Flood history and river regulation

Abstract

Historical sources on the indirect consequences of Drava floods are available from medieval times and in more detail since the 16th century. The first documented flood on the Upper Drava occurred on 15 June 1553 and on the Lower Drava on 2 June 1770. The approximate sequence of flood events can be deduced from the summary table of historical floods. Several case studies describe the relocation of settlements following devastation by major floods. Flooding has ever been both curse and blessing for the population of neighbouring areas: it not only presented a threat to lives and properties, but also fertilized lands with nutrient-rich alluvial deposits. In the course of history people have learnt to fight floods and regulate streams employing various hydrotechnical measures, which brought about both beneficial and detrimental changes in the hydrography and ecology of riverine environments.