 
! colspan="3" |Discharge (m<sup>3</sup>/s)
|-
!Min
!Mean
!Max
|-
|Ceatal Izmail
|1,889
|6,489
|14,673
|-
|Reni, Isaccea
|1,805
|6,564
|14,820
|-
|Zimnicea, Svishtov
|1,411
|6,018
|14,510
|-
|Orșova
|1,672
|5,572
|13,324
|-
|Veliko Gradište
|1,461
|5,550
|14,152
|-
|Pančevo
|1,454
|5,310
|13,080
|-
|Bogojevo
|959
|2,889
|8,153
|-
|Bezdan, Batina
|749
|2,353
|7,043
|-
|Mohács
|667
|2,336
|7,227
|-
|Nagymaros, Szob
|628
|2,333
|7,057
|-
|[[Place:Bratislava|Bratislava]]
|633
|2,059
|7,324
|-
|[[Place:Vienna|Vienna]]
|506
|1,917
|6,062
|-
|Krems an der Donau
|596
|1,845
|5,986
|-
|[[Place:Linz|Linz]]
|468
|1,451
|4,783
|-
|Hofkirchen
|211
|638
|1,943
|-
|Regensburg
|128
|444
|1,330
|-
|Ingolstadt
|83
|312
|965
|-
|Ulm
|6
|38
|153
|}

Simulated water and suspended sediment results from climate-driven decadal study (with STD through specific decade)<ref>{{cite journal|url=https://doi.org/10.1177/0959683611409778|title=Simulating fluvial fluxes in the Danube watershed: The "Little Ice Age" versus modern day|date=2021|doi=10.1177/0959683611409778 |last1=McCarney-Castle |first1=K. |last2=Voulgaris |first2=G. |last3=Kettner |first3=A.J. |last4=Giosan |first4=L. |journal=The Holocene |volume=22 |pages=91–105 |s2cid=129864432 }}</ref>
{| class="wikitable" style="text-align:center;"
 !Water period
 !Average preciptation
in the basin (mm)
 !Average temperature
in the basin (°C)
 !Average discharge
(m<sup>3</sup>/s)
 !Sediment load
(10<sup>6</sup> tons)
 |-
 |1530–1540
 |794
 |9.0
 |6,207
 |72.9
 |-
 |1650–1660
 |885
 |8.4
 |7,929
 |67,3
 |-
 |1709–1719
 |861
 |8.3
 |7,616
 |52.91
 |-
 |1770–1780
 |865
 |8.9
 |7,728
 |74.1
 |-
 |1940–1950
 |778
 |8.9
 |7,209
 |55.0
 |-
 |1960–1970
 |850
 |8.8
 |7,399
 |73.0
 |-
 |1975–1985
 |818
 |9.0
 |7,186
 |77.8
 |-
 |1990–2000
 |790
 |9.5
 |6,570
 |73.8
|}

==Discharge chronology==

Historical average flow to the present day; Measured and reconstructed average water flows from 1742.
The reconstructed and observed streamflow (Q – m<sup>3</sup>/s) at Ceatal Izmail for the 1742 to 2022:<ref name="The first tree-ring reconstruction of streamflow variability over the last ~250 years in the Lower Danube">{{cite web|url=https://doi.org/10.1016/j.jhydrol.2023.129150|title=The first tree-ring reconstruction of streamflow variability over the last ~250 years in the Lower Danube|last1=Nagaviciuc|first1=Viorica|last2=Roibu|first2=Cătălin-Constantin|last3=Mursa|first3=Andrei|last4=Ştirbu|first4=Marian-Ionuţ|last5=Popa|first5=Ionel|last6=Ionita|first6=Monica|year=2023}}</ref><ref name="INHGA">{{cite web|url=https://www.hidro.ro|title=INHGA}}</ref><ref name="Annual Reports">{{cite web|url=https://www.icpdr.org/main/publications/annual-reports|title=Annual Reports}}</ref><ref name="IPCC">{{cite web|url=https://www.ipcc.ch|title=IPCC}}</ref>
{| class="wikitable" style="text-align:center;"
 !Year
 
