Multi-Criteria Optimisation of Landfill Site Selection Using AHP-TOPSIS-SWARA: A Case Study of Chegutu Municipality

Abstract

This study presents an integrated Multi-Criteria Decision-Making (MCDM) framework for sustainable landfill site selection in Chegutu Municipality, Zimbabwe. Combining the Analytical Hierarchy Process (AHP), Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), and Stepwise Weight Assessment Ratio Analysis (SWARA), the research evaluates three potential sites against environmental, social, economic, and technical criteria. Data were collected through expert questionnaires (n= 7) and geospatial analysis, with weights derived via AHP OS software and rankings computed using Python. Results identified Site 2 as optimal (45.3% final score), demonstrating superior performance in critical environmental factors: slope gradient (1.5%), water source proximity (6834.82 m), and settlement distance (3220 m). The hybrid methodology proved particularly effective in resolving conflicts between technical and social priorities, with environmental criteria carrying 61.1% weight in the AHP analysis. The study demonstrates how integrated MCDM approaches can improve municipal waste management decisions by systematically balancing ecological protection, public health concerns, and operational feasibility. Findings provide a transferable model for landfill site selection in developing urban contexts while highlighting the value of combining quantitative tools.