| dc.description.abstract | The Groenlose Slinge is a stream in the east of the Netherlands that was re-meandered between spring 2007 and summer 2008. Re-meandering is frequently done in the Netherlands because it has a positive effect on the ecology. However, the effect of vegetation on the bank erosion pattern of (re-) meandering streams is not clear. The main aim of this research is to analyse the effect of vegetation on the bank erosion pattern and the lateral migration rate of the Groenlose Slinge. Secondly, the morphological evolution of the Groenlose Slinge is studied.
Fieldwork was carried out and also the two dimensional Bank Stability and Toe Erosion Model (BSTEM) was used. Moreover, the results of former studies of the Groenlose Slinge were used.
Bank erosion only takes place in outer bends and never in inner bends, indicating that the channel was dug wide enough. No effect of most grasses, herbs and young trees on the erosion pattern is found; the added strength of these types is too small to overcome the unstable bank. Only reed, bulrush and mature forest can prevent erosion in outer bends. As a result, only these vegetation types can influence the pattern of erosion in outer bends. No different effect of different vegetation on the migration rate of the Groenlose Slinge was found. The most obvious morphological evolution is that between 2008 and 2011 on average 1.5 m2 net deposition per metre length took place. The deposition leads to higher banks and to narrower channels in 2011 than in 2008. Also most bends of the Groenlose Slinge became sharper which lead to higher water depths.
Thus, concerning the main aim of this research, it can be concluded that the bank erosion pattern of the Groenlose Slinge is globally reflected by the pattern of outer bends and that vegetation has no effect on the lateral migration rate. Concerning the second aim of this research, it can be concluded that net deposition took place between 2008 and 2011. | |
