Hi, I am currently working on a 1D to 2D model and there seems to be an issue with one specific reach in the 1D portion of the model as the volume accounting error along this reach is 27.59% with a maximum WSE error of 7.091. I have tried editing the lateral to structure avoid any low points along the canal, increasing/decreasing the time step, adding more cross sections to the reach, using the normal 2D equation for the lateral structure instead of the weir equation, reducing the weir coefficient, increasing the lateral stability factor to 3, and increasing the initial flow in the reach, however none of that seemed to work and some of the changes actually made my model go completely unstable. The results also give a warning that it has extrapolated above the cross section table for Cross sections and the rating curve for bridges along the reach. If anyone has any ideas on ways that I could possibly reduce this error any suggestions would be greatly appreciated.
Thanks