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Hi,

I'm modelling a river in TELEMAC-2D coupled with Sisyphe with 10 sediment diameters classes.
I'm prescribing a solid Discharge at the inlet but I can't figure out how its works. I'm setting QBOR=8.2 m3/s at the inlet (Boundary 1) with a coupling period for sisyphe = 5 and the results shows variation of the solid discharge at the inlet when it should be constant and equal to 8.2 m3/s.

Time step 5:
MASS-BALANCE (IN VOLUME, INCLUDING VOID):
SUM OF THE EVOLUTIONS : 23.48111 M3
BOUNDARY 1 BEDLOAD FLUX = 73.49021 ( M3/S >0 = ENTERING )
BOUNDARY 2 BEDLOAD FLUX = 1.649348 ( M3/S >0 = ENTERING )
TOTAL BEDLOAD FLUX = 75.13956 ( M3/S >0 = ENTERING )
LOST VOLUME : 0.3197442E-13 M3 ( IF <0 EXIT )


Time Step 15:
MASS-BALANCE (IN VOLUME, INCLUDING VOID):
SUM OF THE EVOLUTIONS : 0.5395875 M3
BOUNDARY 1 BEDLOAD FLUX = 1.571855 ( M3/S >0 = ENTERING )
BOUNDARY 2 BEDLOAD FLUX = 2.129002 ( M3/S >0 = ENTERING )
TOTAL BEDLOAD FLUX = 3.700857 ( M3/S >0 = ENTERING )
LOST VOLUME : 0.9570122E-13 M3 ( IF <0 EXIT )

Time step 25:
MASS-BALANCE (IN VOLUME, INCLUDING VOID):
SUM OF THE EVOLUTIONS : -0.1060223 M3
BOUNDARY 1 BEDLOAD FLUX = -3.760100 ( M3/S >0 = ENTERING )
BOUNDARY 2 BEDLOAD FLUX = 2.712149 ( M3/S >0 = ENTERING )
TOTAL BEDLOAD FLUX = -1.047950 ( M3/S >0 = ENTERING )
LOST VOLUME : -0.1828260E-12 M3 ( IF <0 EXIT )

Time Step 75:
MASS-BALANCE (IN VOLUME, INCLUDING VOID):
SUM OF THE EVOLUTIONS : 0.9693890 M3
BOUNDARY 1 BEDLOAD FLUX = 0.6179927 ( M3/S >0 = ENTERING )
BOUNDARY 2 BEDLOAD FLUX = 9.790858 ( M3/S >0 = ENTERING )
TOTAL BEDLOAD FLUX = 10.40885 ( M3/S >0 = ENTERING )
LOST VOLUME

I can't understand why BOUNDARY 1 BEDLOAD FLUX its changing every time step when is a constant solid discharge of 8,2 m3/s.

I saw the conlit.f file and found this:

IF(NSICLA.GT.1) THEN
DO I=1,NSICLA
DO K=1,NPTFR
IF(NUMLIQ%I(K).EQ.IFRLIQ.AND.
& LIQBOR%I(K).EQ.KENT) THEN
QBOR%ADR(I)%P%R(K)=AVAIL(NBOR(K),1,I)*T1%R(K)
ENDIF
ENDDO
ENDDO

If AVAIL is the fraction of each sediment class, T1 might be QBOR (It come from DSIMP.f) read it from the preescribed discharge value set by the user. Why bedload flux at the inlet changes at every time step?

Best regards,

Gonzalo