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{{short description|River delta in Europe}}
]
{{Infobox UNESCO World Heritage Site
<table align="right" width="350">
| WHS = Danube Delta
<tr><td align="center">
| Image = File:Danube Delta ESA23450088.jpeg
]
| Location = ], Romania and ], Ukraine
</td></tr>
| ID = 588
<tr><td align="center"><small>
| Year = 1991
''Northern half of the Danube Delta <BR> Satellite photo''
| Criteria = Natural: vii, x
</small>
| Area = 312,440 ha
</td></tr>
| locmapin = Romania
</table>
| Coordinates = {{coord|45|12|N|29|30|E|display=inline,title}}
| embedded = {{Designation list
|embed = yes
|designation1 = Ramsar
|designation1_date = 21 May 1991
|designation1_number = 521<ref>{{Cite web |title=Danube Delta |website=] Sites Information Service |url=https://rsis.ramsar.org/ris/521 |access-date=25 April 2018 |archive-date=8 April 2022 |archive-url=https://web.archive.org/web/20220408154524/https://rsis.ramsar.org/ris/521 |url-status=live }}</ref>}}
}}
The '''Danube Delta''' ({{langx|ro|Delta Dunării}}, {{IPA|ro|ˈdelta ˈdunərij|pron|Ro-Delta Dunării.ogg}}; {{langx|uk|Дельта Дунаю|Del'ta Dunaju}}, {{IPA|ro|delʲˈtɑ dʊnɐˈju|pron}}) is the second largest ] in Europe, after the ], and is the best preserved on the continent.<ref name=WHS>{{Cite web |url=https://whc.unesco.org/en/list/588 |title=Danube Delta – UNESCO World Heritage Centre<!-- Bot generated title --> |access-date=2019-12-26 |archive-date=2008-01-27 |archive-url=https://web.archive.org/web/20080127014732/https://whc.unesco.org/en/list/588 |url-status=live }}</ref> Occurring where the ] empties into the ], most of the Danube Delta lies in ] (]), with a small part located in ] (]).<ref>, UNESCO. .</ref><ref>, UNESCO. .</ref> Its approximate surface area is {{convert|4,152|km2|0|abbr=off}}, of which {{cvt|3,446|km2|0}} is in Romania. With the lagoons of ] ({{cvt|1,015|km2|0|disp=or}} with {{cvt|865|km2|0|disp=or}} water surface), located south of the main delta, the total area of the Danube Delta is {{cvt|5,165|km2|0}}. The Razim–Sinoe lagoon complex is geologically and ecologically related to the delta proper; the combined territory is listed as a ].
] (2010)]]


==Geography and geology==
The '''] ]''' (3446 sq km), located in ], ] is the largest and best preserved of ] deltas.
]
The modern Danube Delta began to form after 4000 BC in a bay of the ] when the sea rose to its present level. A sandy barrier blocked the Danube bay where the river initially built its delta. Upon filling the bay with ], the delta advanced outside this barrier-blocked estuary after 3500 BC, building several successive lobes:<ref>{{cite journal |last1=Giosan |first1=Liviu |last2=Donnelly |first2=Jeffrey P. |last3=Constantinescu |first3=Stefan |last4=Filip |first4=Florin |last5=Ovejanu |first5=Ionut |last6=Vespremeanu-Stroe |first6=Alfred |last7=Vespremeanu |first7=Emil |last8=Duller |first8=Geoff A.T. |title=Young Danube delta documents stable Black Sea level since the middle Holocene: Morphodynamic, paleogeographic, and archaeological implications |journal=Geology |date=2006 |volume=34 |issue=9 |pages=757–760 |doi=10.1130/G22587.1 |bibcode=2006Geo....34..757G }}</ref> the St. George I (3500–1600 BC), the Sulina (1600–0 BC), the St. George II (0 BC–present) and the Chilia or Kilia (1600 AD–present). Several other internal lobes were constructed in the lakes and lagoons bordering the Danube Delta to the north (Chilia I and II) and toward the south (Dunavatz).<ref name=SR83012 /> Much of the ] in the delta and major expansion of its surface area in the form of lobes resulted from ] associated with human clearing of forests in the Danube basin during the ] and 2nd millennium.<ref name=NYT91412>{{cite news |title=Comments From Ancient Deforestation, a Delta Is Born |url=http://green.blogs.nytimes.com/2012/09/14/from-ancient-deforestation-a-delta-is-born/ |access-date=17 September 2012 |newspaper=The New York Times |date=14 September 2012 |author=Rachel Newer |archive-date=1 May 2021 |archive-url=https://web.archive.org/web/20210501005406/https://green.blogs.nytimes.com/2012/09/14/from-ancient-deforestation-a-delta-is-born/ |url-status=live }}</ref><ref name=SR83012>{{cite journal |title=Early Anthropogenic Transformation of the Danube-Black Sea System |journal=Scientific Reports |date=30 August 2012 |volume=2 |issue=article number 582 |pages=582 |doi=10.1038/srep00582 |author1=Liviu Giosan |author2=Marco J. L. Coolen |author3=Jed O. Kaplan |author4=Stefan Constantinescu |author5=Florin Filip |author6=Mariana Filipova-Marinova |author7=Albert J. Kettner |author8=Nick Thom |quote=Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta. |pmid=22937219 |pmc=3430877 |bibcode=2012NatSR...2..582G }}</ref> Geologist ] told ''The New York Times'':
<blockquote>Probably 40 percent of the Delta was built in the last 1000 years. Finding that was like a eureka moment.<ref name=NYT91412/></blockquote>


