rounding selected faces Hey I created a plane and subdivided it several times till I got a nice grid. Now I want to draw an oasis. I already rounded out the outer shape. I might want to do it several times and I rounded it by hand. Is there an automatic way? I want to repeat it for the middle area now. I will have to do it for a much bigger area soon.

Is there a way to select only the green area? I can get the selection in the UV Editor as the "sand" area is on a yellow colour and the "gras" area is on a green area. Can I get the UV Editor selection to the object editor? Is there another way?
Check out the loop tool plugin, it comes along the with blender.

Just enable and have a try. You seem to have used lot of subdivision, which makes the task a little difficult.