The Genesis and Evolution of Danube Delta

Referring to Danube Delta's genesis and evolution, information that we have got from the antique historians, corroborated with the most recent data, let us reconstitute, in space and time, the Delta's territory. Almost all theories converge to the idea of genesis through bay-lagoon-delta phases.

According to these theories, the genesis of delta took place in an old sea bay, isolated by a narrow sand bank, which transformed its western side in a lagoon. Before ending the process of sand filling, the dominant winds from NE associated with high waves accumulated the sand hillocks of Letea and Caraorman. Using the advanced parts of these hillocks, the sea builds new series of sea sides which are closing behind lagoon sectors, themselves filled by the river with sand after. This is the mechanism through which the Danube delta advances continuously into the sea.

Between the factors which contribute to delta's evolution, the most important is the Danube river which, with its solid transport, forces the delta to advance continuously into the sea. (the medium speed of advancing during 1835-1992 was 17.405 m/an). It pours its waters into the sea through three channels: Chilia- 84 km, Sulina-77 km and Sfantul Gheorghe (Sahalin Island)-81 km.

This generative process has been, during the last decades, considerably deteriorated because of the many dams built on inner Romanian tributaries of Danube, of the Portile de Fier's dam and of the dams built in Germany and Austria having as the first effect the diminishing of the quantity of sand that Danube carries with its waters. It is a factor of concern for Delta's evolution.