At present, the delta suffers from a large ], after the construction of dams on the Danube and its tributaries in the later half of the 20th century. However, construction of a dense network of shallow channels in the delta over the same period, a ], attenuated the deficit on the delta plain but increased erosion along the coast<ref>{{cite journal |last1=Giosan |first1=Liviu |last2=Constantinescu |first2=Stefan |last3=Filip |first3=Florin |last4=Deng |first4=Bing |title=Maintenance of large deltas through channelization: Nature vs. humans in the Danube delta |journal=Anthropocene |date=2013 |volume=1 |pages=35–45 |doi=10.1016/j.ancene.2013.09.001 |bibcode=2013Anthr...1...35G }}</ref><ref>{{cite web |title=Study Offers Economical Solutions for Maintaining Critical Delta Environments |url=http://www.whoi.edu/news-release/maintaining_deltas |website= |access-date=10 June 2021 }}</ref> The Danube Delta is a low ], mostly covered by ] and water. It consists of an intricate pattern of marshes, channels, streamlets and lakes. The average altitude is 0.52 m, with 20% of the territory below sea level, and more than half not exceeding one meter in altitude. Dunes on the most extensive ]s of the delta (Letea and Caraorman strand plains) stand higher (12.4 m and 7 m respectively). The largest lakes are lakes Dranov (21.7km<sup>2</sup>), Roșu (14.5km<sup>2</sup>) and Gorgova (13.8km<sup>2</sup>).
==Geography==
]


=== Distributaries of the Danube ===
Every year, the alluviam brought in by the Danube increases the width of the Delta with around 40 meters, making it extremely dynamic. Near ], the Danube is divided in three river branches before it flows into the Sea: ], ] and ] (''Saint George''), but many other channels make split the Delta into areas with ], ]es and ]s, some of which are flooded during the spring and autumn.


The ] branches into three main ] into the ], ''']''', ''']''', and '''] (Saint George)'''. The last two branches form the '''Tulcea''' channel, which continues as a single body for several kilometers after the separation from the Chilia. At the mouths of each channel ] takes place, as the delta continues to expand.
About 44 km of the Danube Delta lies the ], a territory claimed by both ] and ].


{| class="wikitable"
<table align="right" width="350">
|+ Main distributaries of the Danube
<tr><td align="center">
|-
]
! Danube arm
</td></tr>
!Length (km)
<tr><td align="center"><small>
!Flow (m<sup>3</sup>/s)<br>(1921–1990)
''Image from the Danube Delta''
|-
</small>
| ''' ]'''
</td></tr>
| 120
</table>
| 3800
|-
| ''' ]'''
| 64
| 1250
|-
| ''' ]'''
''' (Saint George)'''
| 70
| 1500
|-
|}
]
''']''', in the north, the longest, youngest, and most vigorous, with two secondary internal deltas and one microdelta in full process of formation at its mouth (to Ukraine).


''']''', the central and thus the shortest arm, which consequently led to its extensive use for traffic and severe transformation. At its mouth is located the main port and a single settlement with urban characteristics of the Romanian part of the delta. Because of the ] deposited at its mouth, a channel gradually advancing into the sea (presently it has 10km) was built in order to protect navigation.
==Nature==


] ('''Saint George''' in English), in the south, is the oldest and most sparsely populated. Its ] has led to the creation, beginning in 1897, of the ]s, which today measures 19km in length.
It hosts over 1,200 varieties of plants, 300 species of birds as well as 45 freshwater fish species in its numerous lakes and marshes. The Danube Delta has been entered onto the ] list of ] and a reservation of the biosphere. Around 2,733 km&sup2 of it are strictly protected areas.
]
]


=== Climate ===
This is the place where millions of birds from different places of Earth (European, Asian, African, Mediteraneean) come to lay their eggs.


The Danube Delta is considred to be among Romania's sunniest and driest regions.<ref>{{Cite web |last=Pont |first=Ulrich |date=2021 |title=Thermal Performance Analysis of Vernacular Houses in the Danube Delta |url=https://repositum.tuwien.at/bitstream/20.500.12708/18532/1/Ivan%20Adrian%20Bebe%20-%202021%20-%20Thermal%20performance%20analysis%20of%20vernacular%20houses%20in...pdf |access-date=24 November 2024 |website=Teschnische Universität Wien}}</ref> The mean annual temperature is 11°C (−1°C in January and 22&nbsp;°C in July), with mean precipitation between 400mm/year and 300mm/year.
Around 2,500 years ago, as ] says that the Danube was divided in seven branches.

=== {{anchor|Main ecosytems}}Main ecosystems ===
]
]]]

The Danube Delta falls within the ] ] of eastern Europe, with Mediterranean influences. As a young region in full process of consolidation, the Danube Delta represents a very favourable place for the development of highly diverse ] and ], unique{{clarify|date=January 2016}} in Europe, with numerous rare species. It hosts 23 natural ecosystems, but due to the extent of ] an aquatic environment is prevalent; a terrestrial environment is also present on the higher grounds of the continental ], where ] ecosystems have developed. Between the aquatic and terrestrial environments is interposed a swampy, easily flooded strip of original flora and fauna, with means of adaptation to water or land, depending on the season or ] regime. At the contact between freshwater and sea water, some special physical, chemical and biological processes take place, which have led biologists to consider this area as a very different ecosystem called '''beforedelta'''. Musura Gulf, north of Sulina, and Saint George Gulf are considered the most representative of this type of ecosystem.

