Assessment of hybrid model for sustainable sanitary landfill siting using geospatial and geotechnical techniques

Abstract

One of the major challenges in waste management is the issue of selecting an appropriate site for sustainable sanitary landfilling for the disposal of municipal solid waste (MSW) due to the complexity of various factors that must be considered such as environmental, economic, and social. Therefore, this research developed an innovative hybrid model based on the integration of geographic information systems (GIS), multi-criteria decision analysis (MCDA) and geotechnical technique following landfill siting guidelines and regulations. Therefore, in order to have a sustainable sanitary landfill site selection model, there is a need to evaluate geospatial and geotechnical properties of the area where the potential landfill is to be constructed. The research included identification criteria of siting sanitary landfill such as water bodies, geology, soils, elevation, slope, residential areas, archeological sites, airports, population, roads, railways, infrastructures, and land use. Due to the large volume of spatial data, GIS was used to manage, evaluate, and process these data. In addition, analytical hierarchy process (AHP) was applied to solve decision making problems where multiple alternatives and competing objectives are involved. Criteria maps obtained for this research were prepared in the GIS environment followed by the criteria weights obtained from AHP pairwise comparison matrix and normalization. Next, the weighted criteria were evaluated and overlaid through GIS software ArcGIS 10.3. Then, map production of the most suitable sites for sanitary landfill was carried out using QGIS. Finally, a hybrid model was developed by integrating geospatial and geotechnical techniques. The results from the GIS and AHP revealed the three most suitable sites for sustainable sanitary landfill site selection. This was further examined using geotechnical criteria, namely permeability, volumetric shrinkage and shear strength to obtain the best site. Additionally, computer modeling through digital image technique (using Surfer and Matlab software) was used to validate the model. The model developed from the results of this research can be used as a guide for sustainable sanitary landfilling in developed and developing countries.