Danube Delta - Geography and Geology

Geography and Geology

The modern Danube Delta began forming after 4,000 BC in a gulf of the Black Sea, when the sea rose to its present level. A sandy barrier blocked the Danube gulf where the river initially built its delta. Upon filling the gulf with sediments, the delta advanced outside the barrier-blocked estuary after 3,500 BC building several successive lobes: the St. George I (3,500-1,600 BC), the Sulina (1,600-0 BC), the St. George II (0 BC-Present) and the Chilia or Kilia (1600 AD-Present). Much of the alluvium in the delta and a major expansion of its surface area in the form of lobes resulted from soil erosion associated with clearing of forests in the Danube basin during the 1st and 2nd millennium. Geologist Liviu Giosan told The New York Tmes that:

Probably 40 percent of the Delta was built in the last 1,000 years. Finding that was like a eureka moment.”

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 strandplains of the delta (Letea and Caraorman strandplains) stand higher (12.4 m and 7 m respectively). The largest lakes are Dranov (21.7 km²), Roşu (14.5 km²), Gorgova (13.8 km²).