Selection Of Solid Mine Waste Dump Sites Using GIS and Multi-Criteria Decision Techniques (AHP-TOPSIS)

Abstract

The traditional methods used in selecting mine solid waste dump sites within the Ghana Manganese Company Limited Concession (GMCL) has some limitations which include encroachment on human settlement and utilities and depletion of water bodies. Due to this, modern technology and decision making techniques were employed in selecting new mine solid waste dump sites within GMCL concession to replace the existing dump site which is close to its full capacity. The research sought to select appropriate sites for mine solid waste dump using Geographic Information System (GIS) integrated with Analytic Hierarchy Process (AHP) and the Technique for Order of Preference by Similarities to Ideal Solutions (TOPSIS) and to do a comparative analysis on the sites selected by GIS and criteria with equal importance, GIS and criteria with different weights obtained from AHP and GIS combined with weighted criteria from AHP and alternatives ranked by TOPSIS. Nine alternatives were selected within the GMCL concession of which the first alternative closer to the active mine production site was chosen as the most suitable site. GIS overlay analysis based on criteria of equal importance yielded a generalised map useful only for preliminary analysis. GIS integrated with AHP and TOPSIS produced a suitability map which is in the interest of stakeholders. Since the TOPSIS ranks alternatives based on the closeness of the alternatives to the ideal suitable site. It does not only rank based on criteria with higher weights but rather criteria with higher weights that are closer to the ideal site.