Optimal Solid Waste Landfill Site Identification Employing GIS-Based Multi-Criteria Decision Analysis Within the Thach That District, Hanoi, Vietnam

Abstract

The principal aim of this investigation was to identify optimal locations for solid waste landfill in the Thach That district of Hanoi. Employing Geographic Information System (GIS) and Multi-Criteria Decision Analysis (MCDA), nine thematic layers were assessed as pivotal criteria, including proximity to surface water, distance to historical and cultural sites, distance to rural population areas, proximity to waste collection points, current land use status, and slope. A Boolean logic model was applied based on the criteria outlined in the Vietnamese standard TCVN 6696: 2009, and Analytical Hierarchical Process (AHP) methodology was utilized for the analysis of the remaining criteria. The study results showed that 10,641.40 hectares were unsuitable, 7,867.60 hectares were less suitable and 220.89 hectares were suitable for a landfill, corresponding to 56.81%, 42.01%, and 1.18% of the study area, respectively. In terms of size, there are two unsatisfactory zones because the area is too small. Although the distance from suitable locations to some communes in Thach That district is quite far, about 20km, it is equivalent to the distance to the current. Therefore, these positions are accepted. This research has profound significance because it contributes to adding scientific basis for choosing landfill locations not only in Thach That district but also in Vietnam.