1Will the health crisis we have been experiencing since March 2020, with the Covid-19 epidemic that has spread worldwide, lead to a radical change in the way we produce the city? This is what a retrospective look at the health crises of 19th century Europe, which led to the invention of new architectural and urban models, invites us to consider. Born in the middle of the century, developed thanks to Louis Pasteur’s discovery in 1865 of the role of microorganisms in contamination and contagion, the hygienist movement was then at the origin of contemporary construction and urban planning. Although the notion of “sustainable development” has been questioned for several decades, this model is no longer adapted to a world in which, soon, 80% of the inhabitants will be urban dwellers. But what kind of “city” will the urban dwellers be? Will they be more or less gigantic metropolises that produce environmental and social inequalities, peri-urban territories nibbling farmland, rural areas as shelters or abandoned by the urban world?

2Prepared for a long time, this issue of the journal Méditerranée aims to contribute to understanding the contemporary issues at stake in the making of our territories, urban, peri‑urban, rural, on a regional or macro-regional scale, in the Mediterranean.

3Here we are faced with a recurring question, but one whose acuity is accelerated by the health crisis. How can scientific dialogue be initiated between disciplines that have taken up environmental issues, particularly those related to climate change and the decline of biodiversity, beyond the possible exchanges between so-called “hard” sciences and human sciences? The responses to our call for contributions testify to the relative unthinking of the researchers or the lack of interest observed in the responses to this proposal. However, we wish to question the work in the field of “sustainable development”, of the conception and management of potentially “sustainable” Mediterranean territories, works marked by disciplinary and interdisciplinary debate and controversy. Do they present a specific character when it comes to Mediterranean countries, do they contribute to clarifying the stakes of the notion of sustainable development as they arise in other geographical areas?

4We approach these questions along three lines :

• The first questions the sustainable city, urban and environment in the Mediterranean
  Let us start from Italy, where David Fanfani, architect-teacher at the University of Florence, proposes, through the notion of “urban bioregion”, the development of possible new relations of economic, physical and energy proximity between town and country within the peri-urban area of Florence-Prato in Tuscany, a fragmented and “deterritorialized” space.
  Continue in Turkey, with Ayşen C. Benli, teacher-researcher in Mersin, for a study on sustainable architecture in the mountain villages surrounding the city of Mersin. This study examines vernacular architecture in the Mediterranean region, with its social, economic, ecological, as well as cultural and spatial character, from a perspective of sustainability.
  Let us broaden our focus, with Thomas Perrin, lecturer at the University of Lille, analyzing the factors of coherence of a macro-region in the Western Mediterranean. Where territorial cooperation has developed, in order to grasp how macro-regionalization, by combining a trans-meso scale and a post-complex logic, would induce a renewal of spatial references and planning policies in the European Union.
  Let us return to Oran, where Amina Louiza Lacheheb, doctoral student, questions the North/South transfer of knowledge in the design of collective housing in a Mediterranean climate, during the modern period, through the work of the architect Louis Miquel, and his “Essai de solution d’un problème d’urbanisme en climat méditerranéen, cité Sellier à Alger”.

• The second axis is concerned with the design of public spaces through the prism of sustainability
  Using Toulouse Métropole as an example, Delphine Chouillou, Senior Lecturer at the School of Architecture of Reunion Island, analyses the urban environmental quality, which is still poorly defined, in the design of public spaces, which are not the priority scales. Consequently, the quality of use of public space is not addressed, thus dissociating environmental quality and quality of use.
  It is in Algeria that Myriam Maachi-Maïza, architect and teacher at the Ecole Polytechnique d’Architecture et d’Urbanisme EPAU, is following in the footsteps of Fernand Pouillon, who favored a picturesque approach borrowed from Antiquity, with the challenge of “Building fast, well and at a lower cost”. This approach, often denigrated, remains surprisingly topical at a time of sustainable development.

• The third axis proposes a reflection on the concepts of governance Mediterranean
  It is in southern Algeria that Mohamed Cherif Adad, architect and teacher at the University of Oum el Bouaghi, questions new experiences of governance in the M’zab Valley, the site of a thousand-year-old urban planning and architectural production, where the adoption of the 1989 Constitution saw the resurgence of ancestral social structures based on the notions of consultation and participation. How did local governance, based on self-construction processes, partially replace national regulations?
  Back to Occitania, with Catherine Bernié-Boissard, Professor Emeritus of the University of Nîmes and Thomas Perrin, Senior Lecturer in Lille, a French region created in 2016 by the merger of two former ones, Languedoc-Roussillon and Midi-Pyrénées, whose various components have been developing at a distance from each other for several decades. How to “make region”, what are the dynamics of recomposition, the inter-territorial articulations? What can be the role of multi-level territorial cooperation in the construction of complex regional groupings?
  All along this itinerary, between countries, regions, architectural, urban planning and social issues, we must grasp some aspects of the question that the health crisis is vigorously raising: how, with whom, with what instruments, what concepts, to invent new models of cities and inhabited territories in the 21st century?