How to make the Earth more habitable ? Benton MacKaye's Geotechnics

International audienceFor Benton MacKaye, as well as for many of his contemporaries of the 1920's, it was becoming urgent, in order to control the evolution of urbanization, to work not only at the metropolitan scale, but at the larger scale and dimension of the environment as a whole. Environment was then defines by Benton MacKaye as "the common substance of our total human life" . Nevertheless, succeeding in such a project implied, for MacKaye, to work on a new science, named Geotechnics, as defined: "the applied science of making the earth more habitable." "Geotechnics concerns habitability" explained MacKaye; and "there are three kinds of habitability - I, physical, II, economic, and III, social. These are concerned, essentially, with three kinds of flow: Water (and attendant soil); Commerce (raw and finished materials and energy); Population (and attendant development)." Are we so far from our current concerns? Is MacKaye's geotechnics so far from the present ideas and actions in favor of a sustainable development of our urbanized territories? A region was defined taking in consideration the three kinds of habitability. A project done according Geotechnics principles had to integrate, within the same thought, geographical, economical, sociological, cultural, natural, data or facts, as well as all the technological advances realized. Such are the foundations of the Regional Planning in the United States in the 1920's, with the hope that it would be the way to implement a development more respectful of this "ball", the Earth, on which we can't lose sight of. These principles has been the ones used for the Appalachian Trail project, as well as for the studies done for the Tennessee Valley Authority and the Mississippi watershed