Editing Danube

{{Infobox river
| name = Danube
| country = {{hlist|[[Germany]]|[[Austria]]|[[Slovakia]]|[[Hungary]]|[[Croatia]]|[[Serbia]]|[[Bulgaria]]|[[Romania]]|[[Moldova]]|[[Ukraine]]}}
| source1 = [[Breg River|Breg]]
| source1_location = [[Black Forest]], [[Germany]]
| source1_elevation = 1,078 m
| source2 = [[Brigach River|Brigach]]
| source2_location = [[Black Forest]], [[Germany]]
| source2_elevation = 940 m
| source_confluence = Breg–Brigach confluence
| source_confluence_location = [[Donaueschingen]], [[Germany]]
| mouth = [[Black Sea]]
| mouth_location = [[Danube Delta]], [[Romania]]–[[Ukraine]]
| length = 2,850 km
| basin_size = 801,463 km²
| river_system = Danube river system
| cities = {{hlist|[[Vienna]]|[[Bratislava]]|[[Budapest]]|[[Belgrade]]|[[Galați]]}}
| tributaries_left = {{hlist|[[Morava River|Morava]]|[[Tisza River|Tisza]]|[[Olt River|Olt]]|[[Siret River|Siret]]|[[Prut River|Prut]]}}
| tributaries_right = {{hlist|[[Inn River|Inn]]|[[Drava River|Drava]]|[[Sava River|Sava]]|[[Great Morava]]|[[Iskar River|Iskar]]}}
}}

The '''Danube''' is a river in [[Europe]] and the continent's second-longest river after the [[Volga]]. It begins at the confluence of the Breg and Brigach rivers in the [[Black Forest]] of [[Germany]]. From there, it flows for 2,850 km across Central and Southeastern Europe before reaching the [[Black Sea]] through the [[Danube Delta]].

The main river passes through or forms part of the borders of ten countries. Its drainage basin covers 801,463 km² and extends into nineteen countries. The Danube provides a continuous inland water route between the Black Forest and the Black Sea.

== Geography ==
The upper Danube begins at [[Donaueschingen]] and flows east through southern Germany. It enters [[Austria]] near Passau, then crosses northern Austria before reaching [[Vienna]]. The river continues to [[Bratislava]], where it leaves the Alpine region and enters the Pannonian Basin.

The middle Danube flows through Hungary and passes [[Budapest]]. Farther south, it follows parts of the Croatian and Serbian borders before reaching [[Belgrade]]. It then turns east toward the Iron Gates, a gorge between the [[Carpathian Mountains|Southern Carpathians]] and the Balkan Mountains.

The lower Danube begins downstream of the Iron Gates. It forms much of the border between Bulgaria and [[Romania]], then turns north through eastern Romania before bending east toward the Black Sea. Near Tulcea, it divides into the branches of the Danube Delta.

== Hydrology ==
The Danube basin is the second-largest river basin in Europe. Mountain snowmelt and rainfall from the Alps influence the upper river, while the middle and lower sections receive water from large tributary basins. The Tisza drains the largest Danube sub-basin. The Sava contributes the greatest discharge of any Danube tributary.

Water levels vary seasonally and can rise rapidly after heavy rainfall or widespread snowmelt. Dams and embankments regulate long sections of the river, but floods remain a recurring hazard in low-lying reaches.

In the Danube Delta, the Chilia branch carries the largest share of the river's flow. The Sulina branch is maintained for navigation. The Sfântu Gheorghe branch reaches the Black Sea farther south.

== Romania ==
The Danube defines much of the southern edge of Romania. [[Wallachia]] lies between the [[Carpathian Mountains]] and the river. Its western part is [[Oltenia]], while [[Muntenia]] forms the eastern part.

The [[Argeș River]] enters the Danube near [[Oltenița]]. Farther east, [[Galați]] stands on the lower river. Its port supports freight handling and river shipping, while the city's shipyards developed beside the navigable channel.

The Iron Gates dams on the Romanian–Serbian border regulate the river and generate hydroelectric power. Downstream, the river reaches the Danube Delta, which is shared by Romania and Ukraine.

== Transport ==
The Danube has long served as an inland transport route. Commercial navigation links river ports in Central Europe with the lower Danube and the Black Sea. The [[Rhine–Main–Danube Canal]] connects the river to the Main and Rhine systems, creating a navigable route to the North Sea.

Locks and navigation channels allow vessels to pass regulated sections of the river. The [[Danube–Black Sea Canal]] provides a shorter route from the lower Danube to the coast. Navigation can still be limited by low water, ice or flooding.

International navigation is governed through agreements between the Danube states. The Danube Commission was created under the 1948 Belgrade Convention to maintain navigation conditions and coordinate technical standards. Its headquarters moved from Galați to Budapest in 1954.

== Environment ==
Floodplains and side channels support wetland habitats along the middle and lower Danube. River regulation has separated the main channel from many former floodplains. Urban wastewater enters the river system from settlements. Industrial discharges and agricultural runoff add further pressure.

The Danube Delta contains extensive reed beds. Shallow lakes are connected by natural and engineered channels. These wetlands retain sediment and filter part of the river's pollution before the water reaches the Black Sea.

== History ==
Greek and Roman writers knew the lower Danube as the Ister, while the upper river was called the Danuvius. The river later formed much of the northern frontier of the Roman Empire in southeastern Europe.

During the medieval and early modern periods, the Danube carried trade between inland settlements and the Black Sea. It also formed a political frontier between the Habsburg and Ottoman spheres in parts of Central and Southeastern Europe.

International regulation of navigation expanded during the nineteenth century. The European Commission of the Danube was established in 1856 to improve navigation near the river mouth. It operated from Galați and carried out engineering work on the Sulina branch.

== See also ==
* [[Europe]]
* [[Austria]]
* [[Romania]]
* [[Wallachia]]
* [[Muntenia]]
* [[Oltenia]]
* [[Argeș River]]
* [[Galați]]
* [[Black Sea]]
* [[Danube Delta]]

[[Category:Locations]]

[[Category:Europe]]

[[Category:Rivers of Europe]]