!m<sup>3</sup>/s
!Year
 !m<sup>3</sup>/s
!Year
 !m<sup>3</sup>/s
!Year
 !m<sup>3</sup>/s
!Year
 !m<sup>3</sup>/s
!Year
!m<sup>3</sup>/s
|-
| colspan="12" |''Reconstructed''
|-
|1742
|5,780
|1751
|6,760
|1761
|6,470
|1771
|9,700
|1781
|5,830
|1791
|5,540
|-
|1743
|5,355
|1752
|7,090
|1762
|6,510
|1772
|6,050
|1782
|6,470
|1792
|6,930
|-
|1744
|5,370
|1753
|4,980
|1763
|5,950
|1773
|4,600
|1783
|7,930
|1793
|7,800
|-
|1745
|4,940
|1754
|6,330
|1764
|6,280
|1774
|6,150
|1784
|8,400
|1794
|5,230
|-
|1746
|7,140
|1755
|6,840
|1765
|6,130
|1775
|6,060
|1785
|7,610
|1795
|6,530
|-
|1747
|5,850
|1756
|6,370
|1766
|8,530
|1776
|6,320
|1786
|6,570
|1796
|6,460
|-
|1748
|6,840
|1757
|6,830
|1767
|6,850
|1777
|5,530
|1787
|6,980
|1797
|6,700
|-
|1749
|6,690
|1758
|8,410
|1768
|8,400
|1778
|7,470
|1788
|5,860
|1798
|6,560
|-
|1750
|5,180
|1759
|5,520
|1769
|5,720
|1779
|6,600
|1789
|7,190
|1799
|9,590
|-
| colspan="2" |
|1760
|6,840
|1770
|10,700
|1780
|6,990
|1790
|6,940
|1800
|6,150
|-
| colspan="2" |'''5,905'''
| colspan="2" |'''6,597'''
| colspan="2" |'''7,154'''
| colspan="2" |'''6,547'''
| colspan="2" |'''6,978'''
| colspan="2" |'''6,749'''
|-
|1801
|7,310
|1811
|8,220
|1821
|6,390
|1831
|6,670
|1841
|6,210
|1851
|7,350
|-
|1802
|6,590
|1812
|5,230
|1822
|5,700
|1832
|4,820
|1842
|5,340
|1852
|6,550
|-
|1803
|6,870
|1813
|6,680
|1823
|6,520
|1833
|5,350
|1843
|6,710
|1853
|7,800
|-
|1804
|6,220
|1814
|7,290
|1824
|6,420
|1834
|6,470
|1844
|6,960
|1854
|5,060
|-
|1805
|7,010
|1815
|6,640
|1825
|8,040
|1835
|7,040
|1845
|7,440
|1855
|7,020
|-
|1806
|6,830
|1816
|8,090
|1826
|5,800
|1836
|9,740
|1846
|6,750
|1856
|5,390
|-
|1807
|7,000
|1817
|8,650
|1827
|6,650
|1837
|6,770
|1847
|7,070
|1857
|4,880
|-
|1808
|5,600
|1818
|6,920
|1828
|8,140
|1838
|10,440
|1848
|5,620
|1858
|5,580
|-
|1809
|7,150
|1819
|6,470
|1829
|8,280
|1839
|9,960
|1849
|5,360
|1859
|5,630
|-
|1810
|8,430
|1820
|6,560
|1830
|7,790
|1840
|5,560
|1850
|7,360
|1860
|7,220
|-
| colspan="2" |'''6,901'''
| colspan="2" |'''7,075'''
| colspan="2" |'''6,973'''
| colspan="2" |'''7,282'''
| colspan="2" |'''6,482'''
| colspan="2" |'''6,248'''
|-
|1861
|5,980
|1871
|8,860
|1881
|8,320
|1891
|5,440
|1901
|5,570
|1911
|5,120
|-
|1862
|5,040
|1872
|5,970
|1882
|5,130
|1892
|5,620
|1902
|5,650
|1912
|6,940
|-
|1863
|3,340
|1873
|5,150
|1883
|7,590
|1893
|5,710
|1903
|5,490
|1913
|6,410
|-
|1864
|6,150
|1874
|4,680
|1884
|5,250
|1894
|4,770
|1904
|4,940
|1914
|6,560
|-
|1865
|5,690
|1875
|5,360
|1885
|5,430
|1895
|6,240
|1905
|6,100
|1915
|9,540
|-
|1866
|3,780
|1876
|7,520
|1886
|5,660
|1896
|6,470
|1906
|6,190
|1916
|7,550
|-
|1867
|6,350
|1877
|6,660
|1887
|5,340
|1897
|7,700
|1907
|6,770
|1917
|6,410
|-
|1868
|5,660
|1878
|7,040
|1888
|6,800
|1898
|4,550
|1908
|4,400
|1918
|4,300
|-
|1869
|5,370
|1879
|8,300
|1889
|6,530
|1899
|4,500
|1909
|5,590
|1919
|7,410
|-
|1870
|7,470
|1880
|5,660
|1890
|4,650
|1900
|6,900
|1910
|7,450
|1920
|6,720
|-
| colspan="2" |'''5,483'''
| colspan="2" |'''6,520'''
| colspan="2" |'''6,070'''
| colspan="2" |'''5,790'''
| colspan="2" |'''5,815'''
| colspan="2" |'''6,770'''
|-
| colspan="12" |''Observed''
|-
|1921
|3,906
|1931
|6,706
|1941
|9,916
|1951
|6,368
|1961
|5,860
|1971
|5,272
|-
|1922
|6,530
|1932
|6,181
|1942
|7,266
|1952
|5,850
|1962
|6,628
|1972
|6,160
|-
|1923
|6,430
|1933
|6,344
|1943
|4,308
|1953
|6,117
|1963
|6,047
|1973
|5,766
|-
|1924
|6,700
|1934
|5,644
|1944
|7,190
|1954
|6,168
|1964
|5,259
|1974
|7,258
|-
|1925
|5,255
|1935
|5,718
|1945
|5,870
|1955
|8,834
|1965
|8,400
|1975
|7,190
|-
|1926
|8,144
|1936
|6,392
|1946
|4,684
|1956
|7,100
|1966
|7,954
|1976
|6,567
|-
|1927
|5,990
|1937
|8,325
|1947
|5,418
|1957
|6,254
|1967
|7,500
|1977
|7,073
|-
|1928
|5,005
|1938
|6,867
|1948
|6,357
|1958
|6,340
|1968
|5,660
|1978
|7,120
|-
|1929
|5,330
|1939
|6,310
|1949
|4,301
|1959
|5,375
|1969
|7,710
|1979
|7,747
|-
|1930
|5,197
|1940
|9,533
|1950
|5,130
|1960
|6,514
|1970
|9,602
|1980
|8,767
|-
| colspan="2" |'''5,888'''
| colspan="2" |'''6,802'''
| colspan="2" |'''6,044'''
| colspan="2" |'''6,492'''
| colspan="2" |'''7,062'''
| colspan="2" |'''6,892'''
|-
|1981
|8,172
|1991
|6,274
|2001
|6,304.3
|2011
|5,303
|2021
|6,018
| colspan="2" rowspan="11" |
|-
|1982
|6,700
|1992
|5,710.8
|2002
|6,837.1
|2012
|5,053
|2022
|5,753
|-
|1983
|5,543
|1993
|4,873
|2003
|5,021
|2013
|7,164
|2023
|–
|-
|1984
|6,325
|1994
|6,031.8
|2004
|6,524
|2014
|7,446
| colspan="2" rowspan="7" |
|-
|1985
|6,449
|1995
|6,223.7
|2005
|8,711
|2015
|6,138
|-
|1986
|6,257
|1996
|7,035.8
|2006
|8,428
|2016
|6,465
|-
|1987
|6,619
|1997
|6,684.2
|2007
|5,626
|2017
|5,202
|-
|1988
|6,383
|1998
|6,804.6
|2008
|5,909
|2018
|6,487.8
|-
|1989
|5,448
|1999
|7,951.5
|2009
|6,492
|2019
|5,579
|-
|1990
|4,194
|2000
|6,580.6
|2010
|9,598
|2020
|4,893.5
|-
| colspan="2" |'''6,209'''
| colspan="2" |'''6,417'''
| colspan="2" |'''6,945'''
| colspan="2" |'''5,973'''
| colspan="2" |'''5,885.5'''
|-
| colspan="12" |''Multiannual average discharge 1742 to 2022:'' ~ '''''6,500''' m<sup>3</sup>/s''
|}

===Tributaries===

[[File:Szeged-tisza3.jpg|thumb|The Tisza is the longest tributary of the Danube.]]


The land drained by the Danube extends into many other countries. Many Danubian tributaries are important rivers in their own right, navigable by barges and other shallow-draught boats. From its source to its outlet into the Black Sea, its main tributaries are (as they enter):

{| style="width:590px;"
|-
| style="width:45%;"|
# Iller (entering at Ulm)
# Lech
# Altmühl (entering at Kelheim)
# Naab (entering at Regensburg)
# Regen (entering at Regensburg)
# Isar
# Inn (entering at Passau)
# Ilz (entering at Passau)
# Enns
# Morava (entering near Devín Castle)
# Rába (entering at Győr)
# Váh (entering at Komárno)
# Hron (entering at Štúrovo)
# Ipeľ
# Sió
# Drava
# Vuka (entering at Vukovar)
#
| style="width:45%;"|
18. Tisza<br/>
19. Sava (entering at [[Place:Belgrade|Belgrade]])<br/>
20. Timiș (river) (entering at Pančevo)<br/>
21. Great Morava<br/>
22. Mlava<br/>
23. Caraș<br/>
24. Jiu (entering at Bechet)<br/>
25. Iskar (entering near Gigen)<br/>
26. Olt (entering at Turnu Măgurele)<br/>
27. Osam (entering near [[Place:Nikopol, Bulgaria|Nikopol, Bulgaria]])<br/>
28. Yantra (entering near Svishtov)<br/>
29. Argeș (entering at Oltenița)<br/>
30. Ialomița<br/>
31. Siret (entering near Galați)<br/>
32. Prut (entering near Galați)
|}

<gallery>
File:Donaueschingen Donauzusammenfluss 20080714.jpg|The Danube's source confluence in Donaueschingen: the ''Donauzusammenfluss'', the confluence of Breg and Brigach.
File:Дунайський біосферний заповідник 2.JPG|0 km, Danube Delta, {{wipe|Ukraine}}
File:Danube Delta ESA23450088.jpeg|Where the Danube Meets the Black Sea ([[Organization:European Space Agency|European Space Agency]] [[Engineering:Sentinel-2|Sentinel-2]] image).
File:The Danube Spills into the Black Sea.jpg|The Danube discharges into the Black Sea (the upper body of water in the image).
</gallery>

