INFLUENCE OF MORPHOLOGICAL CHANGES ON ECOLOGY: A CASCADE OF SCALES
Authors:Silke Wieprecht Organization:IAHR
For the understanding of morphological processes, it is not sufficient to only investigate river sections. On the macro scale, the catchment plays an important role especially for the available quantity of material fluxes and its composition in the river. Intense river works in the last decades and centuries (straightening, reservoirs, dams, dikes etc.) strongly alter the characteristics of our rivers. In particular, the lack of bed load material severely affects the dynamic processes in rivers and ecological important instream structures. In some examples, the attempt is made to enhance the ecological situation in a river by individual river restoration measures. Depending on the availability of material, very different results can be achieved. These effects can also be proven very well with the help of long-term morphological models. Another option is to bring back sediments into the transport cycle, e.g. by flushing reservoirs. On one hand, this can help to increase the morphological dynamics, but on the other hand the grain sorting effect upstream of reservoirs changes the characteristics of the river bed downstream. Due to changes of material composition, the granular structure on the micro and pico-scale of the river bed may be heavily altered. It occurs that, although the meso-scale structure seems to be good, there are still not enough acceptable habitats for aquatic species available. However, alterations on the micro and pico-scale, like colmation and clogging processes, e.g. due to flushing of reservoirs or changes in wash load fluxes from the catchment, can influence the biological communities in rivers. Depending on sediment texture and content of pollutants and/or nutrients, effects like biofilm growth occur, which then additionally alter sediment transport characteristics
Title: INFLUENCE OF MORPHOLOGICAL CHANGES ON ECOLOGY: A CASCADE OF SCALES
Event: 37th IAHR World Congress2017年08月14-18日
Silke Wieprecht

IAHR

niversit?t Stuttgart

Department of Civil and Environmental Engineering

Institute of Hydraulic Engineering

GERMANY

(elected until 2019 R) Statement

(NB R* means eligible for re-election for a second term)
... More
Videos of this author
Related Videos
Paper of this Author
Related Paper
Copyright©2007-2020 MEDCON. All Rights Reserved.