Artist works that manipulate natural earth and stone, altering the terrain of the land itself for artistic purposes. For large-scale outdoor works that otherwise exploit or incorporate aspects of their sites, use the more general term "environmental art." For the results of grading, trenching, or embanking earth, for utilitarian purposes, use "earthworks (engineering works)."

Source: Art & Architecture Thesaurus

http://vocab.getty.edu/page/aat/300047857