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Natural environment

Physical geography

The course of the Danube below Budapest has been greatly influenced by geomorphic events approximately 30 million years ago, when the Alps, Carpathian and Balkan mountain ranges were pushed up by the collision of the African and European tectonic plates. The Carpathians rose in a large curved S-shaped formation, passing through what are nowadays Slovakia and Romania, while the Balkans continued this curve through Serbia and Bulgaria. The Danube has cut its way between these two mountain ranges by way of the Iron Gates gorges.

Small farmers in Romania still make extensive use of horse-drawn carts

Either side of this mountain barrier, the river has created two extensive basins. The Pannonian basin takes up most of central Hungary (where it is known as the Great Hungarian plain) and extends south into Slavonia (eastern Croatia) and Vojvodina (northern Serbia). East of the mountains is the Wallachian basin, taking up the southern part of Romania. In both these basins the river has over many centuries changed its meandering course as a result of frequent flooding. This has created a swampy flood plain close to the river. Bounding this flood plain and set back from the river sometimes by as much as 30km is the low rise (between 30–50m) of a river terrace leading to a fertile plateau of sandy loess (fine wind-blown soil) formed from silt brought down by the Danube. The construction of extensive flood dykes in the Pannonian basin and the Iron Gates dams, constructed in the late 20th century between the two basins, have permanently changed the pattern of regular flooding. This has enabled the flood plains to be developed agriculturally. Farming on the plateau above the river terrace is typically arable, with wheat, maize, oilseed rape and sunflowers the main crops cultivated in very large farms. On the floodplain, smaller farms grow a mixture of crops, fruit and vegetables in addition to raising livestock. Traditional farming methods are followed in many areas, including local styles of haystacks in Serbia, mobile beehives pollinating the crops and extensive use of horse and carts in Romania and reed cultivation in the Danube Delta.