New Development of Methods for Environmental Impact Assessment Facing Uncertainty and Cumulative Environmental Impacts

불확실성과 누적환경영향하에서의 환경영향평가를 위한 방법론의 새로운 개발

At both international and national levels, such as in the Rio Declaration and the EU's Fifth Environmental Action Plan, governments have committed themselves to the adoption of the precautionary principle (UNCED 1992, CEC 1992). These commitments mean that the existence of uncertainty in appraising policies and proposals for development should be acknowledged. Uncertainty arise in both the prediction of impacts and in the evaluation of their significance, particularly of those cumulative impacts which are individually insignificant but cumulatively damaging. The EC network of EIA experts, stated at their last meeting in Athens that indirect effects and the treatment of uncertainty are one of the main deficiencies of current EIA practice. Uncertainties in decision-making arise where choices have been made in the development of the policy or proposal, such as the selection of options, the justification for that choice, and the selection of different indicators to comply with different regulatory regimes. It is also likely that a weighting system for evaluating significance will have been used which may be implicit rather than explicit. Those involved in decision-making may employ different tolerances of uncertainty than members of the public, for instance over the consideration of the worst-case scenario. Possible methods for dealing with these uncertainties include scenarios, sensitivity analysis, showing points of view, decision analysis, postponing decisions and graphical methods. An understanding of the development of cumulative environmental impacts affords not only ecologic but also socio-economic investigations. Since cumulative impacts originate mainly in centres of urban or industrial development, in particular an analysis of future growth effects that might possibly be induced by certain development impacts. Not least it is seen as an matter of sustainability to connect this issue with ecological research. The serious attempt to reduce the area of uncertainty in environmental planning is a challenge and an important step towards reliable planning and sustainable development.