===Cities and towns===
[[File:Aerial image of Passau.jpg|thumb|3-color confluence of (from left to right) Inn, Danube, and Ilz in Passau]]
The Danube flows through many cities, including four national capitals (shown below in bold), more than any other river in the world. Ordered from the source to the mouth they are:
*Germany
**Donaueschingen in the State of Baden-Württemberg&nbsp;– rivers Brigach and Breg join to form the Danube
**Möhringen an der Donau in Baden-Württemberg
**Tuttlingen in Baden-Württemberg
**Sigmaringen in Baden-Württemberg
**Riedlingen in Baden-Württemberg
**Munderkingen in Baden-Württemberg
**Ehingen in Baden-Württemberg
**Ulm in Baden-Württemberg
**Neu-Ulm in Bavaria
**Günzburg in Bavaria
**Dillingen an der Donau in Bavaria
**Donauwörth in Bavaria
**Neuburg an der Donau in Bavaria
**Ingolstadt in Bavaria
**Kelheim in Bavaria
**Regensburg in Bavaria
**Straubing in Bavaria
**Deggendorf in Bavaria
**Passau in Bavaria
[[File:Linz Ars electronica center lila DL.jpg|thumb|Danube in Linz, Austria]]
*Austria
**[[Place:Linz|Linz]], capital of Upper Austria
**Krems in Lower Austria
**Tulln in Lower Austria
**'''[[Place:Vienna|Vienna]]'''&nbsp;– capital of Austria and the most populous city on the Danube, where the Danube floodplain is called the ''Lobau'', though the ''Innere Stadt'' is situated away from the main flow of the Danube (it is bounded by the Donaukanal&nbsp;– 'Danube canal').
[[File:Bratislava Panorama R01.jpg|thumb|The Danube in Bratislava, Slovakia]]
*Slovakia
**'''[[Place:Bratislava|Bratislava]]'''&nbsp;– capital of Slovakia
**Komárno
**Štúrovo
[[File:Várhegy2.JPG|thumb|Basilica of Esztergom, Hungary]]
*Hungary
**Mosonmagyaróvár
**Győr
**Komárom
**Esztergom
**Visegrád&nbsp;– This section of the river is also called Danube Bend.
**Vác
**Szentendre
**Göd
**Dunakeszi
**'''[[Place:Budapest|Budapest]]'''&nbsp;– capital of Hungary, the largest city and the largest agglomeration on Danube (about 3,300,000 people).
**Szigetszentmiklós
**Százhalombatta
**Ráckeve
**Adony
**Dunaújváros
**Dunaföldvár
**Paks
**Kalocsa
**Baja
**Mohács
*Croatia
**Vukovar
**Ilok
[[File:Kalemegdanska_terasa_Apr_2011.jpg|thumb|Confluence of river Sava into the Danube beneath Belgrade citadel]]
*Serbia
**Apatin
**Bačka Palanka
**Čerević
**Futog
**Veternik
**Novi Sad&nbsp;– regional capital of Vojvodina
**Sremski Karlovci
**Zemun
**'''[[Place:Belgrade|Belgrade]]'''&nbsp;– capital of Serbia
**Pančevo
**[[Place:Smederevo|Smederevo]]
**Kovin
**Veliko Gradište
**Golubac
**Donji Milanovac
**Kladovo
[[File:Nikopol-danube.jpg|thumb|Danube at Nikopol, Bulgaria in winter]] 
*Bulgaria
**[[Place:Vidin|Vidin]]
**Lom
**Kozloduy
**Oryahovo
**[[Place:Nikopol, Bulgaria|Nikopol]]
**Belene
**Svishtov
**Ruse
**Tutrakan
**Silistra
[[File:Cazaresulinaoras2.jpg|thumb|The Danube in Sulina, Romania]]
*Romania
**Moldova Nouă
**Orșova
**Drobeta-Turnu Severin
**Calafat
**Bechet
**Dăbuleni
**Corabia
**Turnu Măgurele
**Zimnicea
**Giurgiu
**Oltenița
**Călărași
**Fetești
**Cernavodă
**Hârșova
**Brăila&nbsp;– limit of the maritime sector of the Danube
**Galați&nbsp;– largest port on the Danube
**Isaccea
**Tulcea
**Sulina&nbsp;– last city through which it flows
*Moldova
**Giurgiulești
*Ukraine
**Reni
**Izmail
**Kiliia
**Vylkove

{{wide image|Panorama of Danube in Vienna.jpg|1000px|Panorama of the Danube in Vienna}}
{{wide image|DonauknieVisegrad_2.jpg|1000px|The Danube Bend is a curve of the Danube in Hungary, near the city of Visegrád. The [[Earth:Transdanubian Mountains|Transdanubian Mountains]] lie on the right bank (left side of the picture), while the North Hungarian Mountains on the left bank (right side of the picture).}}
{{wide image|Budapest view with Parliament.jpg|1000px|Panorama of the Danube in Budapest with the Hungarian Parliament (left)}}
{{wide image|Budapest from Gellert Hill MC.jpg|1000px|Budapest at night}}
{{wide image|The confluence of the Sava into the Danube at Belgrade.jpg|900px|The confluence of the Sava into the Danube at [[Place:Belgrade|Belgrade]]. Pictured from Belgrade Fortress, Serbia}}
{{Wide image|Belgrade Panorama.jpg|1000px|Panoramic image of the Danube and Sava river from Kalemegdan, Belgrade Serbia.}}
{{wide image|Pano-Donau-Danube.jpg|1000px|The Danube entering the Iron Gate at the South-Western end of the [[Place:Carpathian Mountains|Carpathian Mountains]]. Romania on the left side, Golubac Fortress and Serbia on the right side.}}

===Islands===
[[File:Budapest by air.jpg|thumb|Aerial view of Margaret Island, Budapest, Hungary. There are 15 bridges over the Danube in Budapest.]]
[[File:Belgrade_Aerial_K1.jpg|thumb|Great War Island in Belgrade, Serbia. It is located at the confluence of the Sava and Danube.]]
[[File:Ada Kaleh.jpg|thumb|The Ada Kaleh island in the Danube was forgotten during the peace talks at the Congress of Berlin in 1878, which allowed it to remain a ''de jure'' Turkish territory and the Ottoman Sultan Abdul Hamid II's private possession until the Treaty of Lausanne in 1923 (''de facto'' until Romania unilaterally declared its sovereignty on the island in 1919 and further strengthened it with the Treaty of Trianon in 1920).<ref name="LausanneTreaty">{{Citation|date=24 July 1923|title=Treaty of Peace with Turkey signed at Lausanne|place=Lausanne, Switzerland|access-date=6 December 2014|url=http://wwi.lib.byu.edu/index.php/Treaty_of_Lausanne}}</ref><ref name="Ada Kaleh">{{cite web|url=http://alexisphoenix.org/adakaleh.php|title=Ada Kaleh|website=alexisphoenix.org|access-date=6 December 2014|archive-date=25 July 2011|archive-url=https://web.archive.org/web/20110725000112/http://alexisphoenix.org/adakaleh.php|url-status=dead}}</ref> The island was submerged during the construction of the Iron Gates hydroelectric plant in 1970.]]

*Ada Kaleh Island
*Ostrovul Mare, Gogoșu
*Balta Ialomiței
*Belene Island
*Csepel Island
*Donauinsel
*Great Brăila Island
*Great War Island
*Island of Mohács
*Kozloduy Island
*Margaret Island
*Ostrovo (Kostolac)
*Ostrovul Ciocănești
*Ostrovul Mare, Islaz
*Ribarsko Ostrvo, Novi Sad
*Island of Šarengrad
*Szigetköz
*Island of Szentendre
*Vardim Island
*Island of Vukovar
*Žitný ostrov

===Sectioning===<!-- This section is linked from [[Place:Bratislava|Bratislava]] -->
*Upper Section: From spring to Devín Gate, at the border of Austria and Slovakia. Danube remains a characteristic mountain river until Passau, with average bottom gradient 0.0012% (12 ppm), from Passau to Devín Gate the gradient lessens to 0.0006% (6 ppm).
*Middle Section: From Devín Gate to Iron Gate, at the border of Serbia and Romania. The riverbed widens and the average bottom gradient becomes only 0.00006% (0.6 ppm).
*Lower Section: From Iron Gate to Sulina, with average gradient as little as 0.00003% (0.3 ppm).

==Modern navigation==
[[File:Parliament Budapest Hungary.jpg|thumb|The Danube in Budapest]]
[[File:DanubedeltaSulinaarm2.jpg|thumb|Fisherman in the Danube Delta]]
[[File:Freight-ship-danube-320x240.ogg|thumb|Freight ship on the Danube near Vienna]]
The Danube is navigable by ocean ships from the Black Sea to Brăila in Romania (the maritime river sector), and further on by river ships to Kelheim, Bavaria, Germany; smaller craft can navigate further upstream to Ulm, [[Place:Württemberg|Württemberg]], Germany. About 60 of its tributaries are also navigable.

