HS11.1/NH4.4

Rainfall triggered landslides and debris flows and their effect on erosion and sediment yield in river catchments
Co-Conveners: G. Crosta , P. Frattini 
Oral Programme
 / Thu, 23 Apr, 13:30–15:00  / Room 35
Poster Programme
 / Attendance Thu, 23 Apr, 17:30–19:00  / Hall A
Landslides and debris flows are a hazard in their own right but they are also a means of eroding soil and other material and redistributing it within a river catchment, including injecting it into the river channel. Debris flows may add to their load by scouring additional material along their track while, conversely, material deposited along the track may subsequently be washed into rivers by overland flow. The impact on catchment sediment yield depends on where the landslides and debris flows occur in the catchment, how big they are and whether they connect with the river network. Vegetation cover can also significantly modify both the occurrence of landslides and debris flows and the transfer of sediments. However, there is a lack of research quantifying the relevant processes and impacts and providing the understanding and data needed for the construction of mathematical models. Contributions are therefore requested on the effect of landslides and debris flows on sediment mobilization and transport, including landslide and debris flow characteristics (especially spatial and temporal occurrence and the relationship between magnitude and spatial and temporal frequency), runout distance, transporting capacity, deposition processes and the modifying effect of vegetation. The session may also include the more general characteristics and impacts of rainfall triggered landslides and debris flows. Field and modelling studies, including case studies, are welcome.