Geomorphology of the Sulden River basin (Italian Alps) with a focus on sediment connectivity

Abstract

An area-wide digital geomorphological map consisting of 12,180 non-overlapping polygons was created for the Sulden river basin (South Tyrol, Italian Alps) with the purpose to carry out a GIS-based sediment connectivity analysis. Thirty-one landform types were defined with respect to their role within sediment cascades. As such, the classification and the related symbology partly differ from a traditional geomorphological map where several areal objects are frequently represented by scaled and rotated point symbols. The catchment (∼130 km²), exhibits a high geomorphological variability as well as relatively large glacierized areas. We used the geomorphological map for a first qualitative estimate of the main differences between the two major sub-basins concerning the components of the sediment cascades: while the Trafoi sub-catchment exhibits a high number of small landslides and debris flow channels (i.e. source and transport landforms), the Sulden sub-catchment is rather characterized by large proglacial and talus landforms (i.e. temporary storage landforms).

Keywords

• river catchments
• object-based map
• geomorphic connectivity
• sediment cascade
• glaciated environments