Since the completion of the German Rhine–Main–Danube Canal in 1992, the river has been part of a trans-European waterway from Rotterdam on the North Sea to Sulina on the Black Sea, a distance of {{convert|3500|km|sp=us|abbr=on}}. 
In 1994 the Danube was declared one of ten Pan-European transport corridors, routes in Central and Eastern Europe that required major investment over the following ten to fifteen years.{{cn|date=November 2022}} The amount of goods transported on the Danube increased to about 100 million tons in 1987. 
In 1999, transport on the river was made difficult by the NATO bombing of three bridges in Serbia during the Kosovo War. Clearance of the resulting debris was completed in 2002, and a temporary pontoon bridge that hampered navigation was removed in 2005.{{cn|date=November 2022}}

At the Iron Gate, the Danube flows through a [[Earth:Canyon|gorge]] that forms part of the boundary between Serbia and Romania; it contains the Iron Gate I Hydroelectric Power Station dam, followed at about {{convert|60|km|sp=us|abbr=on}} downstream (outside the gorge) by the Iron Gate II Hydroelectric Power Station. On 13 April 2006, a record peak discharge at Iron Gate Dam reached {{convert|15400|m3/s|sp=us|abbr=on}}.

There are three artificial waterways built on the Danube: the Danube-Tisa-Danube Canal (DTD) in the Banat and Bačka regions (Vojvodina, northern province of Serbia); the {{convert|64|km|sp=us|abbr=on}} Danube-Black Sea Canal, between Cernavodă and Constanța (Romania) finished in 1984, shortens the distance to the Black Sea by {{convert|400|km|sp=us|abbr=on}}; the Rhine–Main–Danube Canal is about {{convert|171|km|sp=us|abbr=on}}, finished in 1992, linking the North Sea to the Black Sea.<ref>{{Cite web|url=http://ines-danube.info/goto.php?target=file_1442_download&client_id=viailias4|title=Danube navigation at a glance}}</ref> A Danube-Aegean canal has been proposed.<ref>{{Cite web |last=Tzimas |first=Stavros |title=Chinese interests could make plan to link Danube and Aegean a reality {{!}} eKathimerini.com |url=https://www.ekathimerini.com/economy/221159/chinese-interests-could-make-plan-to-link-danube-and-aegean-a-reality/ |access-date=2022-07-11 |website=www.ekathimerini.com |language=English}}</ref>

==Piracy==
In 2010–12, shipping companies, especially from Ukraine, claimed that their vessels suffered from "regular pirate attacks" on the Serbian and the Romanian stretches of the Danube.<ref>{{cite web|url=http://www.jutarnji.hr/rijecni-gusari-u-srbiji-pljackaju-hrvatske-brodove--zadnja-zrtva-brod--quot-sloga-quot--sisackog--quot-dunavskog-lloyda-quot-/980402/|title=Riječni gusari u Srbiji pljačkaju hrvatske brodove|language=hr|first=Mate|last=Piškor|date=12 October 2011}}</ref><ref>{{cite web |url=http://un.ua/eng/article/369989.html |title=Ukrainian Danube Shipping Company Says Its Ships Are Being Attacked Frequently in Romanian Part Of River Danube |publisher=Un.ua |access-date=11 June 2012 |archive-url=https://web.archive.org/web/20120114032713/http://un.ua/eng/article/369989.html |archive-date=14 January 2012 |url-status=dead }}</ref><ref>{{cite web|url=https://gazeta.ua/articles/np/_ukrajinski-korabli-vse-chastishe-stayut-zhertvami-rumunskih-pirativ/419063|title=Українські кораблі все частіше стають жертвами румунських піратів|website=Gazeta.ua|trans-title=Romanian Pirates Attack Ukrainian Ships More Frequently|language=uk|date=20 January 2012|first=Олена|last=Гордієва}}</ref> However, the transgressions may not be considered acts of piracy, as defined according to the United Nations Convention on the Law of the Sea, but rather instances of "river robbery".<ref>[http://www.rivercruiseinfo.com/content/pirates-lower-danube Pirates on the lower Danube] {{Webarchive|url=https://web.archive.org/web/20131214175158/http://www.rivercruiseinfo.com/content/pirates-lower-danube |date=14 December 2013 }} at rivercruiseinfo.com</ref>

On the other hand, media reports say the crews on transport ships often steal and sell their own cargo and then blame the plundering on "pirates", and the alleged attacks are not piracy but small-time contraband theft along the river.<ref>[http://www.rferl.org/content/romania_danube_river_pirates_ukraine/24474067.html Reports Of 'Pirates Of The Danube' Get The Old Heave-Ho] at Radio Free Europe</ref>

==Danube Delta==
The Danube Delta ({{lang-ro|Delta Dunării}} {{IPA-ro|ˈdelta ˈdunərij|pron}}; {{lang-uk|Дельта Дунаю|translit=Del'ta Dunayu}}) is the largest river delta in the [[Social:European Union|European Union]]. The greater part of the Danube Delta lies in Romania (Tulcea county), while its northern part, on the left bank of the Chilia arm, is situated in Ukraine (Odesa Oblast). The approximate surface is {{convert|4152|km2|sp=us|abbr=on}}, of which {{convert|3446|km2|sp=us|abbr=on}} are in Romania. If one includes the lagoons of Razim-Sinoe ({{convert|1015|km2|sp=us|abbr=on}} of which {{convert|865|km2|sp=us|abbr=on}} water surface), which are located south of the delta proper, but are related to it geologically and ecologically (their combined territory is part of the World Heritage Site), the total area of the Danube Delta reaches {{convert|5165|km2|sp=us|abbr=on}}.

The Danube Delta is also the best-preserved river delta in Europe, a UNESCO World Heritage Site (since 1991) and a Ramsar Site. Its lakes and marshes support 45 freshwater fish species. Its wetlands support vast flocks of migratory birds of over 300 species, including the endangered [[Biology:Pygmy cormorant|pygmy cormorant]] (''Phalacrocorax pygmaeus''). These are threatened by rival canalization and drainage schemes such as the Bystroye Canal.<ref>{{cite book|url=https://www.unece.org/fileadmin/DAM/env/eia/documents/inquiry/Rom.1.pdf|title=Documentation on the likely significant transboundary impact of the Ukrainian deep-water navigation canal Danube-black sea in the context of Espoo Convention, 1991|year=2005|author=Staras, Mircea|publisher=Danube Delta National Institute|publication-date=February 2005|location=Tulcea, Romania|archive-date=3 August 2020|archive-url=https://web.archive.org/web/20200803080734/https://www.unece.org/fileadmin/DAM/env/eia/documents/inquiry/Rom.1.pdf|access-date=20 September 2020|url-status=live}}</ref>

==2022 heat wave==
In 2022, there was a major [[Earth:Heat wave|heat wave]] in Europe. As a result, there was less water flowing in the rivers. As the water level decreased, a number of ship wrecks from [[Social:World War II|World War II]] emerged in the Danube River. Many of the ships were from [[Place:Nazi Germany|Nazi Germany]]'s Black Sea Fleet and had been scuttled to stop them from falling into enemy hands.<ref>{{cite news | url=https://www.nytimes.com/2022/08/23/world/europe/danube-river-shipwrecks-drought.html | title=Europe's Rivers, Starved by Drought, Reveal Shipwrecks, Relics and Bombs | work=The New York Times | date=23 August 2022 | last1=Schuetze | first1=Christopher F.}}</ref>

==International cooperation==
===Ecology and environment===
[[File:Pelicani din Delta Dunarii.PNG|thumb|right|Pelicans in the Danube Delta, Romania]]

The International Commission for the Protection of the Danube River (ICPDR) is an organization that consists of 14 member states (Germany, Austria, the Czech Republic, Slovakia, Slovenia, Hungary, Croatia, Bosnia and Herzegovina, Serbia, Bulgaria, Romania, Moldova, Montenegro, and Ukraine) and the [[Social:European Union|European Union]]. The commission, established in 1998, deals with the whole Danube river basin, which includes tributaries and groundwater resources. Its goal is to implement the Danube River Protection Convention by promoting and coordinating sustainable and equitable water management, including conservation, improvement, and rational use of waters and the implementation of the EU Water Framework Directive and the Danube Strategy.

