Abstract
Within the presented thesis the sediment connectivity of the Sulden / Solda catchment (Eastern Italian Alps) is investigated by means of a geomorphological map, a graph-theorybased connectivity assessment and a multi-temporal analysis of morphological changes with the proglacial area. A particular focus is laid on the identification of potential climate change induced impacts on the sediment transfer patterns. For instance, phenomena as glacier retreat, permafrost thawing and the expected higher frequency of meteorological extreme events may have a significant effect on sediment availability and transport in glacierised, high mountain catchments. To obtain detailed insights and knowledge on the sensitivity of the study area to such external forcing, a sediment transport network was created based on remote sensing data and a previously developed geomorphological map. This sediment transport network was built up by eight different transport processes. Successively, it was adapted for six meteorological scenarios for which I distinguished between snow- and glacier-melt season and respectively average, rainstorm and heat wave conditions within these seasons to investigate changes in connectivity. The results, which were compared for two morphologically strongly diverging major sub-catchments, indicate that the changes in connectivity induced by the occurrence of extreme meteorological events depend largely on the geomorphological setting of the respective catchment. However, the strongest increase in connectivity to the outlet of the catchment was found to occur for rainstorm conditions during the glacier-melt phase for both sub-catchments. The multi-temporal analysis of morphological changes in the proglacial area was conducted by differencing four digital elevation models of the years 2013, 2016, 2018, 2019, respectively. Within this analysis I could identify that in particular changes occurring at the glacier mouths resulted in a reduced or increased sediment connectivity, which thus affected as well downstream areas. Furthermore, the mobilization of proglacial deposits by means of e.g. gravel bank collapses due to undercutting of proglacial stream or the effects of a partial collapse of a lateral moraine induced by a heavy rainstorm event, have been recognized.
Concluding, it can be stated that climate change-related processes may have a strong impact on sediment connectivity and sediment transfer patterns in glacierised high mountain catchments. However, based on the findings of this thesis it should be stressed that the degree to which the catchment is impacted is strongly dependent on the geological and geomorphological setting, the structural configuration of the proglacial area and the morphological dynamics occurring at the glacier margins.