Strategic Choices and Resolution of Water Allocation Conflicts With GMCR+

The growing pressure on water resources, intensified by factors such as climate change, increasing agricultural demand, and urban expansion, has amplified the occurrence of conflicts in semi-arid regions. This study analyzes water allocation conflicts in Ceará, Brazil, focusing on the inter-regional transfer between the Middle Jaguaribe River Basin and the Metropolitan Region of Fortaleza. The research employed a three-stage methodological approach: (i) identification and classification of conflicts documented in the minutes of River Basin Committees (2004–2021); (ii) selection of a real conflict for analysis; and (iii) modeling with the Graph Model for Conflict Resolution (GMCR+). A total of 111 conflicts were identified, with water allocation being the most recurrent category. The selected case refers to the Castanhão reservoir, the main source of the transfer. The modeling included three decision makers — irrigators, the Water Resources Management Company (COGERH), and urban users — resulting in 256 possible states, of which 112 were feasible. The analysis revealed one equilibrium state (state 106), robust to variations in preferences, characterized by the prioritization of human supply, the adoption of alternative sources, and the rejection of irregular withdrawals. The results demonstrate that even under structural scarcity, stable solutions can emerge through adaptive and participatory governance frameworks. By integrating a decision-support model into an empirical governance context, this study contributes to a broader understanding of how analytical tools like GMCR + can inform conflict resolution and cooperative water management in drought-prone regions globally.