===Navigation===
The Danube Commission is concerned with the maintenance and improvement of the river's navigation conditions. It was established in 1948 by seven countries bordering the river. Members include representatives from Austria, Bulgaria, Croatia, Germany, Hungary, Moldova, Slovakia, Romania, Russia, Ukraine, and Serbia; it meets regularly twice a year. It also convenes groups of experts to consider items provided for in the commission's working plans.

The commission dates to the Paris Conferences of 1856 and 1921, which established for the first time an international regime to safeguard free navigation on the Danube. Today the Commission include riparian and non-riparian states.

==Geology==
[[File:Evening at Danube gorge.jpg|thumb|right| Iron Gates, Serbia-Romania border]]
[[File:Dam Serbia Djerdap 2.jpg|thumb|right|Iron Gate II Hydroelectric Power Station, Romania-Serbia]]
Although the headwaters of the Danube are relatively small today, geologically, the Danube is much older than the [[Place:Rhine|Rhine]], with which its catchment area competes in today's southern Germany. This has a few interesting geological complications. Since the Rhine is the only river rising in the [[Place:Alps|Alps]] mountains which flows north towards the North Sea, an invisible line beginning at Piz Lunghin divides large parts of southern Germany, which is sometimes referred to as the European Watershed.

Before the last [[Earth:Ice age|ice age]] in the [[Earth:Pleistocene|Pleistocene]], the Rhine started at the southwestern tip of the Black Forest, while the waters from the Alps that today feed the Rhine were carried east by the so-called ''Urdonau'' (original Danube). Parts of this ancient river's bed, which was much larger than today's Danube, can still be seen in (now waterless) canyons in today's landscape of the Swabian Alb. After the Upper Rhine valley had been eroded, most waters from the Alps changed their direction and began feeding the Rhine. Today's upper Danube is but a meek reflection of the ancient one.
[[File:Danube Iron Gorge La Cazane.JPG|thumb|The Iron Gate, on the Serbian-Romanian border (Iron Gates natural park and Đerdap national park)]]
Since the Swabian Alb is largely shaped of porous [[Earth:Limestone|limestone]], and since the Rhine's level is much lower than the Danube's, today subsurface rivers carry much water from the Danube to the Rhine. On many days in the summer, when the Danube carries little water, it completely oozes away noisily into these underground channels at two locations in the Swabian Alb, which are referred to as the Donauversickerung (Danube Sink). Most of this water resurfaces only {{convert|12|km|mi|sp=us|abbr=on}} south at the Aachtopf, Germany's wellspring with the highest flow, an average of {{convert|8500|L/s|cuft/s|sp=us|abbr=on}}, north of [[Earth:Lake Constance|Lake Constance]]—thus feeding the Rhine. The European Water Divide applies only for those waters that pass beyond this point, and only during the days of the year when the Danube carries enough water to survive the sinkholes in the Donauversickerung.

Since such large volumes of underground water erode much of the surrounding limestone, it is estimated that the Danube upper course will one day disappear entirely in favor of the Rhine, an event called [[Earth:Stream capture|stream capturing]].

The hydrological parameters of Danube are regularly monitored in Croatia at Batina, Dalj, Vukovar and Ilok.<ref>{{cite web | url = http://hidro.hr/hidro_e.php?id=hidro&param=Podaci_e | title = Daily hydrological report | publisher = State Hydrometeorological Bureau of the Republic of Croatia | access-date = 9 September 2010 | archive-date = 30 May 2010 | archive-url = https://web.archive.org/web/20100530062812/http://hidro.hr/hidro_e.php?id=hidro&param=Podaci_e | url-status = dead }}</ref>

==History==
<!-- This section is linked from [[Biography:Marcus Aurelius|Marcus Aurelius]] -->
[[File:Guerre d'orient, combat sur le Danube.jpg|thumb|Combat between Russian and Turkish forces on the Danube in 1854, during the Crimean War (1853–1856)]]
The Danube basin was the site of some of the earliest human cultures. The [[History:Danubian culture|Danubian Neolithic]] cultures include the Linear Pottery cultures of the mid-Danube basin. Many sites of the sixth-to-third millennium BCE [[History:Vinča culture|Vinča culture]], (Vinča, Serbia) are sited along the Danube. The third millennium BCE Vučedol culture (from the Vučedol site near Vukovar, Croatia) is famous for its ceramics.

Darius the Great, [[Place:Achaemenid Empire|king of Persia]], crossed the river in the late 6th century BCE to invade European Scythia and to subdue the [[History:Scythians|Scythians]].

Alexander the Great defeated the Triballian king Syrmus and the northern barbarian Thracian and Illyrian tribes by advancing from Macedonia as far as the Danube in 336 BCE.

Under the Romans, the Danube formed the border of the Empire with the tribes to the north almost from its source to its mouth. At the same time, it was a route for the transport of troops and the supply of settlements downstream. From 37 CE to the reign of the Emperor Valentinian I (364–375) the Danubian Limes was the northeastern border of the Empire, with occasional interruptions such as the fall of the Danubian Limes in 259. The crossing of the Danube into Dacia was achieved by the ''Imperium Romanum'', first in two battles in 102 and then in 106 after the construction of a bridge in 101 near the garrison town of Drobeta at the Iron Gate. This victory over Dacia under Decebalus enabled the Province of Dacia to be created, but in 271 it was abandoned by emperor Aurelian.

Avars used the river as their southeastern border in the 6th century.

<gallery widths="200px" heights="160px">
File:Trajan's Bridge Across the Danube, Modern Reconstruction.jpg|The oldest bridge across the Danube, constructed by Apollodorus of Damascus between 103 and 105 [[Common Era|CE]], directed by Trajan, modern Serbia and Romania.
File:Mária Valéria´s bridge.jpg|At Esztergom and Štúrovo, the Danube separates Hungary from Slovakia.
File:Vena 06.jpg|The Danube in [[Place:Vienna|Vienna]]
File:Danube at belene.jpg|The Danube between Belene and Belene Island, Bulgaria
File:Frozen Danube Reichsbrücke.JPG|A look upstream from the Donauinsel in Vienna, Austria during an unusually cold winter (February 2006). A frozen Danube usually occurs just once or twice in a lifetime.
File:Bratislavaminorflood.jpg|[[Place:Bratislava|Bratislava]] does not usually suffer major floods, but the Danube sometimes overflows its right bank.
</gallery>

===Ancient cultural perspectives of the lower Danube===
Part of the rivers Danubius or Istros was also known as (together with the Black Sea) the ''Okeanos'' in ancient times, being called the ''Okeanos Potamos'' (Okeanos River). The lower Danube was also called the ''Keras Okeanoio'' (Gulf or Horn of Okeanos) in the ''Argonautica'' by Apollonius Rhodos (Argon. IV. 282). <!-- [needs not only cites but some explanation of relevance, particularly for references to Lithuanian linguistics]{{Or|date=July 2009}}{{Citation needed|date=July 2009}}.-->

At the end of the ''Okeanos Potamos'', is the holy island of Alba (Leuke, Pytho Nisi, Isle of Snakes), sacred to the Pelasgian (and later, Greek) Apollo, greeting the sun rising in the east. Hecateus Abderitas refers to Apollo's island from the region of the Hyperboreans, in the Okeanos. It was on Leuke, in one version of his legend, that the hero Achilles was buried (to this day, one of the mouths of the Danube is called Chilia). Old Romanian folk songs recount a white monastery on a white island with nine priests.<ref name=Densusianu>[http://www.pelasgians.org/ ''Dacia Preistorica''] {{Webarchive|url=https://web.archive.org/web/20080707015920/http://www.pelasgians.org/ |date=7 July 2008 }}, Nicolae Densusianu (1913).</ref>

===Rivalry along the Danube===

Between the late 14th and late 19th centuries, the [[Place:Ottoman Empire|Ottoman Empire]] competed first with the [[History:Kingdom of Serbia (medieval)|Kingdom of Serbia]], [[Place:Second Bulgarian Empire|Second Bulgarian Empire]], [[History:Kingdom of Hungary|Kingdom of Hungary]], Principality of Wallachia, Principality of Moldavia and later with the Austrian Habsburgs, [[Place:Polish–Lithuanian Commonwealth|Polish–Lithuanian Commonwealth]], and [[Place:Russian Empire|Russian Empire]] for controlling the Danube (''Tuna'' in [[Social:Turkish language|Turkish]]), which became the northern border of the Ottoman Empire for centuries. Many of the Ottoman–Hungarian Wars (1366–1526) and [[History:Ottoman–Habsburg wars|Ottoman–Habsburg wars]] (1526–1791) were fought along the river.

