Résumé
In the Sahara, intensive groundwater use has allowed the development of new agrarian dynamics. In Algeria, though traditional oases were in difficulty, some Saharan wilayas (districts) became the centre point for agriculture. During the 1980's, in these regions, the government launched pilot projects in intensive agriculture, especially in cereals like the California and Saudi model (Cote, 2002). Private investments were also encouraged through a law formalizing access to landownership for agricultural development (the 1983 land tenure law; APFA). New agrarian dynamics, such vegetables crops under greenhouses started to appear. In the 1990's, despite the failure of large cereal farms model, the government has continued to make significant investments in the development of new agricultural areas in different Saharan districts (agricultural and rural electrification, opening roads and farm tracks, drilling programs, etc.). In the early 2000s,t he dynamics of these territories was consolidated by the national plan for rural development (NADP) (Hartani et al. 2011). Biskra is one of the wilaya where neo-Saharan agriculture has known a remarkable development. Vegetable crops under greenhouse combined with traditional palm tree have developed and expanded rapidly on new land. Through experts have predicted a rapid decline of this Saharan agriculture, the high profitability of plasticulture supports not diversification of agricultural production systems but also expansion of palm trees (Amichi, 2012). This pioneer front remains a pole of attraction for private investors and Algerian farmers. In this study, undertaken in the municipality of El Ghrouss (wilaya of Biskra), we discussed and analyzed how this socio-ecological system (SES) adapt to both internal and external perturbations. We showed that the robustness of this SES, ie "the capacity of the system to maintain performance when subjected to internal and external perturbations" (Janssen and Anderies, 2007), is largely made possible by complex relationships between actors, both at farms and collective level. At farm level, the relations between the actors were analyzed through agrarian contracts and showed that these contracts enable the expansion of the oasis and allow the upward social mobility. At collective and public level, the relationships between users and resources providers were analyzed through the framework proposed by Anderies et al (2004). The evidence confirms, in large part, the proposed hypothesis of Anderies et al (2004) assuming that "the link between resource users and public infrastructure providers is a key variable affecting the robustness of Sess." The complex relationships between actors, both at farms and collective level, reconfigure the institutional framework governing the use of groundwater resources. Despite its significant growth potential, this new Saharan agriculture raises many questions about its sustainability, especially because of goundwater overexploitation. In the long term, robustness and resilience of this new agriculture is difficult to measure. Similar studies case situations in the world raises similar challenges, particularly in terms of collective management of water resources when water availability reaches a critical threshold. (Texte intégral)