Author(s)

L. De Doncker, R. Verhoeven, P. Troch, N. Desmet, P. Meire & P. Seuntjes

Abstract

Influence of vegetation on the propagation of flood waves L. De Doncker1, R. Verhoeven1, P. Troch1, N. Desmet2,3, P. Meire2 & P. Seuntjes3 1Hydraulics Laboratory, Department of Civil Engineering, Ghent University, Belgium 2Ecosystem Management Research Group, University of Antwerp, Belgium 3Flemish Institute for technological Research, VITO, Mol, Belgium Abstract Research on river ecosystems asks for a multidisciplinary approach. All components such as water, macrophytes, sediment, suspended solids, etc. play an important role. The presence of macrophytes in rivers has an influence on water levels and flow patterns since a wealthy vegetation growth causes back water effects and consequently higher upstream water levels. In view of this, flood risk increases in periods of higher flows and greater vegetation growth. So, river management also deals with the control of vegetation. Good management contributes not only to the quality of the water and the ecosystem, but also to flood protection. Keywords: backwater effect, ecological modelling, vegetated rivers. 1 Introduction In many lowland rivers in Flanders, a significant increase in macrophyte growth has been observed. This is due to eutrophication and a better water quality (Vereecken et al. [1]) of surface water, which is imposed by the European Union and laid down in the ‘Water Framework Directive’ (2000/60 EG). The directive aims at a better water quality by structural interventions in rivers. A better water quality influences the macrophytes (increasing growth) and so, the drainage of the river. Therefore, the ecological and hydraulic function of the macrophytes has to be understood. The vegetation influences the roughness of the channel bed

Keywords

backwater effect, ecological modelling, vegetated rivers.