The mesh resolution controls only the precision of the 3d contours, nothing to do with textures.
As I've said, the difference in quality will always be there because at a certain point the higher resolution ground textures will end, and the photorealistic background will take over. So, if it's the transition that is annoying you, you should LOWER the texture resolution (not the Mesh resolution, the max Texture size) but, I'm not sure if it's a good idea to lower the quality of the whole airport, so that it would blend better with the surrounding area.