How can I place my texture tiles properly in my landscape material to correspond to its UV?

I generated a Landscape from a height map and that worked perfectly how I wanted.

how can I piece together my 4 textures inside a material to be used on my landscape?

each texture corresponds to one of the colors in the picture, how can I place them like that inside the material editor so once i apply the material on the landscape the textures will be placed correctly?

Thanks again Guys!