Evaluating the effectiveness of EIA review for onshore wind power projects in South Korea using multi-criteria analysis

Environmental Impact Assessment (EIA) systems play a crucial role in systematically reviewing and analyzing the potential environmental impacts of development plans, contributing significantly to environmental conservation. However, there is a growing demand to evaluate the practical effectiveness of EIA. This study introduces a novel quantitative assessment of EIA effectiveness, in contrast to the traditionally used qualitative approaches. A data-driven framework was employed to provide an objective measurement of environmental performance improvements before and after the EIA review. The overall objective of this study was to quantitatively evaluate the effectiveness of the EIA review process for onshore wind power projects (WPPs) in South Korea over the last decade (2013−2022) using an Environmental Assessment Index (EA-Index) based on a multi-criteria analysis. The EA-Index, comprising 23 indicators in three components (natural environment, resource conservation, and living and social environment), weighted by the Analytic Hierarchy Process (AHP), provides a structured and objective method to measure environmental performance before and after an EIA review. The results showed a general improvement in environmental performance post-approval, with the average EA-Index for 79 WPPs increasing from 105.4 to 117.9 and success rates exceeding the reference value of 100 increasing from 60.8 % to 74.4 %. This improvement was driven by significant increases in the indicators within the natural environment. The significant improvements observed from 2017 to 2020 reflect the impact of the revised EIA guidelines and stricter evaluation criteria. This study highlights the need for tailored EIA guidelines to address site-specific characteristics, enhanced stakeholder engagement, and continuous policy refinement to support sustainable development. The EA-Index proved to be a robust tool for evaluating EIA effectiveness, providing critical policy implications and recommendations. • EA-Index was employed to evaluate EIA effectiveness for onshore wind power. • Significant environmental improvements were observed after the EIA review. • Environmental sensitivity and site-specific impacts were effectively captured. • EA-Index proved robust for evaluating EIA effectiveness in onshore wind projects. • Tailored EIA guidelines and policy improvements support sustainable development.