Ex Ante Impact Assessment of Reservoir Construction Projects for Different Stakeholders Using Agent-Based Modeling

Reservoir construction projects are frequently met with fierce opposition. Consequently, to mitigate any potential negative impacts, environmental and social impact assessments are usually mandatory. Stakeholder perspectives are often only implicit in such assessments, and the medium-term effects of mitigating actions are assessed at the aggregate level, which fails to take into account unequal disaggregated impacts. In this paper, we design and apply an agent-based model (ABM) built on stakeholder information to conduct an ex ante assessment of the impact of a reservoir construction project in southern Thailand over a 30-year period for individual agents. We incorporate stakeholders’ knowledge into the ABM on the basis of primary data collected during the 2016–2018 period, including workshops with affected farmers to assess their interests and concerns, in-depth interviews with farmers in nearby districts to assess farming behaviors, and the expert opinions of policymakers to assess the relevant regulations and processes. In a case study for which the model was established, the results predict that, overall, farmers will have more farm income if the dam is built. We find that affected people require a standard of living similar to that provided by their previous livelihood as soon as possible after resettlement. By simulating the impacts on individual agents, we conclude that the compensation for relocation offered to affected farmers is not sufficient for sustainable resettlements. Facilitating compensation may increase the speed of project implementation and lead to better outcomes for everyone, including affected communities, whereas failure to reshape the current compensation policy leaves everyone more disadvantaged.