Frame-Works for Study Area Boundary Delineation in Environmental Impact Assessment

The quality of environmental impact assessment (EIA) findings, as a decision support system, has always been a function of the extent of its boundaries. Meanwhile, boundaries of a study area can be delineated physically or non-physically according to the EIA working units or methodologies. Six case studies have been conducted to consider the study areas of variety of EIAs namely, visual, cumulative, forest-degradation due to population growth, air and river pollution. For each case study, we considered dominant constrains and EIA objectives that were desired in the EIA procedure. In the end, frameworks were introduced to delineate the boundary of study area in different EIAs. For instance, the boundary in a highly mountainous area was delineated according to constrains of topography, water-line of a dam lake for EIA of a dam, and software limitations and interfaces for air pollutant dispersion assessments around stack gas of a thermal power plant. Overall, a complete boundary-delineation in an EIA can be achieved, if several boundaries (physical/non-physical) considered at once. For example, if the EIA study area is located near a national park, the whole park must be included to assess the project environmental impacts on the national park besides national and international considerations.