Advancing participatory decision support system in water management: An agent-based model for socially-informed collective allocation

Abstract

Modeling human–water interactions becomes increasingly vital for sustainable water governance as climate variability and population growth intensify water conflicts. This paper presents an agent-based model that integrates hydrological and social dynamics to support decision-making in river basin water allocation. Designed using the Tropos methodology and implemented on the GAMA platform, the model captures stakeholder behaviors, preferences, and interactions in various collective allocation scenarios. Using real irrigation data from the Brazilian Formoso River Basin (FRB) , the model simulates strategic cooperation among water users and regulators . Under a cooperative collective allocation scenario, the cumulative withdrawal in the FRB was found highly sensitive to water availability, whereas non-cooperative collective behaviour led to higher cumulative consumption ($>$3.0 × 10⁶ m${}^3$) and no reduction was observed near critical periods. The framework is adaptable for other river basins with different dynamic agent profiles and negotiation mechanisms.