title: Current status and restoration options for floodplains along the Danube River.
abstract: Floodplains are key ecosystems of riverine landscapes and provide a multitude of ecosystem services. In most of the large river systems worldwide, a tremendous reduction of floodplain area has occurred in the last 100 years and this loss continues due to pressures such as land use change, river regulation, and dam construction. In the Danube River Basin, the extent of floodplains has been reduced by 68% compared to their pre-regulation area, with the highest losses occurring in the Upper Danube and the lowest in the Danube Delta. In this paper, we illustrate the restoration potential of floodplains along the Danube and its major tributaries. Via two case studies in the Upper and Lower Danube, we demonstrate the effects of restoration measures on the river ecosystem, addressing different drivers, pressures, and opportunities in these regions. The potential area for floodplain restoration based on land use and hydromorphological characteristics amounts to 8102 km(2) for the whole Danube River, of which estimated 75% have a high restoration potential. A comparison of floodplain status and options for restoration in the Upper and Lower Danube shows clear differences in drivers and pressures, but certain common options apply in both sections if the local context of stakeholders and societal needs are considered. New approaches to flood protection using natural water retention measures offer increased opportunities for floodplain restoration, but conflicting societal needs and legal frameworks may restrict implementation. Emerging issues such as climate change and invasive non-native species will need careful consideration in future restoration planning to minimize unintended effects and to increase the resilience of floodplains to these and other pressures.
authors.affiliation: WasserCluster Lunz GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria; University of Natural Resources and Life Sciences, Institute of Hydrobiology and Aquatic Ecosystem Management, Max-Emanuel Straße 17, 1180 Vienna, Austria. Electronic address: thomas.hein@boku.ac.at.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hein
authors.affiliation: FLUVIUS Floodplain Ecology and River Basin Management, Hetzgasse 22/7, 1030 Vienna, Austria. Electronic address: ulrich.schwarz@fluvius.com.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Schwarz
authors.affiliation: University of Natural Resources and Life Sciences, Institute of Water Management, Hydrology and Hydraulic Engineering, Muthgasse 107, 1190 Vienna, Austria. Electronic address: helmut.habersack@boku.ac.at.
authors.forename: Helmut
authors.initials: H
authors.lastname: Habersack
authors.affiliation: Danube Delta National Institute for Research and Development, 165 Babadag street, Tulcea 820112, Romania. Electronic address: iulian.nichersu@ddni.ro.
authors.forename: Iulian
authors.initials: I
authors.lastname: Nichersu
authors.affiliation: WasserCluster Lunz GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria; University of Natural Resources and Life Sciences, Institute of Hydrobiology and Aquatic Ecosystem Management, Max-Emanuel Straße 17, 1180 Vienna, Austria. Electronic address: stefan.preiner@boku.ac.at.
authors.forename: Stefan
authors.initials: S
authors.lastname: Preiner
authors.affiliation: Biological and Environmental Science, University of Stirling, Stirling FK9 4LA, Scotland, United Kingdom. Electronic address: n.j.willby@stir.ac.uk.
authors.forename: Nigel
authors.initials: N
authors.lastname: Willby
authors.affiliation: WasserCluster Lunz GmbH, Dr. Carl Kupelwieser Promenade 5, 3293 Lunz am See, Austria; University of Natural Resources and Life Sciences, Institute of Hydrobiology and Aquatic Ecosystem Management, Max-Emanuel Straße 17, 1180 Vienna, Austria. Electronic address: gabriele.weigelhofer@boku.ac.at.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Weigelhofer
mesh_terms: D001317:Austria; D057231:Climate Change; D003247:Conservation of Natural Resources / Q000379:methods*; D017753:Ecosystem; D058735:Environmental Policy; D052918:Environmental Restoration and Remediation; D055868:Floods; D005858:Germany; D045483:Rivers / Q000737:chemistry*
keywords: Danube river; Flood protection; Floodplains; River restoration; Water framework directive