I have found that if you combine a 2D raster with a raster created from 1D cross sections, the HECRAS will produce a separate results file for each raster when recalculating results for export using the manage results option. Is there a way for HECRAS to recognize the merged rasters as one raster and produce one set of results as it becomes a difficult task to perform raster calculations in GIS with multiple raster output files.