We tried using the "Link 2D2D Approach == Method B" command and found that the mass balance was high (40%). Specifically, nealry all of this mass is lost in the 2D/1D linkage (as shown by the 2d1d.MIF data). When we run without the above command, the total mass balance is still not great except most of the lost mass is now in the 1D nodes (only 1D in the model is the hidden link nodes for 2d2d). Any ideas appreciated ?
Details: 40m grid with 15s TS linking to 10m grid with 3s TS. Max depths of about 4m. Tidal inflows only to begin with (and MB with these flows only). Set d=0, a=10 and used a single 2d2d line across floodplain with about 8 vertices where najor changes of grade / banks occur.