The Danube Delta represents the youngest geographical region of Romania
, with a particular individuality between the European deltas, as well
as between the worldwide deltas.
Situated in the northwestern part of Black Sea basin,
between 44º46'00'' N lat., 45º40'00'' lat. N. and 28º40'24'' long.
E., 29º40'50'' long. E., in a mobile region of the earth crust,
the Danube Delta represents practically the most important terminal
plain of an European river. (excepting the one of Volga river). The
total area of the delta is 4178 km 2 , 3486 km 2 being on the Romanian
territory (82 %) and, respectively, 732 km 2 is on Ukrainean territory
(18 %). The Delta's limits can be extended to Capul Midia, including
the lagoonary complex Razim-Sinoe.
It is a classical delta, well individualized, with clear boarders because
it ends in a closed sea, with no tides, where winds have a reduced frequency
and low intensity, conditions which are promoting delta's apparition.
As a result of interactions between river and sea, the Danube Delta divides
itself in two sectors: river delta in the West and river-marine delta
in the East, separated by the line of banks Letea-Caraorman-Crasnicol.
Referring to Danube Delta's genesis and evolution, informations 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.