Elbe river flood peaks and postwar agricultural land use in East Germany.

Collectivization of farmland since the 1950s has changed the agricultural land use in former East Germany. Single fields on the collective farms became increasingly large and were cultivated with increasingly heavy farm equipment. This led to large-scale physical degradation of arable soils, enhancing the formation of surface runoff in periods with prolonged and excessive precipitation. The extent to which this development may have affected the discharge behavior of the main East German river, the Elbe, has so far not been studied. We analyzed the flood peaks of the Elbe during the past century (1900-2000). The flood discharge behavior of the Elbe has apparently changed significantly since the 1950s. Although climate changes may be involved, we conclude that the Elbe flood peaks, recorded since 1950, are related to the changes in postwar agricultural land use in former East Germany. To restore the degraded farmland soils, a change in agricultural land use may be necessary.