The objective of the past work was to capture the main processes, both biophysical and economic, to reproduce them in a virtual world similar to reality. There have been two stages. In a first step, the team tried to select relevant knowledge to set-up a first conceptual model. As an hydrological model was already developed (Hoanh, et al. 2001), the emphasis was put on the economic and social processes. The first idea was to work on the interactions between decisions making at different scales. Are the decisions making processes of the different stakeholders (farmers, traders, hamlet, commune, water company, etc.) well | Development of Multi-Agent Systems (MAS) model for Bac Lieu case study --- oOo --- F. Bousquet1, LC. Dung2, LA. Tuan2 1 IRRI-Cirad, Bangkok, Thailand 2 Cantho University, Vietnam 1 INTRODUCTION Beside the DFID project “Accelerating poverty elimination through sustainable resource management in coastal lands protected from salinity intrusion” a complementary modeling experiment started in September 2001. The objective is to test the use of a new methodology using Multi-Agent Systems for participatory modeling. This approach was initiated by Cirad (Bousquet, et al. 1999) and has already been developed in collaboration with IRRI. For instance this approach is developed and used by IRRI researchers in North Vietnam for the study of farmer’s practices (Castella, et al. 2001). MAS is a methodology which put emphasis on the understanding of decision making processes of different stakeholders, linked to bio-physical dynamics. Thus, it seems to be a method complementary to the others method already used in DFID project (spatial analysis for land management unit, hydrological modeling and economic survey). It may be helpful for the integration of knowledge coming from different disciplines. It has been decided to conduct a one year project on MAS modeling to train the participants and assess if this method is relevant and of some interest for the case study. The team is composed of a modeler and two scientists from Cantho University specialized in Economics and Hydrology. The IRRI-DFID project experts are also participating by delivering the expert knowledge and giving access to the data collected. In January 2002 the team met for the first time with the DFID project to discuss on the issues and dynamics at stake. Then, during April 2002 the modeling team produced a conceptual model of farmers’ decision-making process that is presented in this paper. The objective is to inform and provoke discussions with researchers and stakeholders and orient the research for the remaining