Situated on major migratory routes, and providing adequate conditions for nesting and hatching, the Danube Delta is a magnet for birds from six major ] of the world, including the Mongolian, Arctic and Siberian. There are over 320 species of birds found in the delta during summer,<ref>{{Cite web |url=https://whc.unesco.org/en/list/588/video |title=Danube Delta – UNESCO World Heritage Centre<!-- Bot generated title --> |access-date=2019-12-26 |archive-date=2019-05-10 |archive-url=https://web.archive.org/web/20190510210914/http://whc.unesco.org/en/list/588/video |url-status=live }}</ref> of which 166 are hatching species and 159 are migratory. Over one million individual birds (including swans, ducks, and ]) winter here.

==== Ecosystem of running water ====

This comprises the arms of the Danube, and a series of its more important streamlets and channels. It is an environment rich in ], worms, ]s, ]s, and ]s, with numerous species of fish, such as the ], ], ], ], and freshwater ] (], Vyza{{Typo help inline|reason=Vyza? Please give Latin name|date=February 2021}} and Danube mackerel{{Typo help inline|reason=Suspicious vernacular name. Please give Latin name|date=February 2021}}).

==== Ecosystem of stagnant water ====
]'' in the Danube Delta]]
This environment includes the lakes, and various ponds, streamlets and channels. It is characterized by a rich floating and submerse flora ('']'', '']'', '']'', under the water; '']'', '']'', '']'', '']'', floating plants with roots near the lakes' borders; and '']'', '']'', '']'', floating plants without roots, having negative effect for aquatic ]). Of the fish, the most important are ] (''Tinca tinca''), ] (''Abramis brama''), ] (''Scardinius erythropthalmus''), ] (''Carassius auratus gibelio''), ] (''Silurus glanis''), ] (''Perca fluviatilis''), and ] (''Esox lucius'').

==== Ecosystem of marshy and flooding areas ====
]
] (''Ardea cinerea''), ] or wild duck (''Anas platyrhynchos''), ] (''Ardea cinerea''), ] (''Podiceps cristatus''). Stamp of Romania, 2004]]

Reed plants and floating reed islands (called '''plaur''' in ]) are the most common and well-known components of the Danube Delta. Vegetation of this ecosystem consists of the common reed ('']'') and, on near river banks, mace reed/cattail ('']'', '']''), sedge ('']'', '']''), Dutch rush ('']'', '']''), and brook mint ('']''). They provide ideal spawning and nesting grounds. The '''plaur''' are a mixture of reed roots, grass and soil, usually floating or anchored to the riverbed. As a rule, the reed surrounds the lakes and ponds, and slowly invades the water surface.

This type of ecosystem is noted for its variety and large population of birds, some of them are very rare. The most important are the ] (''Aythya fuligula''), ] (''Netta rufina''), ] (''Anas platyrhynchos''), ] (''Anser anser''), ] (''Microcarbo pygmeus''), ] (''Ardea purpurea''), ] (''Egretta alba''), ] (''Egretta garzetta''), ](''Platalea leucorodia''), ] (''Pelecanus onocrotalus''), ] (''Pelecanus crispus''), ] (''Cygnus olor''), and ] (''Plegadis falcinellus''). A recent and welcomed newcomer is the ] (''Phasianus colchicus'').

Among the mammals, there is the ] (''Lutra lutra''), ] (''Mustela lutreola''), ] (''Mustela erminea aestiva''), ] (''Sus scrofa''), and ] (''Felis silvestris''), in winter the ] (''Lepus europaeus'') and, on the brink of disappearing from the delta, the wolf and the fox. During the Middle Ages, the ] (''Panthera tigris tigris'') was a resident across the steppes of Ukraine, including Danube Delta, and once, they were hunted to extinction and they're extirpated. The ] (''Nyctereutes procyonoides''), bizam/introduced ] (''Ondatra zibethica''), and to some extent South American ] (''Myocastor coypus''), are recent species that have successfully adapted.

==== River bank and levee ecosystems ====
]

The firm land of the delta used to be covered with large groves of willow trees, which have been cut down almost entirely and replaced with Canadian poplars. On the river banks kept in their natural state, small groves of willow trees ('']'', '']'', '']'', '']'', and '']'') can still be found, mixed with white poplar ('']''). Occasionally, the willow trees form corridors along the arms and bigger channels of the Danube. On the ] of ] and ], mixed forests of oaks ('']'', and '']'') with various other trees ('']'', '']'', '']''), shrubs ('']'', '']'', '']'', and '']'', among others), and vines ('']'', '']'', '']'', '']'', which reaches up to 25m) grow on ] areas. On the Letea levee, these exotic-looking forests grow especially in the depressions between the sand dunes, in small groves called '''hasmace'''. Fauna of this region include the ] (''Vipera ursinii''), ] (''Pandion haliaetus''), and ] (''Bubo bubo'').


