The selection and structuring of quality infrastructure projects fundamentally depend on proper assessments of their environmental and socioeconomic impacts. The area where such impacts occur is typically called the area of influence. Defining this area can be a challenge, as there is no consensus about the appropriate criteria, methodologies, and scales to use. Indeed, at the moment, there is no clear definition for the concept of area of influence, which often gets confused with the parameters used for its delimitation. In practical terms, the area of influence indicates where and to what extent those in charge of the project’s implementation should focus their efforts on analyzing, mitigating and compensating for the direct and indirect impacts of the project. At the same time, the area of influence informs the authorities where and how they must operate. Due to its critical importance in identifying and managing socio-economic and environmental risks and in guiding policy integration efforts to uphold the rights of populations affected both directly and indirectly, adequately delimiting the area of influence is essential to improve the decision-making process related to infrastructure projects.

In this technical note, researchers from Climate Policy Initiative/Pontifical Catholic University of Rio de Janeiro (CPI/PUC-Rio) (i) analyze how areas of influence are currently defined by government bodies and in the Terms of Reference (TRs) for EVTEA and EIAs for land transportation infrastructure projects; (ii) present a set of recommendations for the adoption of clearer criteria for the definition and demarcation of areas of influence for new projects, from a perspective that explicitly incorporates where the direct and indirect effects of this type of undertaking will occur; and (iii) propose a dialogue between the EVTEA and the EIA.

In Brazil, the area of influence of infrastructure projects is currently delimited in two moments: in the Feasibility Studies (Estudo de Viabilidade Técnica, Econômico e Ambiental – EVTEA), which aims to assess the economic feasibility of the project, and the Environmental Impact Assessment (Estudo de Impacto Ambiental – EIA), meant to evaluate the project’s environmental feasibility. There is a difference in the objective and scope between these two instruments which, in itself, may lead to different delimitations of projects’ areas of influence. On the other hand, both instruments, in theory, apply to the same project, which means that it is reasonable to expect that their areas of influence should somehow be related.

Within the scope of the EIA, changes to determine area of influence are currently under discussion by Brazil’s National Congress. General Environmental Licensing Bill (Legislative Bill PL 3,729/2004) and Senate Bill PLS 168/2018, both aimed at changing environmental licensing rules, restrict the concept of area of influence, proposing that it applies only to Areas of Direct Influence (Área de Influência Direta – AID), where only the direct impacts of projects are considered. In current practice, however, terms of reference for EIAs usually mandate the establishment of both an AID and an Area of Indirect Influence (Área de Influência Indireta – AII) as parameter of study. Such proposals to restrict the concept of area of influence would, therefore, preclude the need to assess the indirect effects of building and operating the projects. As a logical consequence, they also exclude these indirect effects from future socio-environmental mitigation and compensation programs. 

The aforementioned legislative bills also draw on the concept of area of influence to determine the right to participate in the decision-making process, both by limiting public hearings exclusively to people located in the areas directly influenced by the project and by restricting the intervention of bodies and entities from outside the AIDs.


  • The proposals pending before the Chamber of Deputies and the Federal Senate (PL 3729/2004 and PLS 168/2018, respectively) should restore the mandatory requirement to delimit the area of indirect influence and separate the concept of area of influence from its respective delimitation.
  • The definition of the concept of the project’s area of indirect influence should consider the area affected by changes in economic, social and environmental dynamics induced by the implementation of the infrastructure project.
  • Environmental parameters should be preliminarily incorporated into the delimitation of the area of influence within the scope of EVTEA and, subsequently, the EIA should delve into the socioeconomic and environmental impacts to refine, deepen and consolidate the delimitation process.
  • The reasoning behind the methodology used to delimit the area of direct (and, especially, indirect) influence should be transparent so that it may be checked by the competent entities, thus preventing discretionary decisions by those in charge of the EVTEA and the EIA.


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