Terrain modeling

[array81]

I have created a terrain by TopoShaper plugin and isocontour.
Part of the land is flat, but one part is uneven.
I have to edit the uneven part of the land to make it flat. I have already tried to use the "model" tool from sandbox toolbar but also if I try to recude radius I cannot get a good result because I must move least 3 edges.

Is there a way to accurately model the terrain?

[Rich O Brien]

There's various tools available to flatten meshes. Artisan or Vertex Tools would be my weapons of choice.

[pilou]

There is also Drop Vertices by TIG