==Inhabitants== ==Inhabitants==
{{more citations needed|date=August 2024}}
]
] (Ukraine)]]


With an average population density of 2 people per km<sup>2</sup>, the Danube Delta is one of the least inhabited regions of temperate Europe.<ref name="The Danube Delta-Halmyris">{{Cite web |url=http://www.halmyris.org/history/danube-delta |title=The Danube Delta – Halmyris |website=www.halmyris.org |language=en-US |access-date=18 December 2017 |archive-date=9 July 2018 |archive-url=https://web.archive.org/web/20180709155001/http://www.halmyris.org/history/danube-delta |url-status=dead }}</ref> On the Romanian side live about 20,000 people, of whom 4,600 live in the port of ].{{citation needed|date=April 2021}}. The rest of the population is scattered among 27 villages, of which only three, all situated marginally, had more than 500 people in 2002.{{citation needed|date=August 2024}} The city of ], at the western edge of the delta, has a population of 92,000 (in 2002); it represents the node of the region and the gate to the delta.<ref name="The Danube Delta-Halmyris"/>
Around 15,000 people live in the Delta, most of them are living off fishing with their traditional wooden ]s. It includes a community of ]s which are descendants of the Old Rite Followers who left ] in ] to avoid religious persecutions.

Its acute isolation and harsh conditions of living, based mainly on subsistence, made the Danube Delta a place of emigration, or transit at least. Very few of those born in the region stay there through adulthood; at the same time, the origins of its inhabitants vary widely, as people from many parts of ] can be found in the delta. The total population has remained more or less constant throughout the 20th century; there were 12,000 inhabitants in the 1890s, and 14,000 before the Second World War.{{citation needed|date=August 2024}} ] account for approximately 80% of the population, and ] for 10%. Other people living in the delta include ethnic minorities such as Greeks, Turks and Bulgarians (in 1992). Distinctive to the region, but very rare as an ethnic entity, are the ], descendants of the Orthodox Old Rite followers who fled from religious persecution in Russia during the 18th century.

On the Ukrainian side, located at the northern edge of the delta, the town of ] has a population of 85,000, ] a population of 21,800, and ], the main center of the ] community, a population of 9,300.

==History==
]

Recorded history notes that the ] lived in the Danube Delta before it was conquered by the ]. After later invasion by the ], the region changed hands many times. During the 15th century, the Danube Delta became part of the ]. In 1812, following the ], the borders of the Ottoman and ]s were set by the Kilia and Old Stambul Channels of the Danube, and in 1829 by the St George Channel. The ], which ended the ], assigned the Danube Delta to the ] and ] which undertook a series of works to help navigation. In 1878, following the ] by Russia and Romania, the border between the two countries was set by the Kilia and Old Stambul Channels.

In 1991, the Romanian part of the Danube Delta became part of ]'s list of ]s. Around 2,733km<sup>2</sup> of the delta are strictly protected areas.

In 1998, under UNESCO's ], the 6,264.03km<sup>2</sup> of the Danube Delta were established as a ], shared by Romania and Ukraine.

Historically, in Romania, part of the Danube Delta was marked as a reserve in 1938.

In Ukraine, the Danube branch of the Black Sea State Reserve was established in 1973. In 1981, it was reorganized into the Natural Reserve "Danube Fluxes", and in 1998, it was extended into the Danube biosphere reserve.

== Environmental issues ==
{{citations needed|section|date=August 2018}}

Large-scale works began in the Danube Delta as early as the second half of the 19th century.<ref>Iordachi, Constantin, Van Assche, Kristof (2014) The Bio-Politics of the Danube Delta. {{Webarchive|url=https://web.archive.org/web/20150410184124/https://rowman.com/ISBN/9780739195154 |date=2015-04-10 }}. {{ISBN|978-0-7391-9514-7 }}</ref> First corrections of the Sulina arm began in 1862, and they continued throughout the 20th century. As a result, the length of the Sulina arm was reduced from 92 to 64&nbsp;km, and its flow more than doubled, thus making it suitable for large-vessel navigation. Correcting the six large ] on its course thereby reduced the length of the Sfântu Gheorghe branch from 108 to 70km, and its flow also increased somewhat. Both these increases were made to the detriment of the Chilia arm, which at present remains the most unspoiled arm of the main three. These corrections, as well as the digging of various secondary channels throughout the body of the delta, have had a serious impact on the ecosystem. Natural environments have been altered, the breeding pattern of fish has been disrupted, and the flows in the main arms have increased, with serious consequences regarding the discharge of ] and the erosion of banks.

Reed was intensively harvested during the ] era. The regime had plans to transform the delta into a large agro-industrial zone. Although the first modern agricultural exploitation dates from 1939 (Ostrovul Tãtaru), only after 1960 were large areas drained and converted, to the detriment of the wetlands. In 1991, agricultural land in the delta surpassed 100,000 hectares, and more than a third of its surface has been affected by crop cultivation, ], or ] (fish farming). As a result of these changes, along with the increasing pollution and ] of the waters of the Danube, and decades of exploitation and poor fishing regulations, the fish population has been visibly reduced.

