A major problem with current hydrodynamic and hydrology models is that model representations of a system often lack the detail necessary to truly grasp the movement and supply of flow. However, the problem enters because the scale which most cross-sections are taken in field surveys is too rough to accurately show the bathymetry. Even with a good interpolation between survey lines, there will still be variations that could strongly influence the water movement. A straightening routine may help to mitigate the errors between interpolation points because the routine models points along a smooth curve at differentially small distances. While the bathymetry straightening routine is a simple and efficient method to perform many different tasks, there could be potential problems with it.
Any problem is most likely a function of the grid resolution used.
When applied to a model with a stair-step boundary with a rough grid resolution, the boundary discretization may become jagged which would modify the flow regime. This implies that when a grid is chosen at a sufficient resolution, that the boundary will become smooth and accurately portray the flow. This is true, however, to get a resolution that is sufficient may be expensive. It is at this point that the operator must decide to what degree of resolution is needed versus the cost to attain such a result. The robustness of the straightening routine is only limited by factors of resolution and expense.