Oscar Retamal

One of the greatest challenges in Environmental Assessment (EA) has been the proper handlig of trade-offs. Ordered Weighted Averaging (OWA) provides a way of managing the degree of trade-off when performing Spatial Multi-Criteria Decision Analysis (GIS-MCDA). Although OWA is commonly used for the solution of Decision Spaces using Multi-Criteria Evaluation (MCE), there is no literature describing the use of OWA as a methodology using Least-Cost Path Analysis (LCA). The purpose of this research was to integrate OWA and LCA into one methodology in order to generate alternative solutions for linear projects, depending on the level of trade-off between project criteria.

A hydro corridor development proposal in Northern Ontario was used as a case study to evaluate the practicality and validity of the proposed methodology. This study demonstrates the Ordered Weighted Averaging can serve as an integrative framework to both technical and participatory requirements demanded by Ontario Class Environmental Assessment for Transmission Lines. However, this study also found that the results are affected by the type of functions used to standardize data, and that differences in suitability scales make it difficult to compare alternatives directly.

Keywords: Environmental Assessment, Criteria trade-off, Multi-Criteria Evaluation, Least-cost Path Analysis, Ordered Weighted Averaging