Landfill Site Selection Model Using an Integrated Approach of GIS and Multi Criteria Decision Analysis (MCDA): Example of Selangor, Malaysia

摘要

Background and Objective: Municipal Solid Waste (MSW) is disposed mainly in the landfill. Planners face great difficulties in the selection of suitable area for waste landfill especially in urbanized state, such as Selangor due to land scarcity, land price and increased solid waste generation. The current site selection approach known as Constraint Mapping Techniques (CMT) produced weak evidence to support the selection because the evaluation was based on the exclusionary criteria only. Therefore, this study was aimed to identify the optimal suitable areas for waste landfill. Materials and Methods: Integrated approach of Geographical Information System (GIS) spatial analysis and Multi Criteria Decision Analysis (MCDA) consists of Analytical Hierarchy Process (AHP) and Weighted Linear Combination (WLC) were applied in this study. Six factors involved in the selection process namely as proximity to urban area, surface water, protected area, major road and railways, groundwater vulnerability and slope. Results: The 7% of the state or 560 km2 were suitable for MSW landfill. Majority of the sites were classified as high and very high suitability except for C13. The largest area was determined as C1, where 55% (19,168 ha) of the land have high suitability and 44% (15,555 ha) have very high suitability. All of the candidate sites were located on agriculture land, which could be a challenge to agricultural industries and food safety in Selangor. Conclusion: The model is useful to identify suitable area for landfill sites and assist the decision maker to plan for the waste landfill construction. The model used in this study is in clear form of map that was easy to explain and understood. The approach is easy to expand to other parameters.