The Danube River Basin

The Danube is the European river par excellence; a river that most effectively defines and integrates Europe. It links more countries than any other river in the world. The Danube River Basin (DRB) collects waters from the territories of 19 nations and it forms the international boundaries for eight of these. The river's largely eastward course has served as a corridor for both migration and trade and a boundary strongly guarded for thousands of years. This chapter provides an overview of the DRB, including the three main sections: upper, middle, and lower Danube, the delta and 11 major tributaries. Culturally and biologically, the river has always been a separator as well as a connector. It served as a migration corridor for organisms and cultures and has been an area of dispute as well as a major melting pot of cultures. It is also listed as one of the world's top 10 rivers at risk. The development of the Trans-European Network for Transport, the ongoing construction of small- and medium-sized hydropower plants along its tributaries, bed incision, truncation of sediment transport, and rapid land-use change within the basin pose major threats.