User Forum of Software BASEMENT

Marulke

User

Registered: 2015-11-14

Posts: 24

Bed load flux: Curvature effect and effect of lateral slope?

Hi,
I have a question regarding the direction of the bed load flux.

As I understand section "1.2.3.2.1 Components of the bed load flux" in the reference manual, the bed load flux in x-direction consists of the following:
1) Bed load due to flow in x-direction
2) Lateral transport in x-direction due to lateral bed slope
3) Lateral transport due to curvature effect
4) Gravity induced lateral transport (unstable slopes)

Question 1
Equation 1.80 in the reference manual does not include lateral transport due to curvature effect (point 3) above). I think it should be, am I mistaken?

Question 2.
I assume that lateral transport due to both bed slope and curvature effect are (more or less) independent. You can have horizontal bed and lateral movement due to curvature effect. Or you can have lateral movement due to a sloping bed without a curve.

If I understand the setup for the block DIRECTION in the bmc, you can either choose lateral transport due to sloping bed OR lateral transport due curvature effect. But you can not activate both at the same time. Correct?

I am thinking that both phenomenon may occur at the same time? Why cant both be activated simultaneously for calculating the lateral bed load movement?

Thanks,
Marulke

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 127

Re: Bed load flux: Curvature effect and effect of lateral slope?

Hi Marulke

I agree that related to question 1, the qb,curv is missing in the equation. It is in the description below, but was obviously forgotten in the equation 1.80.

To your second question: The DIRECTION is repeatable, hence you can define a DIRECTION block for lateral transport due to sloping bed AND a DIRECTION block for lateral transport due to curvatue effect!

Hope this helps!
cheers, Lukas

Marulke

User

Registered: 2015-11-14

Posts: 24

Re: Bed load flux: Curvature effect and effect of lateral slope?

Great,
that solves the problem.

I did not think I could repeat the DIRECTION block.

Thanks,
Marulke