When plotting the Depth layer for 2D areas in RAS Mapper, this layer does not take into account bed change in mobile bed simulations. Therefore, in cases where the bed change is significant, the water depths will be significantly incorrect results. There is currently no workaround for this issue.
Profile Line Flow Hydrographs
Flow hydrographs may be computed across profiles in RAS Mapper. The user output Face Flows, the computed flows from the engine are utilized. However, if the Face Flows are not output, the flows at faces are computed as the face velocities multiplied by the initial face areas. Since the face areas change during mobile bed simulations, the face flows are not correct for mobile bed simulations. The work around for this issue is for the user to output Face Flows. The Face Flows output dataset is turned on in the Unsteady Flow Analysis editor, by selecting Options | Output Options and then navigating to the HDF5 Write Parameters tab shown in the figure below.
Profile Line Terrain Elevations
When plotting a profile plot of terrain elevations either by themselves or with other variables such as the water surface elevation, the terrain elevations represent the initial bed elevations and do not account for the bed change during mobile bed simulations.
