Impact assessment: tiering approaches for sustainable development planning and decision-making of a large infrastructure project.

The objective of this paper is to analyze a tiering scoping approach developed to identify critical multidimensional sustainability issues and impacts of a large infrastructure project: the land transport project linking northern Brazil with a new port on Guyana's coast. The Inter-American Development Bank awarded a technical assignment to develop the terms of reference of a country environmental assessment, a strategic environmental and social assessment and an environmental and social impact assessment of the project(s). The complexity of the issues at stake lead to the design of a tiered assessment process supported by wide-ranging participative sessions involving 170 individuals from Guyana and Brazil and from diverse sectors. The process identified ex ante conditionalities, critical factors for decision-making and valued socioenvironmental and governance components. Such complex and determinant planning initiatives for the future of a country need to be supported by comprehensive, well-sequenced scoping processes. [ABSTRACT FROM AUTHOR]