GMS, SMS, and WMS User Forum

# leikvinen

Members

2

1. ## A confirmation on RMA4-concentration issue

Dear co-modellers, I am working on a dynamic RMA2/RMA4 problem to track the path and dilution of a sewage outlet. I do have a time step equal to 0.5 hrs. Lets say, I also have a outlet flow giving 1 thousand bacteria/second. To get reasonable (practical) results on the dilution for this problem, I do have to multiply the outlet flow with 30*60=1800, to put in 1800 thousand/ 0.5 hrs into the BC-card? Is this the correct way of thinking? With a constant BC of 1800 000, will then 1800 000 bacteria be injected into the model domain every time step (=every 0.5 hrs)? Hope you are able to confirm my thoughts... Best regards Leikvinen
2. ## Using whole amplitude of tidal variation in water surface elevation forcing?

Dear you! Description of task: I am now using RMA2 with SMS 10.0 to model a relative complex area close to a river mouth. For simplicity, I regard the water flow from the river as constant. There are 4 fjord arms outside the river, from where I do have current measurements to force the model. I do find a strong tidal signal. I choose to put given tidal elevation data given from public available tables at the outermost oceanic boundary, towards the ocean, to be consistent with the recommended way of running RMA2. Comment: I do have to manually adjust the BC-files, where the current switches direction, and add the value of "pi" to the angle. I reckon this must be a straightforward task for the RMA-designers to improve!?! Question: I do model only the surface layer, say the upper 10 meters. I calculate the water fluxes of the 3 boundaries and assign them as BCs (current * area). Then I wonder if it is correct to use the whole tidal elevation amplitude for the water surface elevation forcing, or only a fraction of it? I am modelling only the upper 10 meters out of a total depth of about 100m. Do you have any guidelines or mathematical approach to answer this question? Hope anybody is able to help! Best regards Leikvin
×