On the status and future of water bodies - processes, trends and needs for action
Since the beginning of the systematic regulation of rivers a continuous degradation of water bodies can be observed. One indicator is e.g. the dramatic reduction of the number of fish species and the biomass, so that river restoration has been pushed since the several decades. At the same time further impacts could be observed. These are the changes related to hydropower, navigation or floodrisk management. Additionally landuse and climate change lead to significantly changed boundary conditions at catchment scale. As a consequence discharges and whole hydrographs have been modified. Only recently more awarenees is given to the changed sediment regime leading to an increasing surplus and deficit of material, causing reservoir sedimentation and river bed erosion. All this leads to a decline of morphodynamics and a degradation of habitats. Finally ecosystem services are affected. On top of this the polution e.g. with microplastics adds to the cumulative impacts. The lecture discusses relevant processes and trends. Finally the needs for action are formulated and illustrated with the example of the UNESCO IHP World´s Large Rivers Initiative.
Host: Martin Pusch