Fluvial Transport Process Alterations in partly Glaciated Catchments forced by Climate Change

What happens to alpine rivers if glaciers disappear and the Alps became almost ice-free? It is already accepted in science that ice-free Alps are no longer a utopia by the end of the century. Therefore, the question arises, how will formerly glaciated catchments affect high-alpine fluvial processes and sedimentological conditions? These changes are shifting boundaries for the entire riverine landscape and its development including hydropower use. The research project FRAGILE (Fluvial Transport Process Alterations in partly Glaciated Catchments forced by Climate Change) aims to quantify the current, and to predict the future impact of climate change on fluvial sediment transport using the Vent/Rofenache (Ötztal valley) and the associated sediment supply to the downstream Inn River. The central aim is to determine the interaction between glacier retreat and the changing sediment regime and to close the gap between glacial and river research. In order to achieve this aim, (i) various existing monitoring data will be integrated to a common database, (ii) a process-based cascade model for sediment transport further adapted and (iii) a conceptual model for the ´need´ and ´supply´ for alpine rivers will be developed. The proposed outcomes will not only strengthen the process understanding but also validate the existing data. Through the statistical data analysis, semi-automatic GIS applications, quantified sediment transport, flow and glacier monitoring as well as metrological data, consequences for the environment will be predicted. Especially, the forecast model based on the measured and predicted changes in sediment supply will allow the estimation of climate change impacts in similar catchments. This will be supported by a guideline of how such monitoring should be set up in similar catchments. Thus, due to the “fragile” connection between glaciers and rivers via the sediment supply, the long-term changes in the sediment budget should be studies in detailed based on the selected interdisciplinary approach, which the FRAGILE project pursues.