T HE field of decision support has been the subject of research conducted by several scientists of various fields. Therefore, it has constituted an attractive pole for different studies and applications. Among these applications, we find several cases which are related to problems with spatial reference: urban and regional planning, transport, management of water resources, environmental management, evaluation of the territory and location of industrial activities, etc. The problems which are related to the area of spatial decision support focus on the selection of geographical sites [14] [4] [37]. This latter is based on the choice between several sets of physical criteria [12] [13].Moreover, decision support systems aim to help decision makers in their tasks by providing them with all the relevant elements for decision-making and spatial planning. In fact, territorial decision support involves several conflicting criteria, whose importance are not the same. The territorial decision support involves several decisionmakers and institutions, which generally have divergent preferences and objectives where various points of view must be taken into account for a final decision [23]. The decision appears as a compromise between several interests and divergent points of view that imply the use of a negotiation strategy between the various involved actors who must take decisions as quickly as possible by taking into account a functioning constrained time. Consequently, this permits to obtain an answer to an interrogation before a given deadline in order to allow decision makers to act as quickly and appropriately as possible.Territory planning (TP) is based on a prospective and strategic vision that takes into account the potential, physical, social, economic, and environmental constraints of the concerned territory [14]. This type of problem involves several decision makers (persons and institutions) with different interests who have generally divergent preferences and objectives and whose different points of view must be taken into account for public decision.The realization of spatial localization in TP relies on mathematical methods and computer tools such as geographical information systems (GIS). The application of GIS is oriented to several areas: urban development [39], environmental management [10], the territory evaluation [12], industrial diagnosis [41] etc.More particularly, spatial decision support systems are interesting, especially in the development of a model of group decision support which is dedicated to the problems of space localization in TP: the problem which entails the search for a surface on a geographical map satisfying a set of criteria and finding a compromise between several interests that appeal to the expertise of several people, particularly those which are concerned by the decision.However, the group of decision-makers will be modeled by a set of entities called computer agents. These agents represent each decisionmaker in a multi-agent system (MAS) [11] [27].The problem addressed in th...