open TELEMAC-MASCARET The mathematically superior suite of solvers

In user manual, it shows that the unit of "COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION" (COEF1TRAC) is 1/d. Because in "SUBROUTINE SOURCE_WAQ", the code "CALL OS('X=X+C ',X=TIMP%ADR(ITRAC)%P,C=2.3D0/COEF1TRAC(ITRAC)/3600.D0)" contents the unit which is C=2.3D0/COEF1TRAC(ITRAC)/3600.D0. Therefore, "COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION" in module Waqtel it should be "1/SECOND" in unit (ex: COEF1TRAC = 0.02 1/d, so in "COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION" = 0.02*86400, is that right?)

So I confuse how to use which Unit in this case.

Hello,

If I remember correctly, COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION is the famous T90 time (time for the concentration to get to 10% of it's initial value) therefore the 2.3D0.

The units of this value is 1/hours, that is the reason for the /3600.D0

So, if you want for example a T90 value of 10 d^(-1) then COEFFICIENT 1 FOR LAW OF TRACERS DEGRADATION = 240 (24*10).

I hope it helped,

Santiago

Thank you for your helps.