Fairly new to blender so I hope I am giving enough detail on my issue. I have brought in a digital elevation model to blender and displaced it to give the landscape a 3D appearance. I subdivided the mesh plane to the extent my computers memory usage can handle. I then added an image file to drape over the landscape and used "smooth shade". In my viewport, before I render(photo 1), it appears the landscape is mostly smooth, you can hardly see any tiles, and if you can they have smoothed edges and don't look like a problem (as seen below). However, once I render my project, the tiles become unsmooth and are much more noticeable and cast shadows that make it look like there are a bunch of tiny squares/tiles on my image (photo 2, rendered image).
I tried turning on and off "use tiling" and that did not help. I also tried subdiving the mesh plane again, however my computer could not render the image after that, but I do not suspect it's a matter of how many subdivisions it has. The viewport model before rendering looks great, but after rendering the tiles become more pronounced.