The most important wars of the Ottoman Empire along the Danube include the Battle of Nicopolis (1396), the Siege of Belgrade (1456), the Battle of Mohács (1526), the first Turkish Siege of Vienna (1529), the Siege of Esztergom (1543), the Long War (1591–1606), the Battle of Vienna (1683), the Great Turkish War (1683–1699), the Crimean War (1853–1856) and the Russo-Turkish War (1877–1878).

===Second World War===
During the 2011 renovation of the Margaret Bridge, [[Place:Budapest|Budapest]], human remains were discovered. The mostly Jewish remains were victims of the far-right Arrow Cross Party, who briefly governed Hungary from 1944.<ref>{{cite news |agency=The Associated Press|title=Hungary buries remains of Holocaust victims executed by Nazis on banks of the Danube River |url=https://nationalpost.com/news/world/hungary-buries-remains-of-holocaust-victims-executed-by-nazis-on-banks-of-the-danube-river |website=National Post |access-date=16 February 2022 |language=en |date=15 April 2016}}</ref>

==Economics==
===Drinking water===
Along its course, the Danube is a source of drinking water for about 20 million people.<ref>{{Cite web|title=About Us {{!}} ICPDR – International Commission for the Protection of the Danube River|url=https://www.icpdr.org/main/icpdr/about-us|access-date=2021-02-05|website=www.icpdr.org}}</ref><ref>{{Cite web|last=|first=|date=|title=Blue River|url=https://wwf.panda.org/discover/knowledge_hub/where_we_work/black_sea_basin/danube_carpathian/our_solutions/freshwater/danube_river_basin/?|url-status=live|archive-url=https://web.archive.org/web/20210412152545/https://wwf.panda.org/discover/knowledge_hub/where_we_work/black_sea_basin/danube_carpathian/our_solutions/freshwater/danube_river_basin/? |archive-date=12 April 2021 |access-date=2021-02-05|website=wwf.panda.org}}</ref> In Baden-Württemberg, Germany, almost 30 percent (as of 2004) of the water for the area between [[Place:Stuttgart|Stuttgart]], Bad Mergentheim, Aalen and Alb-Donau (district) comes from purified water of the Danube. Other cities such as Ulm and Passau also use some water from the Danube.

In Austria and Hungary, most water is drawn from ground and spring sources, and only in rare cases is water from the Danube used. Most states also find it too difficult to clean the water because of extensive pollution; only parts of Romania where the water is cleaner still obtain drinking water from the Danube on a regular basis.<ref>{{cite web |url=http://www.iawd.at/cms/pages/en/the-danube.php |title=The Danube |publisher=International Association of Water Supply Companies in the Danube River Catchment Area |access-date=28 July 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120519200631/http://www.iawd.at/cms/pages/en/the-danube.php |archive-date=19 May 2012  }}</ref>

===Navigation and transport===
[[File:Fischerzille LüA 10 m Donau bei Greifenstein Niederösterreich.jpg|thumb|right|Fishing from a Zille on the Danube in Lower Austria, 1982]]

In the 19th century, the Danube was an important waterway but was, as ''The Times'' of London put it, "annually swept by ice that will lift a large ship out of the water or cut her in two as if she were a carrot."<ref>{{Cite web|url=https://www.thetimes.co.uk/|title=The Times & The Sunday Times|website=www.thetimes.co.uk}}</ref>

Today, as "Corridor VII" of the [[Social:European Union|European Union]], the Danube is an important transport route. Since the opening of the Rhine–Main–Danube Canal, the river connects the Port of Rotterdam and the industrial centers of Western Europe with the Black Sea and, also, through the Danube&nbsp;– Black Sea Canal, with the Port of Constanța.

The waterway is designed for large-scale inland vessels ({{nowrap|110 × 11.45 m}}) but it can carry much larger vessels on most of its course. The Danube has been partly canalized in Germany (5 locks) and Austria (10 locks). Proposals to build a number of new locks to improve navigation have not progressed, due in part to environmental concerns.

Downstream from the Freudenau locks in Vienna, canalization of the Danube was limited to the Gabčíkovo dam and locks near Bratislava and the two double Iron Gate locks in the border stretch of the Danube between Serbia and Romania. These locks have larger dimensions. Downstream of the Iron Gate, the river is free flowing all the way to the Black Sea, a distance of more than {{convert|860|km|mi}}.

The Danube connects with the Rhine–Main–Danube Canal at Kelheim, with the Donaukanal in Vienna, and with the Danube–Black Sea Canal at Cernavodă.

Apart from a couple of secondary navigable branches, the only major navigable rivers linked to the Danube are the Drava, Sava and Tisa. In Serbia, a canal network also connects to the river; the network, known as the Danube–Tisa–Danube Canals, links sections downstream.

In the Austrian and German sections of the Danube, a type of flat-bottomed boat called a [[Engineering:Zille (boat)|Zille]] was developed for use along the river. Zillen are still used today for fishing, ferrying, and other transport of goods and people in this area.

===Fishing===
The importance of fishing on the Danube, which was critical in the [[History:Middle Ages|Middle Ages]], has declined dramatically. Some fishermen are still active at certain points on the river, and the Danube Delta still has an important industry. However, some of the river's resources have been managed in an environmentally unsustainable manner in the past, leading to damage by pollution, alterations to the channel, and major infrastructure development, including large hydropower dams.<ref>{{cite book |last=Holcik |first=Juraj |date=1989 |title=The freshwater fishes of Europe Vol.I Part II General introduction to fishes|location=Wiesbaden |publisher=Aula Verlag}}</ref>

The [[Biology:Sturgeon|sturgeon]] stocks associated with the Danube River basin have, over the centuries, formed the basis of a large and significant commercial fishery, renowned throughout the world. The construction of the dams, besides overfishing and river pollution, has a significant role in sturgeon population decline because it creates a barrier for fish migratory species that usually spawn in the upper parts of the river.<ref>{{cite book |last1=Hensel |first1=K |last2=Holcik |first2=J |date=1997 |title=Past and current status of sturgeons in the upper and middle Danube River.|url=https://www.researchgate.net/publication/226596320}}</ref> The spawning areas of migratory fishes species has been dramatically reduced by the construction of hydropower and navigation systems at Iron Gates I (1974) and Iron Gates II (1984).<ref>{{cite web |author=Corda |date=1988 |title=Iron gates II design and performance of dams- geotechnical considerations |url=https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=1503&context=icchge |publisher=International Conference on Case Histories in Geotechnical Engineering |format=PDF}}</ref> The initial design of these dams has not included any fish passage facility.<ref>{{cite conference |url=https://www.danube-iad.eu/docs/IAD39_Proceeding_Book_lores.pdf |title=Have sturgeons a future in the Danube River?  |author=Suciu Radu, Guti Gabor |year=2012 |conference=39th IAD Conference: Living Danube |location=Szentendre, Hungary }}</ref> The possibility of building a human-made fish pass enabling migration for fish species including the sturgeon, is currently under review by projects such as We Pass.<ref>{{cite AV media |date= 11 Nov 2019 |title= We Pass – Facilitating Fish Migration and Conservation at the Iron Gates |language=en |url=https://www.youtube.com/watch?v=81i25THmBws  |archive-url=https://ghostarchive.org/varchive/youtube/20211215/81i25THmBws |archive-date=2021-12-15 |url-status=live|publisher=ICPDR }}{{cbignore}}</ref>

