User Forum of Software BASEMENT

LydiaSeitz

User

Registered: 2014-09-08

Posts: 18

1D/2D coupling

Hello everybody,

I have a 1D/2D coupled model for sedimenttransport. After several timesteps the following error message occurs and the model stops:

"A fatal error occured:
There was no next data pair found in the boundary serie. 
The program cannot continue.
We are sorry, but BASEMENT must be terminated now."

I checked all the input files for the boundary conditions in case the hydrograph was not long enough for the long modelling period. But everything is fine.

Does anyone have an idea what this error means?

Best wishes
Lydia

Stephan Kammerer

Developer

Registered: 2015-03-31

Posts: 67

Re: 1D/2D coupling

Hey Lydia,

this error sounds like you chose the wrong boundary condition upstream of your 2D subdomain. Here an example how the boundaries and the coupling block should look like:

BASECHAIN_1D {                                //upstream subdomain   
    HYDRAULICS {
        BOUNDARY {                        //downstream boundary 1D
            type   = coupling_hqrelation
            slope  = 10
            string = downstream
            name   = outflow_1D_hydraulic

    MORPHOLOGY {
        BEDLOAD {
            BOUNDARY {                    //downstream boundary 1D
                type   = coupling_IODown
                name   = outflow_1D_sediment
                    string = downstream

BASEPLANE_2D {                                //downstream subdomain   
    HYDRAULICS {
        BOUNDARY {                        //upstream boundary 2D
            type           = coupling_hydrograph
            string_name    = inflow_2D
            slope          = 2
            precision      = 0.1
            name           = inflow_2D_hydraulic
            weighting_type = area

    MORPHOLOGY {
            BOUNDARY {                    //upstream boundary 2D
                string_name = inflow_2D
                type        = coupling_sediment_discharge
                name        = inflow_2D_sediment

COUPLINGS {
    PARAMETER {
        max_time_level = 1
    }
    COUPLING {
        type                 = sequential
        upstream_subdomain   = region_A        //1D subdomain
        downstream_subdomain = region_B        //2D subdomain
           
        HYDRAULICS {
            upstream_interface   = outflow_1D_hydraulic
            downstream_interface = inflow_2D_hydraulic
        }
        BEDLOAD {
            upstream_interface   = outflow_1D_sediment
            downstream_interface = inflow_2D_sediment

The sequential coupling 1D-> 2D works fine including sediment transport. In the case of 2D->1D coupling sequential, we recently discovered a problem with the sediment boundary 'coupling_IODown' used as downstream bc of the 2D subdomain. This problem is fixed now and 2D->1D sequential coupling including sediment transport will be available with the next bugfix release. Let me know if you need an updated version prior to the next release.

Best regards,
Stephan

LydiaSeitz

User

Registered: 2014-09-08

Posts: 18

Re: 1D/2D coupling

Hi Stephan,

thanks for your reply. Actually the sequential coupling looks like you described above. I have a 2D part within a long 1D model, that means first I have a sequential coupling from 1D -> 2D and than a sequential coupling from 2D -> 1D.

Do you think it´s a problem to couple three models?

It would be great if you could provide me a updated version. So I can try if it´s running.

Best wishes
Lydia