Do that. But obviously raise the displacement at one end.
You'll probably want to keep the height gain uniform (so it doesn't just look like a bumpy dirt ramp with the wrong texture applied) so raise each profile block by X units per sloped "step" (to how ever steep you want the slope), and align the displacement vertices with the edges of the raised blocks.
At the very least it explains the physical process that the program Grim posted performs for you.
A Boojum Snark: Don't listen to grazr he is probably drunk