In 2004, Ukraine inaugurated work on the ] that would provide an additional navigable link from the Black Sea to the populous Ukrainian section of the Danube Delta. However, because of the negative impact which this new channel might have on the fragile ecosystem of the delta, the ] advised Ukraine to shut down the works. Romanian officials threatened to sue Ukraine at the ]. Under the presidency of ], Ukraine had responded that Romania was only afraid of the competition that the new channel would bring, and continued working on the channel. Under the presidency of ], who visited Romania in 2005, both sides agree that professionals should decide the fate of the channel. In the long run, Ukraine plans to build a navigation channel, if not through Bistroe Channel, then through another channel.

==Gallery==
{{gallery|mode=packed
|Sulina 4.jpg|] – 1870 lighthouse
|DeltaRBDD.jpg|The natural reservations of the Danube delta (red: in Ukraine; yellow/red: in Romania)
|DeltaPierderi.jpg|Territorial losses of Romania in the Danube delta since 1948
|Areas polderised under Ceausescu.png|Dyked and dried areas in the ]
|Danube Delta Reeds.JPG|] growing in the Danube Delta
}}

==See also==
{{Geography of Romania}}
* ]
* ]
* ]
* ]
* ]
* ]
* ]

<small>'''A series of articles on control of the Danube, in chronological order'''</small>
* ], for events from earliest times to the Treaty of Paris in 1856
* ], for the international body governing the waterway from 1856 to 1940
* ], for events during World War II
* ]
* ], for the organization established in 1998 and charged with environmental and ecological activities

==References==
{{Reflist}}


==External links== ==External links==
{{Commons category|Danube Delta}}
*
* {{Webarchive |url=https://web.archive.org/web/20170920101547/http://danube-delta.org/ |date=20 September 2017 }} - Danube Delta map, travel, photos, videos and reviews in Danube Delta Romania
*
* *
<!--

*
*
* {{en icon}}
* - navigate along the channels in Google Street View panoramic fashion
* -->

{{Seven Natural Wonders of Romania}}
{{World Heritage Sites in Romania}}
{{Protected areas of Romania}}
{{Protected areas of Ukraine}}

{{Authority control}}

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Latest revision as of 00:03, 24 November 2024

River delta in Europe
Danube Delta
UNESCO World Heritage Site
LocationTulcea County, Romania and Odesa Oblast, Ukraine
CriteriaNatural: vii, x
Reference588
Inscription1991 (15th Session)
Area312,440 ha
Coordinates45°12′N 29°30′E / 45.200°N 29.500°E / 45.200; 29.500
Ramsar Wetland
Designated21 May 1991
Reference no.521
Danube Delta is located in RomaniaDanube DeltaLocation of Danube Delta in Romania

The Danube Delta (Romanian: Delta Dunării, pronounced [ˈdelta ˈdunərij] ; Ukrainian: Дельта Дунаю, romanizedDel'ta Dunaju, pronounced [delʲˈtɑ dʊnɐˈju]) is the second largest river delta in Europe, after the Volga Delta, and is the best preserved on the continent. Occurring where the Danube River empties into the Black Sea, most of the Danube Delta lies in Romania (Tulcea County), with a small part located in Ukraine (Odesa Oblast). Its approximate surface area is 4,152 square kilometres (1,603 square miles), of which 3,446 km (1,331 sq mi) is in Romania. With the lagoons of Razim–Sinoe (1,015 km or 392 sq mi with 865 km or 334 sq mi water surface), located south of the main delta, the total area of the Danube Delta is 5,165 km (1,994 sq mi). The Razim–Sinoe lagoon complex is geologically and ecologically related to the delta proper; the combined territory is listed as a World Heritage Site.

Danube Delta near Tulcea (2010)

Geography and geology

Historical evolution of the Danube Delta (AD 1 – 2015)

The modern Danube Delta began to form after 4000 BC in a bay of the Black Sea when the sea rose to its present level. A sandy barrier blocked the Danube bay where the river initially built its delta. Upon filling the bay with sediment, the delta advanced outside this barrier-blocked estuary after 3500 BC, building several successive lobes: the St. George I (3500–1600 BC), the Sulina (1600–0 BC), the St. George II (0 BC–present) and the Chilia or Kilia (1600 AD–present). Several other internal lobes were constructed in the lakes and lagoons bordering the Danube Delta to the north (Chilia I and II) and toward the south (Dunavatz). Much of the alluvium in the delta and major expansion of its surface area in the form of lobes resulted from soil erosion associated with human clearing of forests in the Danube basin during the 1st and 2nd millennium. Geologist Liviu Giosan told The New York Times:

Probably 40 percent of the Delta was built in the last 1000 years. Finding that was like a eureka moment.

At present, the delta suffers from a large sediment deficit, after the construction of dams on the Danube and its tributaries in the later half of the 20th century. However, construction of a dense network of shallow channels in the delta over the same period, a sedimentation enhancing strategy, attenuated the deficit on the delta plain but increased erosion along the coast The Danube Delta is a low alluvial plain, mostly covered by wetlands and water. It consists of an intricate pattern of marshes, channels, streamlets and lakes. The average altitude is 0.52 m, with 20% of the territory below sea level, and more than half not exceeding one meter in altitude. Dunes on the most extensive strand plains of the delta (Letea and Caraorman strand plains) stand higher (12.4 m and 7 m respectively). The largest lakes are lakes Dranov (21.7km), Roșu (14.5km) and Gorgova (13.8km).