The Upper Danube [[Earth:Ecoregion|ecoregion]] alone has about 60 fish species and the Lower Danube–Dniester ecoregion has about twice as many.<ref name=FEW>Hales, J. (2013). ''[http://www.feow.org/ecoregions/details/417 Upper Danube]''. Freshwater Ecoregions of the World. Retrieved 25 February 2013.</ref> Among these are an exceptionally high diversity of sturgeon, a total of six species (beluga, [[Biology:Russian sturgeon|Russian sturgeon]], [[Biology:Bastard sturgeon|bastard sturgeon]], [[Biology:Sterlet|sterlet]], [[Biology:Starry sturgeon|starry sturgeon]] and [[Biology:European sea sturgeon|European sea sturgeon]]), but these are all threatened and have largely–or entirely in the case of the European sea sturgeon–disappeared from the river.<ref name=FEW/> The [[Biology:Huchen|huchen]], one of the largest species of salmon, is [[Biology:Endemism|endemic]] to the Danube basin, but has been [[Earth:Introduced species|introduced]] elsewhere by humans.<ref>{{FishBase | genus = Hucho | species = hucho | month = February | year = 2013}}</ref>

===Tourism===
[[File:Wachau (3).JPG|thumb|Wachau Valley near Spitz, Austria]]
Important tourist and natural spots along the Danube include the Wachau Valley, the Nationalpark Donau-Auen in Austria, Gemenc in Hungary, the Naturpark Obere Donau in Germany, Kopački rit in Croatia, Iron Gate in Serbia and Romania, the Danube Delta in Romania, and the Srebarna Nature Reserve in Bulgaria.

Also, leisure and travel cruises on the river are of significance. Besides the often frequented route between Vienna and Budapest, some ships even go from Passau in Germany to the Danube Delta and back. During the peak season, more than 70 cruise liners are in use on the river, while the traffic-free upper parts can only be discovered with canoes or boats.

The Danube region is not only culturally and historically of importance, but also due to its fascinating landmarks and sights important for the regional tourism industry. With its well established infrastructure regarding cycling, hiking, and travel possibilities, the region along the Danube attracts every year an international clientele. In Austria alone, there are more than 14&nbsp;million overnight stays and about 6.5&nbsp;million arrivals per year.<ref name="kaiserundkoenige">{{cite web|url=http://www.strassederkaiserundkoenige.at/fileadmin/user_upload/Brosch%C3%BCren/ARGE_Donau_%C3%96sterreich2013.pdf |title=Press release of the "ARGE Donau Österreich" |access-date=1 April 2014 |language=de |url-status=dead |archive-url=https://web.archive.org/web/20140313154833/http://www.strassederkaiserundkoenige.at/fileadmin/user_upload/Brosch%C3%BCren/ARGE_Donau_%C3%96sterreich2013.pdf |archive-date=13 March 2014  }}</ref>

The Danube Banks in [[Place:Budapest|Budapest]] are a part of Unesco World Heritage sites, they can be viewed from a number of sightseeing cruises offered in the city.

The Danube Bend is also a popular tourist destination.

====Danube Bike Trail====
[[File:Donauradweg Schloegener Schlinge - Aschach.jpg|thumb|The Danube Bike Trail running along the ''Schlögener Schlinge'']]
[[File:LinzDonaulaende.jpg|thumb|The Danube Bike Trail leading through the city of Linz]]
The Danube Bike Trail (also called Danube Cycle Path or the ''Donauradweg'') is a bicycle trail along the river. Especially the parts through Germany and Austria are very popular, which makes it one of the 10 most popular bike trails in Germany.<ref>{{cite web |title=''Die ADFC-Radreiseanalyse 2013'' – Zahlen, Daten und Fakten |url=http://www.adfc.de/radreiseanalyse/die-adfc-radreiseanalyse-2013 |access-date=12 March 2014 |language=de |archive-url=https://web.archive.org/web/20170618233337/http://www.adfc.de/radreiseanalyse/die-adfc-radreiseanalyse-2013 |archive-date=18 June 2017 |url-status=dead }}</ref>

The Danube Bike Trail starts at the origin of the Danube and ends where the river flows into the Black Sea. It is divided into four sections:
#Donaueschingen–Passau ({{Convert|559|km|mi|abbr=on|disp=or}})
#Passau–[[Place:Vienna|Vienna]] ({{Convert|340|km|mi|abbr=on|disp=or}})
#[[Place:Vienna|Vienna]]–[[Place:Budapest|Budapest]] ({{Convert|306|km|mi|abbr=on|disp=or}})
#[[Place:Budapest|Budapest]]–Black Sea ({{Convert|1670|km|mi|abbr=on|disp=or}})

====Sultans Trail====
The Sultans Trail is a hiking trail that runs along the river between [[Place:Vienna|Vienna]] and [[Place:Smederevo|Smederevo]] in Serbia. From there the Sultans Trail leaves the Danube, terminating in Istanbul. Sections along the river are as follows.
#[[Place:Vienna|Vienna]]–[[Place:Budapest|Budapest]] ({{Convert|323|km|mi|abbr=on|disp=or}})
#[[Place:Budapest|Budapest]]–[[Place:Smederevo|Smederevo]] ({{Convert|595|km|mi|abbr=on|disp=or}})

====Donausteig====
[[File:Donausteig Rastplatz.jpg|thumb|Resting area along the ''Donausteig'' hiking trail near Bad Kreuzen]]
In 2010, the Donausteig, a hiking trail from Passau to Grein, was opened. It is {{convert|450|km|mi|sp=us|abbr=on}} long and it is divided into 23 stages. The route passes through five Bavarian and 40 Austrian communities. A landscape and viewpoints, which are along the river, are the highlights of the ''Donausteig''.<ref>{{ cite web |title=Donausteig |url= http://www.traildino.com/trace/continents-Europe/countries-Austria/trails-Donausteig |website=Traildino.com |access-date=1 April 2014}}</ref>

====The Route of Emperors and Kings====
The Route of Emperors and Kings is an international touristic route leading from Regensburg to Budapest, calling in Passau, Linz and Vienna.<ref>{{Cite web|url=https://www.routeofemperorsandkings.com/|title=Welcome|website=Straße der Kaiser und Könige}}</ref> The international consortium ''ARGE Die Donau-Straße der Kaiser und Könige'', comprising ten tourism organisations, shipping companies, and cities, strives for the conservation and touristic development of the Danube region.<ref name="kaiserundkoenige" />

In medieval Regensburg, with its maintained old town, stone bridge and cathedral, the Route of Emperors and Kings begins. It continues to Engelhartszell, with the only Trappist monastery in Austria. Further highlight-stops along the Danube, include the "Schlögener Schlinge", the city of Linz, which was [[Place:European Capital of Culture|European Capital of Culture]] in 2009 with its contemporary art richness, the Melk Abbey, the university city of Krems and the cosmopolitan city of Vienna. Before the Route of Emperors and Kings ends, you pass Bratislava and Budapest, the latter of which was seen as the twin town of Vienna during the times of the [[Place:Austria-Hungary|Austro-Hungarian Empire]].
Since [[History:Ancient Rome|ancient Roman times]], famous emperors and their retinue traveled on and along the Danube and used the river for travel and transportation. While traveling on the mainland was quite exhausting, most people preferred to travel by ship on the Danube. So the Route of Emperors and Kings was the setting for many important historical events, which characterize the Danube up until today.

