Embanking the Lower Danube: From Natural to Engineered Floodplains and Back

Anthropogenic intervention along the Danube floodplain has occurred in various degrees since ancient times. Early in this history, small and localized changes were linked to fishing as floodplain lakes and channels constituted a permanent and trusted source of fish. Large-scale, intense changes occurred primarily during the communist period when most of the floodplain was used for agriculture. As a result of this phase, 3250 km of artificial levee were constructed on the main course of the Danube, of which more than 1100 km are located in Romania. By the end of the 1980s, the area affected by anthropogenic intervention in the floodplain amounted to 433,957 ha, represented by 56 embanked enclosures. Only a small part (79,943 ha) remained under natural conditions, primarily the mouths of tributaries and the “Small Islet of Brăila”. In time, the narrowing of the streambed by anthropogenic levees led to an increase in current velocity and significant erosion of the riverbed. The damming of Danube at the Iron Gates Gorge and of its major tributaries led to the creation of 340 artificial lakes along their courses and lowered drastically Danube’s sediment discharge that feeds the current floodplain. In addition, fertilizer-aided intensive agriculture on the floodplain has fundamentally changed its soil regime.