Dalmatian pelican and great cormorant

Distributaries of the Danube

The Danube branches into three main distributaries into the delta, Chilia, Sulina, and Sfântul Gheorghe (Saint George). The last two branches form the Tulcea channel, which continues as a single body for several kilometers after the separation from the Chilia. At the mouths of each channel gradual formation of new land takes place, as the delta continues to expand.

Main distributaries of the Danube
Danube arm Length (km) Flow (m/s)
(1921–1990)
Chilia 120 3800
Sulina 64 1250
Sfântu Gheorghe

(Saint George)

70 1500
Danube Delta Distributary in Kyslytsia village, Ukraine

Chilia, in the north, the longest, youngest, and most vigorous, with two secondary internal deltas and one microdelta in full process of formation at its mouth (to Ukraine).

Sulina, the central and thus the shortest arm, which consequently led to its extensive use for traffic and severe transformation. At its mouth is located the main port and a single settlement with urban characteristics of the Romanian part of the delta. Because of the alluvium deposited at its mouth, a channel gradually advancing into the sea (presently it has 10km) was built in order to protect navigation.

Sfântul Gheorghe (Saint George in English), in the south, is the oldest and most sparsely populated. Its alluvium has led to the creation, beginning in 1897, of the Sacalin Islands, which today measures 19km in length.

Map created in 2010
Danube Delta in Romania

Climate

The Danube Delta is considred to be among Romania's sunniest and driest regions. The mean annual temperature is 11°C (−1°C in January and 22 °C in July), with mean precipitation between 400mm/year and 300mm/year.

Main ecosystems

Danube Delta in Romania
Danube Delta: old mill in Letea

The Danube Delta falls within the Pannonian steppe ecosystem of eastern Europe, with Mediterranean influences. As a young region in full process of consolidation, the Danube Delta represents a very favourable place for the development of highly diverse flora and fauna, unique in Europe, with numerous rare species. It hosts 23 natural ecosystems, but due to the extent of wetlands an aquatic environment is prevalent; a terrestrial environment is also present on the higher grounds of the continental levees, where xerophile ecosystems have developed. Between the aquatic and terrestrial environments is interposed a swampy, easily flooded strip of original flora and fauna, with means of adaptation to water or land, depending on the season or hydrological regime. At the contact between freshwater and sea water, some special physical, chemical and biological processes take place, which have led biologists to consider this area as a very different ecosystem called beforedelta. Musura Gulf, north of Sulina, and Saint George Gulf are considered the most representative of this type of ecosystem.

Situated on major migratory routes, and providing adequate conditions for nesting and hatching, the Danube Delta is a magnet for birds from six major ecoregions of the world, including the Mongolian, Arctic and Siberian. There are over 320 species of birds found in the delta during summer, of which 166 are hatching species and 159 are migratory. Over one million individual birds (including swans, ducks, and coots) winter here.

Ecosystem of running water

This comprises the arms of the Danube, and a series of its more important streamlets and channels. It is an environment rich in plankton, worms, molluscs, grubs, and sponges, with numerous species of fish, such as the carp, pike, pike perch, sheat-fish, and freshwater sturgeons (sterlet, Vyza and Danube mackerel).

Ecosystem of stagnant water

Nymphaea alba in the Danube Delta

This environment includes the lakes, and various ponds, streamlets and channels. It is characterized by a rich floating and submerse flora (Myriophyllum, Ceratophyllum, Vallisneria, under the water; Nymphaea alba, Nuphar lutea, Trapa natans, Alisma plantago, floating plants with roots near the lakes' borders; and Salvinia natans, Stratiotes aloides, Spirogyra, floating plants without roots, having negative effect for aquatic bioproductivity). Of the fish, the most important are Tench (Tinca tinca), common bream (Abramis brama), common rudd (Scardinius erythropthalmus), Prussian carp (Carassius auratus gibelio), wels catfish (Silurus glanis), European perch (Perca fluviatilis), and northern pike (Esox lucius).

Ecosystem of marshy and flooding areas

Pelicans in Danube Delta
The Danube Delta birds: grey heron (Ardea cinerea), mallard or wild duck (Anas platyrhynchos), great white pelican (Ardea cinerea), great crested grebe (Podiceps cristatus). Stamp of Romania, 2004

Reed plants and floating reed islands (called plaur in Romania) are the most common and well-known components of the Danube Delta. Vegetation of this ecosystem consists of the common reed (Phragmites communis) and, on near river banks, mace reed/cattail (Typha latifolia, Typha angustifolia), sedge (Carex dioica, Carex stricta), Dutch rush (Scirpus radicans, Schoenoplectus lacustris), and brook mint (Mentha aquatica). They provide ideal spawning and nesting grounds. The plaur are a mixture of reed roots, grass and soil, usually floating or anchored to the riverbed. As a rule, the reed surrounds the lakes and ponds, and slowly invades the water surface.

This type of ecosystem is noted for its variety and large population of birds, some of them are very rare. The most important are the tufted duck (Aythya fuligula), red-crested pochard (Netta rufina), mallard (Anas platyrhynchos), greylag goose (Anser anser), pygmy cormorant (Microcarbo pygmeus), purple heron (Ardea purpurea), great white egret (Egretta alba), little egret (Egretta garzetta), Eurasian spoonbill(Platalea leucorodia), great white pelican (Pelecanus onocrotalus), Dalmatian pelican (Pelecanus crispus), mute swan (Cygnus olor), and glossy ibis (Plegadis falcinellus). A recent and welcomed newcomer is the pheasant (Phasianus colchicus).

