User Forum of Software BASEMENT

Marulke

User

Registered: 2015-11-14

Posts: 24

Does "local_slope_correction" work with Engelund Hansen formula?

Hi,
I need a clarification regarding the "local_slope_corrrection" in the BEDLOAD\FORMULA block.

As I understand it, this prarmeter is used to reduce the critical Shields number for particles on a side slope. I.e. particles on a side slope (banks) start to move at a lower shear stress compared to particles on a horizontal bed.

Question:
1) How is this parameter used in combination with Engelund Hansens bed load formula? I believe that Engelund Hansens formula does not include a critical stress. Does BASEMENT still apply some slope correction, or is local slope correction ignored for EH?

2) Same question as above, but for Wilcock Crowe (wich has a reference stress instead of a critical stress)?

Kind regards,
Marulke

Lukas Vonwiller

Developer

Registered: 2014-09-04

Posts: 130

Re: Does "local_slope_correction" work with Engelund Hansen formula?

Hi Marulke

'local_slope_correction' does correct the critical shear stress due to a local bed slope (longitudinal bed slope in flow direction AND lateral bed slope).

To answer your questions:
(1) Since the EH-formula does not consider a critical shear stress, 'local_slope_correction' will have no effect

(2) I assume that here also it will have no effect. At least to my understanding, it would make no sense to apply this concept to W&C formula.

hope this helps!
Best, Lukas

Marulke

User

Registered: 2015-11-14

Posts: 24

Re: Does "local_slope_correction" work with Engelund Hansen formula?

Hi Lucas,
thank you for the clarification.

Regards,
Marulke