I want to model a system that consist of glacifluvial sediment deposited in a NE, SW orientation (this is also the direction of GW-flow), using MF6 disv-grid through Flopy. In order to reduce risk of numerical instability, I want to rotate the model grid 45 degrees counter clockwise. However, rotating the model grid causes the grid to be displaced in relation to model pertinent information, such as digital elevation maps, boundary conditions, and observation data.
What is the recommended approach for working with rotated model grids? Is it possible to rotate the grid, refine the grid, and then rotate it back to its original position before appending boundary conditions and elevations? Or is the modeller expected to rotate all other data as well (i.e. boundary conditions, observation data, e.t.c.)? If the latter is true, then that would mean a lot of extra work for a complex model.
Ultimately, I want to perform parameter estimation / history matching using PEST/PEST++. What could be the consequence of having a rotated model grid when performing model calibration?
Very curious to hear your opinions and recommendations.