The route got its name from the Holy Roman Emperor Frederick I of Barbarossa and the [[Religion:Crusades|crusaders]] as well as from Richard I of England who had been jailed in the Dürnstein Castle, which is situated above the Danube. The most imperial journeys throughout time were those of the Habsburg family. Once crowned in Frankfurt, the emperors ruled from Vienna and also held in Regensburg the Perpetual Diet of Regensburg. Many famous castles, palaces, residences, and state-run convents were built by the Habsburger along the river. Nowadays they still remind us of the bold architecture of the "Donaubarock".

Today, people can not only travel by boat on the Danube but also by train, by bike on the Danube Bike Trail or walk on the "Donausteig" and visit the UNESCO World Heritage cities of Regensburg, Wachau and Vienna.<ref>{{cite web |title=The Route of Emperors and Kings |url=https://www.bavaria.by/the-route-of-emperors-and-kings |access-date=29 March 2014 |website=bavaria.by}}</ref>

==Important national parks==
* Naturpark Obere Donau (Germany)
* Donauauen zwischen Neuburg und Ingolstadt (Germany) – [https://web.archive.org/web/20111023161527/http://danubemap.eu/donauauwald map]
* Nature protection area Donauleiten (Germany)
* Nationalpark Donau Auen (Austria) – [https://web.archive.org/web/20111023161522/http://danubemap.eu/donauauen map]
* Chránená krajinná oblasť Dunajské luhy (Slovakia) – [https://web.archive.org/web/20111021055315/http://danubemap.eu/dunajskeluhy map]
* Danube-Ipoly National Park (Hungary) – [https://web.archive.org/web/20111021055252/http://danubemap.eu/dunaipoly map]
* Danube-Drava National Park (Hungary) – [https://web.archive.org/web/20111023101801/http://danubemap.eu/dunadrava map]
* Naturalpark Kopački Rit (Croatia) – [https://web.archive.org/web/20111023110151/http://danubemap.eu/kopackirit map]
* Gornje Podunavlje Nature Reserve (Serbia) – [https://web.archive.org/web/20111024011005/http://danubemap.eu/podunavlje map]
* Fruška Gora National Park (Serbia)
* Koviljsko-petrovaradinski rit Nature Reserve (Serbia)
* Great War Island Nature Reserve (Serbia)
* Đerdap National park (Serbia)
* Iron Gates Natural Park (Romania)
* Persina Nature Park (Bulgaria) – [https://web.archive.org/web/20111023161537/http://danubemap.eu/persina map]
* Kalimok-Brushlen Protected Site (Bulgaria) – [https://web.archive.org/web/20111023110144/http://danubemap.eu/kalimok map]
* Srebarna Nature Reserve (Bulgaria) – [https://web.archive.org/web/20111024012109/http://danubemap.eu/srebarna map]
* Măcin Mountains Natural Park (Romania)
* Balta Mică a Brăilei Natural Park (Romania)
* Danube Delta Biosphere Reserve (Romania) – [https://web.archive.org/web/20111023101756/http://danubemap.eu/delta map]
* Danube Biosphere Reserve in Ukraine

<gallery widths="200px" heights="160px">
File:Gornje Podunavlje.jpg|Gornje Podunavlje Special Nature Reserve in Serbia
File:Golubaccas.jpg|Golubac Fortress in Đerdap National park, Serbia
</gallery>

==In popular culture==
{{prose|date=May 2012}}
[[File:Danube Landscape near Regensburg.JPG|thumb|right|16th-century Danube landscape near Regensburg, by Albrecht Altdorfer – a member of the Danube school]]

* The Danube is mentioned in the title of a famous waltz by Austrian composer Johann Strauss, ''The Blue Danube Waltz'' (''On the Beautiful Blue Danube''). This piece is well known across the world and is also used widely as a lullaby. ''The Waves of the Danube'' ({{lang-ro|Valurile Dunării}}) is a waltz by the Romanian composer Iosif Ivanovici (1845–1902); as the Anniversary '''Song''', it has been performed by many vocalists, such as Al Jolson, Rosemary Clooney, Vera Lynn, Tom Jones, and countless others. [It is most commonly known as the Anniversary '''Waltz''', though that is actually a different song and melody.] Joe Zawinul wrote a symphony about the Danube called ''Stories of the Danube''. It was performed for the first time at the 1993 Bruckner festival, at [[Place:Linz|Linz]].
* The Danube figures prominently in the Bulgarian National Anthem, as a symbolic representation of the country's natural beauty. In Lithuanian folklore songs, the appearance of Danube (Dunojus, Dunojėlis) is more common than the appearance of the longest Lithuanian river Neman.
* The German tradition of landscape painting, the Danube school, was developed in the Danube valley in the 16th century.{{Citation needed|date=May 2021}}
* One of Claudio Magris's masterpieces is called ''Danube'' ({{ISBN|1-86046-823-3}}). The book, published in 1986, is a large cultural-historical essay, in which Magris travels the Danube from the first sources to the delta, tracing the rich European ethnic and cultural heritage, literary and ideological past and present along the way.
* ''[https://books.google.com/books?id=xqR_BAAAQBAJ The Great Danube Adventure]''(1838) is an epic travel diary.
* Jules Verne's ''The Danube Pilot'' (1908) (''Le Pilote du Danube'') depicts the adventures of fisherman Serge Ladko as he travels down the river.
* In the ''Star Trek'' universe, the ''Danube''-class runabout is a type of [[Engineering:Starship|starship]] used by the Federation Starfleet, most notably{{according to whom|date=March 2022}} in the ''Deep Space Nine'' series.
* Miklós Jancsó's film the ''Blue Danube Waltz'' (1992)
*Algernon Blackwood's short story "The Willows" mostly takes place on the river.
{{Clear}}

==See also==
* Danube Monarchy
* Danubian Principalities
* List of cities and towns on Danube river
* 2006 European floods
* ''Between the Woods and the Water'', a travel book telling of a Danubian journey in 1934
* ''The Ister'', 2004 film
* Executive Agency for Exploration and Maintenance of the Danube River
* List of crossings of the Danube
* Steamboats on the Danube
*Black Sea drainage basin

== References ==
{{Reflist}}

==External links==
{{Wikivoyage}}
{{Commons|Danube}}
{{EB1911 Poster|Danube}}
* [http://pdf.wri.org/watersheds_2000/watersheds_europe_p2_38.pdf Danube watershed map and information from the World Resources Institute]
* [http://danubepanorama.net/en/ Danube Panorama Project]
* [http://danube.at.ua/ сайт о Дунае] {{in lang|ru}}
* [http://www.werow.com/en/guide/donau Danube and the sport of rowing]
* [https://www.flickr.com/groups/danube_river/pool/ Danube image pool on Flickr]
* [http://www.danube-river.org/ Danube Tourist Commission] {{Webarchive|url=https://web.archive.org/web/20220206024032/http://www.danube-river.org/ |date=6 February 2022 }} {{in lang|de}}
* [http://danubemap.eu/park/en danubemap.eu – The Tourist Map of the Danube] ([https://web.archive.org/web/20120105090451/http://danubemap.eu/park/en archive])
* [https://www.icpdr.org/ International Commission for the Protection of the Danube River]
* [http://www.bridgesofbudapest.com/ Bridges of Budapest over the Danube river]
* [http://www.thetimes.co.uk/tto/viewArticle.arc?articleId=ARCHIVE-The_Times-1877-06-14-12-001&pageId=ARCHIVE-The_Times-1877-06-14-12 Description of the Danube estuary in June 1877, ''The Times'' of London]
*[https://merhav.nli.org.il/primo-explore/search?query=any,contains,danube%20river&tab=default_tab&search_scope=Local&sortby=lso01&vid=NLI&mfacet=rtype,include,Maps,1&mfacet=tlevel,include,online_resources,1&mfacet=topic,include,Danube%20River,2&lang=en_US&came_from=sort Old maps of the Danube], Eran Laor Cartographic Collection, The National Library of Israel


[[Category:Geography of Central Europe]]

{{Sourceattribution|Danube|1}}