Among the mammals, there is the Eurasian otter (Lutra lutra), European mink (Mustela lutreola), little ermine (Mustela erminea aestiva), wild boar (Sus scrofa), and wild cat (Felis silvestris), in winter the European hare (Lepus europaeus) and, on the brink of disappearing from the delta, the wolf and the fox. During the Middle Ages, the Caspian tiger (Panthera tigris tigris) was a resident across the steppes of Ukraine, including Danube Delta, and once, they were hunted to extinction and they're extirpated. The East Asian raccoon dog (Nyctereutes procyonoides), bizam/introduced muskrat (Ondatra zibethica), and to some extent South American nutria (Myocastor coypus), are recent species that have successfully adapted.

River bank and levee ecosystems

Black-crowned night heron

The firm land of the delta used to be covered with large groves of willow trees, which have been cut down almost entirely and replaced with Canadian poplars. On the river banks kept in their natural state, small groves of willow trees (Salix alba, Salix fragilis, Salix purpurea, Salix pentandra, and Salix triandra) can still be found, mixed with white poplar (Populus alba). Occasionally, the willow trees form corridors along the arms and bigger channels of the Danube. On the levees of Letea and Caraorman, mixed forests of oaks (Quercus robur, and Quercus pedunculiflora) with various other trees (Fraxinus pallisiae, Ulmus foliaceae, Populus tremula), shrubs (Prunus spinosa, Crataegus monogyna, Rosa canina, and Berberis vulgaris, among others), and vines (Vitis sylvestris, Hedera helix, Humulus lupulus, Periploca graeca, which reaches up to 25m) grow on sand dune areas. On the Letea levee, these exotic-looking forests grow especially in the depressions between the sand dunes, in small groves called hasmace. Fauna of this region include the meadow viper (Vipera ursinii), osprey (Pandion haliaetus), and Eurasian eagle owl (Bubo bubo).

Inhabitants

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Lipovan fisherman of Chilia Veche
Vylkove (Ukraine)

With an average population density of 2 people per km, the Danube Delta is one of the least inhabited regions of temperate Europe. On the Romanian side live about 20,000 people, of whom 4,600 live in the port of Sulina.. The rest of the population is scattered among 27 villages, of which only three, all situated marginally, had more than 500 people in 2002. The city of Tulcea, at the western edge of the delta, has a population of 92,000 (in 2002); it represents the node of the region and the gate to the delta.

Its acute isolation and harsh conditions of living, based mainly on subsistence, made the Danube Delta a place of emigration, or transit at least. Very few of those born in the region stay there through adulthood; at the same time, the origins of its inhabitants vary widely, as people from many parts of Romania can be found in the delta. The total population has remained more or less constant throughout the 20th century; there were 12,000 inhabitants in the 1890s, and 14,000 before the Second World War. Romanians account for approximately 80% of the population, and Ukrainians for 10%. Other people living in the delta include ethnic minorities such as Greeks, Turks and Bulgarians (in 1992). Distinctive to the region, but very rare as an ethnic entity, are the Lipovans, descendants of the Orthodox Old Rite followers who fled from religious persecution in Russia during the 18th century.

On the Ukrainian side, located at the northern edge of the delta, the town of Izmail has a population of 85,000, Kiliya a population of 21,800, and Vilkovo, the main center of the Lipovan community, a population of 9,300.

History

The Danube Delta in 1867, as a part of the Ottoman Empire

Recorded history notes that the Dacians lived in the Danube Delta before it was conquered by the Romans. After later invasion by the Goths, the region changed hands many times. During the 15th century, the Danube Delta became part of the Ottoman Empire. In 1812, following the Russo-Turkish War, the borders of the Ottoman and Russian Empires were set by the Kilia and Old Stambul Channels of the Danube, and in 1829 by the St George Channel. The Treaty of Paris of 1856, which ended the Crimean War, assigned the Danube Delta to the Ottoman Empire and established an international commission which undertook a series of works to help navigation. In 1878, following the defeat of Ottoman Empire by Russia and Romania, the border between the two countries was set by the Kilia and Old Stambul Channels.

In 1991, the Romanian part of the Danube Delta became part of UNESCO's list of World Heritage Sites. Around 2,733km of the delta are strictly protected areas.

In 1998, under UNESCO's Programme on Man and the Biosphere, the 6,264.03km of the Danube Delta were established as a biosphere reserve, shared by Romania and Ukraine.

Historically, in Romania, part of the Danube Delta was marked as a reserve in 1938.

In Ukraine, the Danube branch of the Black Sea State Reserve was established in 1973. In 1981, it was reorganized into the Natural Reserve "Danube Fluxes", and in 1998, it was extended into the Danube biosphere reserve.

Environmental issues

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Large-scale works began in the Danube Delta as early as the second half of the 19th century. First corrections of the Sulina arm began in 1862, and they continued throughout the 20th century. As a result, the length of the Sulina arm was reduced from 92 to 64 km, and its flow more than doubled, thus making it suitable for large-vessel navigation. Correcting the six large meanders on its course thereby reduced the length of the Sfântu Gheorghe branch from 108 to 70km, and its flow also increased somewhat. Both these increases were made to the detriment of the Chilia arm, which at present remains the most unspoiled arm of the main three. These corrections, as well as the digging of various secondary channels throughout the body of the delta, have had a serious impact on the ecosystem. Natural environments have been altered, the breeding pattern of fish has been disrupted, and the flows in the main arms have increased, with serious consequences regarding the discharge of alluvia and the erosion of banks.

