Modder luxor8071 has released a new texture pack for Fallout 4 that aims to improve its landscape textures. According to its description, the FO4 Landscape Overhaul HD mod is a realistic and high detailed HD texture overhaul and all ground textures are in 2K resolution, featuring diffuse, normal and specular maps.
Source: N4G PC FO4 Landscape Overhaul HD mod brings 2K HD landscape textures to Fallout 4