Cette thèse traite de la manière dont les Tandroy, population originaire de l’extrême Sud de Madagascar, produisent leurs identités collectives en situation de migration urbaine dans la ville de Toliara. Les Tandroy, qui vivent depuis près d’un siècle en situation de circulation à travers l’île, sont le plus souvent assignés à un statut de migrants précaires, pour lesquels la ville demeure un espace étranger. Je montre, à travers une ethnographie de situations rituelles, comment cet état de la migration peut être considéré comme un espace de transition, dans lequel se joue le passage d’un état de mobilité à un état d’ancrage. Je montre également comment ce passage implique la remise en cause d’une identité collective construite avec la colonisation, et cristallisée au début des années 1970, époque où sévit une révolte paysanne menée par Monja Jaona, leader politique tandroy d’envergure nationale. Mes enquêtes se situent dans deux domaines, celui de la politique, et celui de la possession. Dans les deux cas, l’ancrage en ville s’exprime de manière paradoxale à partir du maniement de symboles ancestraux, pourtant fragilisés par le phénomène migratoire et jugés inadaptés à l’espace urbain : le poteau sacrificiel hazomanga, et l’esprit de possession kokolampo. Je m’intéresse à la manière dont ces éléments participent à l’élaboration de constructions symboliques confrontant des catégories identitaires articulées à l’expression d’une mémoire collective, et porte une attention particulière à la musique produite dans les situations ethnographiées, laquelle peut amener à une forme alternative de relation à l’identité collective, favorisant l’expérience de l’ancrage. / This thesis deals with the way the Tandroy people native of the South of Madagascar, produce their collective identities in situation of urban migration in the city of Toliara. The Tandroy have lived for almost a century in situation of migration through the island. They are assigned most of the time to a status of precarious migrants, for whom cities remain a foreign space. I show, through an ethnography of ritual situations, how this state of the migration can be considered as a space of transition, in which a state of mobility to a state of sedentarization takes place. I also show how this passage implies the question of the building of a collective identity with the colonization, and enhanced at the beginning of the 1970s, when arises a peasant revolt led by the tandroy political leader Monja Jaona. My inquiries focus on two domains : politics and spirit possession. In both cases, urban sedentarization is expressed in a paradoxical way from the manipulation of ancestral symbols, nevertheless weakened by migrations and considered unsuitable for the urban space : hazomanga-stake, and spirit possession kokolampo. I am interested in the way these elements participate in the elaboration of symbolic constructions confronting categories articulated in the expression of a collective memory and I thoroughly observe the music produced, which can bring to an alternative relationship to the collective identity, favoring the experiment of the sedentarization.

Rural revitalization is a major concern in many developed countries where rural exodus depopulated thecountryside, including France where some rural areas suffer from demographic and economic decline. In thefirst times of the Covid 19 crisis, the perspective of an urban exodus was largely raised in the developedcountries’ press. The idea was that the pandemic was sparking disenchantment with the urban lifestyleleading to mass migration from the big cities to the countryside, thus fostering rural revitalization, possibly ata wide scale. Therefore, the aim of this study is on the one hand, to understand this Urban Exodusphenomenon and its significance in the French context through press and literature review. On the otherhand, the aim is to investigate if and how this phenomenon impacts rural revitalization, by focusing on thecases of the rural municipalities Saint-Fraimbault and Mamers. We find that the vision of the Urban Exodusfirst conveyed by the media was distorted: there has been no global reorganization of spatial and migratorypatterns in France, even though more people have been moving towards an area with a lesser populationdensity. The host territories include rural areas that were in decline before the pandemic, where the UrbanExodus represents a potential in terms of demographic and economic recovery, as well as a challenge for theirrural identity and their development model. The case studies show that the effects of the Urban Exodus onrural revitalization are not uniform. They suggest that the effects may depend on the initial developmentstrategy of the municipality. In the case of Mamers indeed, the Urban Exodus was experienced as anopportunity while the phenomenon did not have significant effects in Saint-Fraimbault.

Il concetto di rete dell'informazione può diventare uno schema logico con cui descrivere l'evoluzione delle politiche sulle energie rinnovabili e sulla sostenibilità? La ricerca è stata svolta analizzando l'architettura delle due reti (internet e reti energetiche) e l'evoluzione del bene prodotto e distribuito nella rete energetica, l'energia, esplicitando l'accessibilità da parte della distribuzione mondiale delle risorse petrolifere tradizionali e delle risorse rinnovabili. La struttura metodologica del progetto di ricerca si basa due tipi di analisi teorica: 1) l'analisi della nascita delle società in rete attraverso le teorie di Manuel Castells (concetto di spazio di flussi) e di Saskia Sassen e l'evoluzione delle città (cap.2 e cap.5) 2) le analisi dei flussi dei materiali e delle energie avendo come riferimento metodologico l'approccio ecologico ideato dai ricercatori dell'istituto per il Clima, l'Ambiente e l'Energia di Wuppertal, Germania (cap.3 e cap.4) La contraddizione tra città innovative e città che sono ai livelli di enormi discariche o di baraccopoli è esposta nel cap.6 attraverso casi studio e progetto dei Programmi Europei. Nell'ultimo capitolo (cap.7) si riassumono le ipotesi di partenza e i risultati della ricerca e si espongono le questioni aperte. / Can internet logic scheme be used as a basis to describe public policies evolution on renewable energies production and sharing in urban areas all over the world? The research project analyses the two networks (internet and energetic grids) architectures in actual and future urban areas. This analysis is connected with present and future forecasts energy productions from traditional fuels and from renewable sources. Theoretical analysis is conducted following a double conceptual pathway: - societal networks (Manuel Castells theory) and urban areas evolution (Saskia Sassen and Mike Davis) in order to picture the evolution of cities and towns in modern economies and in developing countries (Chapters 2 and 5); - Material and Energy Flow Analysis (approach by Wuppertal Institute for Climate, Environment and Energy) applied to renewable energy (Chapters 3 and 4) In Chapter 6 case studies are exposed on the deep cleavage between two different worlds: innovative, rich towns on a side and the landfills cities, slums on the other side. In the last part hypothesis and thesis are put together and open questions are explained (Chapter 7).