Analysis and Modelling of catchment-scale proglacial geomorphodynamics based on multitemporal airborne and terrestrial LiDAR surveys

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Work package 5 of the PROSA project (High-resolution measurements of geomorpho-dynamics in rapidly changing proglacial systems of the Alps) cooperates with the remaining subprojects in establishing the sediment budget of the Upper Kaunertal study area by regionalising localised measurements of sediment transport by various geomorphic processes along sediment cascades. The main aims of this work package for the proposed follow-up period have not changed since the previous project phase: (1) Continuation of airborne (laserscanning, ALS) measurements; the previously developed method for the enhancement of data accuracy and reliability (e.g. the spatial distribution of measurement errors) will be further refined (2) Integration of the results of all work packages to establish the sediment budget of the study area. In order to reach this aim, the results of measurements conducted on test areas (on the local and hillslope scale) have to be upscaled to the whole catchment (regionalisation), using various methods such as simulation models, statistical approaches, and the analysis of the geomorphological and geotechnical map. The analysis of mapped and modelled sediment pathways leads to important insights into the interaction of various geomorphic processes that form sediment cascades in the study area, and a better understanding of the system (e.g. sediment connectivity). The sediment budget and its parts will be used (i) to assess the relative contribution of glacial and non-glacial processes, (ii) for a comparative analysis of process rates in areas with different periods of time since deglaciation, and (iii) to judge the ratio of sediment transfer within and sediment export from the catchment; the latter quantity refers also to the sediment input to the Kaunertal reservoir.(3) Additionally, this work package continues to be in charge of coordination tasks for all work packages, most importantly the organisation and management of data collection and exchange, and the provisioning of digital elevation models (fine georeferencing, error correction, filtering), including the error assessment.The decision to propose a 9-month follow-up has been brought about by third-party failure to produce data (ALS survey flights) that are essential for pursuing major project goals. The extension of the project period allows to fill these data gaps; specifically, the new data will enable the quantitative comparison of summer- and winter-term morphodynamics on the catchment scale. Moreover, the Gepatsch reservoir will be completely emptied during the proposed follow-up period in spring 2016: A TLS survey of the dry lake bottom, together with the already generated pre-reservoir (1953/54) digital elevation model, will facilitate the exact quantification of the sediment volume (and mean annual sediment yield) deposited in the reservoir, which will form an ideal counterbalance of the sediment budget established by the project.