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I am trying to understand the concept of rainfall-runoff component in tel2d. Say I apply hyetogrph to the entire model domain and all boundaries are closed. Could anyone clarify my questions below?

- after applying the curve number runoff model, is the initial abstraction lost from model domain?

- is the runoff calculated for each node or element? Then how is the calculated runoff applied to the domain, to node or element?

Any good reference? The manual does not include sufficient detail.

Also is there plan to incorporate additional infiltration methods, eg Horton, Green-Ampt?

Thanks

Hailiang

Hello!

First of all, you can find more detail regarding the Curve Number runoff model and its implementation in T2D in my article from the Proceedings of last year's user conference (2016). You also have a test case called "pluie" in examples/telemac2d.

To answer your questions:

1/ Yes, the initial abstraction is withdrawn from the rainfall according to the CN model formulation (there is even an option to use another initial abstraction ratio, 0.05, see the article from the proceedings).

2/ The runoff is calculated in the same way as for rain and is applied on each node. If you define your CN locally on the mesh (ie. at each mesh node) you can then model a spatially varying runoff. The rain is however defined as constant in space.

I know that folk at EDF also use Green-Ampt but this has not yet been officially released and I don't know if it will be. The runoff routine (runoff_scs_cn.f) is actually rather simple and one could adapt it to another runoff model with some moderate fortran skills.

Hope this helps!

Happy new year,
Best regards

PL

Thank you so much Pierre-Louis. I have read your paper and it is very helpful to understand the development of subroutine runoff_scs_cn. Can I ask a followup question - to convert the resulting runoff to source terms, does the model convert it to unit m3/s from unit M? If so, we will need an area for each node, how is this area calculated and in which subroutine?

Hailiang

Hello!

Glad that you could find some information in the paper. The rain is introduced as a source term in the structure PLUIE and units are m/s.

If you want to know the corresponding discharge you can multiply it by the area associated to each node, variable V2DPAR (bief object).

Good luck!

Best regards
PL