Reed was intensively harvested during the Communist era. The regime had plans to transform the delta into a large agro-industrial zone. Although the first modern agricultural exploitation dates from 1939 (Ostrovul Tãtaru), only after 1960 were large areas drained and converted, to the detriment of the wetlands. In 1991, agricultural land in the delta surpassed 100,000 hectares, and more than a third of its surface has been affected by crop cultivation, forest plantation, or pisciculture (fish farming). As a result of these changes, along with the increasing pollution and eutrophication of the waters of the Danube, and decades of exploitation and poor fishing regulations, the fish population has been visibly reduced.

In 2004, Ukraine inaugurated work on the Bistroe Channel that would provide an additional navigable link from the Black Sea to the populous Ukrainian section of the Danube Delta. However, because of the negative impact which this new channel might have on the fragile ecosystem of the delta, the European Union advised Ukraine to shut down the works. Romanian officials threatened to sue Ukraine at the International Court of Justice. Under the presidency of Kuchma, Ukraine had responded that Romania was only afraid of the competition that the new channel would bring, and continued working on the channel. Under the presidency of Yuschenko, who visited Romania in 2005, both sides agree that professionals should decide the fate of the channel. In the long run, Ukraine plans to build a navigation channel, if not through Bistroe Channel, then through another channel.

Gallery

  • Sulina – 1870 lighthouse Sulina – 1870 lighthouse
  • The natural reservations of the Danube delta (red: in Ukraine; yellow/red: in Romania) The natural reservations of the Danube delta (red: in Ukraine; yellow/red: in Romania)
  • Territorial losses of Romania in the Danube delta since 1948 Territorial losses of Romania in the Danube delta since 1948
  • Dyked and dried areas in the communist time Dyked and dried areas in the communist time
  • Reeds growing in the Danube Delta Reeds growing in the Danube Delta

See also

Geography of Romania
Topography

Carpathians (peaks)
Plains & Delta
Islands

Hydrography

Rivers (Danube)
Lakes
Black Sea

Climate

A series of articles on control of the Danube, in chronological order

References

  1. "Danube Delta". Ramsar Sites Information Service. Archived from the original on 8 April 2022. Retrieved 25 April 2018.
  2. "Danube Delta – UNESCO World Heritage Centre". Archived from the original on 2008-01-27. Retrieved 2019-12-26.
  3. Biosphere Reserves in Ukraine, UNESCO. .
  4. Biosphere Reserves: Danube Delta, UNESCO. .
  5. Giosan, Liviu; Donnelly, Jeffrey P.; Constantinescu, Stefan; Filip, Florin; Ovejanu, Ionut; Vespremeanu-Stroe, Alfred; Vespremeanu, Emil; Duller, Geoff A.T. (2006). "Young Danube delta documents stable Black Sea level since the middle Holocene: Morphodynamic, paleogeographic, and archaeological implications". Geology. 34 (9): 757–760. Bibcode:2006Geo....34..757G. doi:10.1130/G22587.1.
  6. ^ Liviu Giosan; Marco J. L. Coolen; Jed O. Kaplan; Stefan Constantinescu; Florin Filip; Mariana Filipova-Marinova; Albert J. Kettner; Nick Thom (30 August 2012). "Early Anthropogenic Transformation of the Danube-Black Sea System". Scientific Reports. 2 (article number 582): 582. Bibcode:2012NatSR...2..582G. doi:10.1038/srep00582. PMC 3430877. PMID 22937219. Sediment loads delivered by Danube River, the main tributary of the Black Sea, significantly increased as land use intensified in the last two millennia, which led to a rapid expansion of its delta.
  7. ^ Rachel Newer (14 September 2012). "Comments From Ancient Deforestation, a Delta Is Born". The New York Times. Archived from the original on 1 May 2021. Retrieved 17 September 2012.
  8. Giosan, Liviu; Constantinescu, Stefan; Filip, Florin; Deng, Bing (2013). "Maintenance of large deltas through channelization: Nature vs. humans in the Danube delta". Anthropocene. 1: 35–45. Bibcode:2013Anthr...1...35G. doi:10.1016/j.ancene.2013.09.001.
  9. "Study Offers Economical Solutions for Maintaining Critical Delta Environments". Retrieved 10 June 2021.
  10. Pont, Ulrich (2021). "Thermal Performance Analysis of Vernacular Houses in the Danube Delta" (PDF). Teschnische Universität Wien. Retrieved 24 November 2024.
  11. "Danube Delta – UNESCO World Heritage Centre". Archived from the original on 2019-05-10. Retrieved 2019-12-26.
  12. ^ "The Danube Delta – Halmyris". www.halmyris.org. Archived from the original on 9 July 2018. Retrieved 18 December 2017.
  13. Iordachi, Constantin, Van Assche, Kristof (2014) The Bio-Politics of the Danube Delta. Lexington Books Archived 2015-04-10 at the Wayback Machine. ISBN 978-0-7391-9514-7

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