Mahmudia is a commune in Tulcea County, Romania. It is
composed of a single village, Mahmudia. It included the villages of Beştepe,
Băltenii de Jos and Băltenii de Sus until 2004, when these were split off to
form Beştepe Commune.
The Danube Delta (Romanian: Delta Dunării pronounced [ˈdelta
ˈdunərij] ( listen); Ukrainian: Дельта Дунаю, Deľta Dunayu, Ukrainian
pronunciation: [deʎˈtɐ dunɑˈju]) is the second largest river delta in Europe,
after the Volga Delta, and is the best preserved on the continent. 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 (Odessa
Oblast). Its approximate surface area is 4,152 km2 (1,603 sq mi), of which
3,446 km2 (1,331 sq mi) is in Romania. With the lagoons of Razim–Sinoe (1,015
km2 (392 sq mi) with 865 km2 (334 sq mi) water surface), located south of the
main delta, the total area of the Danube Delta is 5,165 km2 (1,994 sq mi). The
Razim–Sinoe lagoon complex is geologically and ecologically related to the
delta proper and the combined territory is listed as a World Heritage Site.
The modern Danube Delta began to form after 4000 BCE 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 BCE, building several successive lobes: the St. George I (3500–1600
BCE), the Sulina (1600–0 BCE), the St. George II (0 BC–present) and the Chilia
or Kilia (1600 CE–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 the clearing of forests in the Danube basin during the 1st and
2nd millennium.
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 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 (21.7 km2), Roșu (14.5 km2)
and Gorgova (13.8 km2).
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