MULTI-FACTOR GIS MODELLING FOR SOLID WASTE DUMPSITES IN LILONGWE

Abstract

Solid waste disposal is an essential component of any waste management system; however, locating appropriate solid waste disposal sites is regarded as the primary issue in solid waste management. Disposal site selection is a step-by-step process in which environmental, engineering, and economic criteria are applied successively. This research aimed at identifying additional suitable sites for solid waste dumping in Lilongwe that do not pose logistical and operational challenges to improve efficiency in waste management. It assessed the suitability of the current dumpsite at Area 38 in Lilongwe City, examined site selection methods for solid waste disposal, and developed a multi-factor GIS model for the identification of suitable dumpsites in Lilongwe. A blended approach to research design was used in this research, and the study considered 10 factors: slope, rivers, soil types, built-up areas, airport, forests, wetlands, current dumpsite, roads, and railways. The findings recommend the closure of the current dumpsite and its relocation to a more suitable place because it is close to residences and creates major health risks. Additionally, the research reveals that the most popular techniques for choosing the location of a solid waste disposal facility are the Analytic Hierarchy Process (AHP) and Weighted Linear Combination (WLC) coupled with GIS. Further, the findings showed that of the 46, 283 ha, 84.07% (38, 909 ha) are unsuitable, 14.97% (6, 928 ha) are suitable and 0.96% (446 ha) are highly suitable for solid waste disposal sites. Finally, the results show that 6 sites, with capacities ranging from 28 to 94 ha, were identified using the multi-factor GIS model developed in this study.