Transhumant pastoralist are highly dependent on their landscape. Their economic, cultural and political systems are directly shaped by and shaping space. The nomadic nature of transhumant pastoralists have therefore created unique pastoral socio-spatial relations. Due to their close interaction with local landscapes, land use change can heavily impact their socio- spatial relations and their spatial justice. This study therefore studied the impacts of the case of the Great Green Wall, a large-scale land use change project focusing on afforestation and land management, on transhumance pastoralists from a spatial justice lens. The study focused on de jure spatial justice through policy documents and perceived spatial justice through interviews with stakeholders, specifically in terms of recognition, procedural rights, and distributional effects. This study found that (1) the project did not recognise the socio-spatial relations of pastoralists and instead, pastoralists were perceived as having a negative influence on the landscape, (2) de jure procedural justice was lacking, and stakeholders perceived the role of pastoralists in the governance and implementation of the project as limited, and (3) policy documents revealed a lacking focus on the distributive effects on pastoral socio-spatial relations, and the perceived spatial justice in terms of mobility and access to spatial resources was low. Overall, the levels of both de jure and perceived spatial justice were interpreted as low, meaning that the Great Green Wall has negative impacts on pastoral socio-spatial relations and pastoralists’ ability to influence these.

La Grande muraille verte est le nom d’un programme régional de lutte contre la désertification au Sahel lancé en 2007 sous l’égide de l’Union africaine et des organisations régionales. Il consiste à favoriser le reboisement des territoires semi-arides le long d’un tracé reliant Dakar à Djibouti et traversant onze États, afin de créer un « bandeau végétal dressé face à l’avancée du désert ». Cette thèse a pour but de proposer une lecture géographique et critique de ce projet insolite, appréhendé ici comme une utopie environnementale. À partir d’enquêtes de terrain principalement menées au Sénégal (région du Ferlo) et enrichies par les apports de la political ecology, elle met en lumière la tension qui existe entre d’un côté, la formulation d’un projet de territoire au nom du développement des zones semi-arides et de la gestion des ressources naturelles et, de l’autre, la promotion d’un instrument d’extraversion politique et économique permettant de capter de nouvelles rentes environnementales : en quoi la territorialisation du projet est-elle subordonnée à une quête de visibilité globale ? La première partie montre comment la Grande muraille verte recycle dans un moment historique favorable des pratiques anciennes en matièr ede lutte contre la désertification. La deuxième partie décrit le déficit d’ancrage territorial de ses aménagements à l’échelle locale. La troisième partie montre que l’appropriation globale du projet est la source principale de sa grande résilience. / The Great Green Wall is a regional initiative to combat desertification in the Sahel. It was launched in2007 under the leadership of the African Union and other regional organisations. The program supports reforestation of drylands from Dakar to Djibouti, and aims to form a line of trees protecting against desert encroachment. In a geographical and critical perspective, it can regarded as a green utopia. This thesis, based essentially on field research carried out in Senegal (Ferlo region) supplemented by political ecology insights sheds light on the existing tension between two approaches to the project : one, the objectives of this local project are to develop drylands and better manage natural resources, and two, it can also be seen as promoting an instrument of political and economic extraversion, producing newrent-seeking opportunities. To what extent can the territorialization process of the local project be impaired by the search for global visibility ? The first part shows how the Great Green Wall, at a historical moment, is reactivating traditional techniques to combat desertification. The second partdescribes the lack of territorial anchorage and its local applications. The third part shows that the project derives its great resilience mainly from global ownership.