User Forum of Software BASEMENT

Boris

User

Registered: 2017-03-27

Posts: 1

Sediment deposition

Hi

which are the parameters that are influencing the erosion/deposition a part of Kstr and the slope of the system.

Indeed, I am simulating a river system with inflows of max 200 m3/s (24h hydrograph with max 200 m3/s) , average slop of 1.5% and Kstr around 40.... with Smart Jaggi single grain. A part this I kept almost all default data, so not much modification.

but my sediment balance is showing me that only 10 % is flowing out... therefore 90% is deposited inside my system.

Observation, based on a similar 1987 event, didn't show any deposition ... all has been transported through the system.

In addition, I have a question regarding the "Limit bedload wetted", when I am enabling it "ON" my model is running but no data are recorded, no Qin, Qou, Qsed in or Qsed out. Balance 0.
How should it be used and in which case?

Thanks for highlighting me.

Regards

Boris

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 127

Re: Sediment deposition

Hi Boris,

I would not recommend the smartjaeggi formula for 2-D simulations because it strongly depends on bed slope.
Check for e.g. mpm or rickenmann in the manual and you will see the important parameters.
Indeed bed roughness is key to determine Shields parameter, and kst of 40 seem rather high for slope of 1.5%...

limit_bedload_wetted = on is recommended, as otherwise you might have sediments inflow into certain cells but no outflow (local deposition).
In your case it looks like you have no fully wetted elements at the boundary. Maybe consider to refine your mesh.

Hope this helps!
Best, Lukas