11:15 AM - 11:30 AM
[HTT13-03] Sediment Transfer Rates post-Deglaciation on New Zealand Alpine Fans - Field data, Laboratory and Numerical Simulations
Keywords:alluvial fan, sediment flows, Sediment hazards, Fox Valley, New Zealand, Numerical simulation
In the present contribution, the author is investigating the role of local sediment stock on the growth rate of Alpine-fans in deglaciating valleys on the West coast of the South Island of New Zealand, using a combination of field investigation, laboratory simulation and numerical modeling.
In the field, GNSS RTK combined with UAV photogrammetry was used to model the 3D topography, and the growth rates were calculated from historical archives showing the glacier retreat. From the field observation, in-valley benches of sediments inherited from the glacier and the valley interaction were added to a table-top flume to simulate the growth of a fan, with and without those, for constant slopes and discharges. The parameters extracted from these simulations were then applied to numerical models of fan development, in order to relate the sediment discharge, the fan growth rate and the spatial distribution of sediments’ volume.
The results from laboratory fan experiments were used to feed the numerical model, in order to explain the field observations.