SINUSE: a multi-agent model to negotiate water demand management on a free access water table

Many water tables are currently overexploited throughout the world. This situation raises the question of their management. Integrated management of such systems, established in both supply and demand areas, calls for thorough knowledge of the functioning of both the water table and its users, so models are usually required. This study is based on the case of the Kairouan water table, located in Tunisia, which has been continuously and globally decreasing for more than 20 years, due to overexploitation by private irrigators. The field study led to the hypothesis that the dynamics of the system is heavily influenced by local interaction between the resource and its users, and by direct, non-economic interaction between the farmers. The literature shows that several kinds of model have already been used to represent interaction between a water table and its users but none of them are able to take this kind of social behaviour into account. The simulator of a water table and user interaction (SINUSE) based upon multiagent systems enabled us to overcome these limitations. This model proved to be very useful for representing a complex and distributed system such as the Kairouan water table. It enabled us to explore the interaction between the physical and socio-economic components of the system and to conclude that local and non-economic behaviour do have a major impact on the global dynamics of the system and must therefore be taken into account. The management interventions simulated with the SINUSE model have raised interesting questions, leading to the conclusion that this model could provide a useful tool for negotiating the integrated management of the water table system. Though this model is rather specific, the approach developed could be transferred to other water table systems, to improve the knowledge of their functioning and examine the possible impacts of different management tools. (C) 2003 Elsevier Science Ltd. All rights reserved.