How to remove weird "shadow/light" lines?

Hi guys, i have different rooms in my scene and for the floor i used a lot of wooden boards all close together, with a small gap between each one (that's an example of my scene : https://imgur.com/a/Y2zm4kZ). The problem is that, looking at the image, you will see some white thin lines and i wish to remove them, is there a way to do this? Thank you, Matthias.